2021/10/21 更新

写真a

ゾンネンシャイン フォルカ トーマス
SONNENSCHEIN Volker Thomas
SONNENSCHEIN Volker Thomas
所属
大学院工学研究科 エネルギー理工学専攻 エネルギー流体工学 特任助教
職名
特任助教

学位 2

  1. 博士 ( 2015年1月   ユバキュラ大学 ) 

  2. 修士 ( 2008年5月   マインツ大学 ) 

研究キーワード 1

  1. Laser spectroscopy, Radioisotopes, Trace analysis

所属学協会 2

  1. Japanese Society of Applied Physics

    2015年4月 - 現在

  2. Germany Physical Society (DPG)

    2007年1月 - 現在

 

論文 83

  1. Odd-parity autoionizing levels of uranium observed by two-color two-step photoionization optogalvanic spectroscopy

    Miyabe M., Sato Y., Wakaida I, Terabayashi R., Sonnenschein V, Tomita H., Zhao Y., Sakamoto T.

    JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS   54 巻 ( 14 )   2021年7月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Physics B: Atomic, Molecular and Optical Physics  

    Two-color two-step photoionization optogalvanic spectroscopy was performed using high-repetition-rate titanium sapphire lasers and a uranium hollow cathode lamp to find the two-step resonance ionization schemes of uranium. Many ionization transitions were observed by exciting uranium atoms in a ground state into five, even parity, excited levels with the first-step laser and by scanning the second-step laser wavelengths. By blocking the first-step laser, single-color, two-photon ionization transitions were also identified. From these results, we have found more than 50 odd-parity autoionizing levels of uranium in the energy, ranging from the ionization potential (49958.4 cm−1) to 51 150 cm−1. The determined energy levels are within ∼±1 cm−1 of previously reported values.

    DOI: 10.1088/1361-6455/abf89f

    Web of Science

    Scopus

  2. 超高感度赤外レーザー吸収分光に基づくトリチウム分析に向けた基礎検討

    岩元 一輝, 寺林 稜平, Volker Sonnenschein, 奥山 雄貴, 齊藤 圭佑, 吉田 賢二, 西澤 典彦, 富田 英生

    アイソトープ・放射線研究発表会   1 巻 ( 0 )   2021年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:公益社団法人 日本アイソトープ協会  

    <p>超高感度赤外レーザー吸収分光(Cavity Ring Down Spectroscopy:CRDS)に基づく迅速・簡便かつ高感度なトリチウム分析法の開発を目指している。対象分子種として水分子を選定し、安定同位体や大気構成分子の干渉の少ないHTO倍音吸収2ν<sub>1</sub>bandの吸収線を用いることで実現される検出限界を見積もった。また、2 µm CRDSプロトタイプシステムを構築し、安定H<sub>2</sub>Oのスペクトルを取得した。</p>

    DOI: 10.50955/happyokai.1.0_92

    CiNii Article

  3. Disentangling decaying isomers and searching for signatures of collective excitations in β decay

    Guadilla V., Fallot M., Algora A., Tain J.L., Agramunt J., ystö J., Briz J.A., Cucoanes A., Eronen T., Estienne M., Fraile L.M., Ganioǧlu E., Gelletly W., Gorelov D., Hakala J., Jokinen A., Jordan D., Kankainen A., Kolhinen V., Koponen J., Lebois M., Meur L.L., Martinez T., Monserrate M., Montaner-Pizá A., Moore I., Nácher E., Orrigo S.E.A., Penttila H., Pohjalainen I., Porta A., Reinikainen J., Reponen M., Rinta-Antila S., Rubio B., Rytkönen K., Shiba T., Sonnenschein V., Sonzogni A.A., Valencia E., Vedia V., Voss A., Wilson J.N., Zakari-Issoufou A.A.

    Journal of Physics: Conference Series   1643 巻 ( 1 )   2020年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Physics: Conference Series  

    In this contribution we summarize the recent study of the β decay of neutron-rich nuclei with isomeric states close in energy to the ground states. The disentanglement of each pair of β-decaying states was achieved by applying different strategies and using the purification capabilities of the JYFLTRAP double Penning trap system at the Ion Guide Isotope Separator On-Line facility in Jyvaskyla. The Total Absorption γ-ray Spectroscopy technique was employed to determine the β intensity probabilities populating the excited states in the daughter nuclei. Previously undetected β intensity was found and we have already evaluated the impact of part of these results on reactor summation calculations. The possibility to populate states associated with the Pygmy Dipole Resonance in the β decay of 96gsY has also been investigated thanks to the sensitivity of our technique to high-lying strength in the daughter nuclei.

    DOI: 10.1088/1742-6596/1643/1/012134

    Scopus

  4. Determination of beta-decay ground state feeding of nuclei of importance for reactor applications

    Guadilla V, Tain J. L., Algora A., Agramunt J., Jordan D., Monserrate M., Montaner-Piza A., Orrigo S. E. A., Rubio B., Valencia E., Briz J. A., Cucoanes A., Estienne M., Fallot M., Le Meur L., Porta A., Shiba T., Zakari-Issoufou A-A, Aysto J., Eronen T., Gorelov D., Hakala J., Jokinen A., Kankainen A., Kolhinen V. S., Koponen J., Moore I. D., Penttila H., Pohjalainen I, Reinikainen J., Reponen M., Rinta-Antila S., Rytkonen K., Sonnenschein V, Voss A., Fraile L. M., Vedia V., Ganioglu E., Gelletly W., Lebois M., Wilson J. N., Martinez T., Nacher E., Sonzogni A. A.

    PHYSICAL REVIEW C   102 巻 ( 6 )   2020年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review C  

    In β-decay studies the determination of the decay probability to the ground state (g.s.) of the daughter nucleus often suffers from large systematic errors. The difficulty of the measurement is related to the absence of associated delayed γ-ray emission. In this work we revisit the 4πγ-β method proposed by Greenwood and collaborators in the 1990s, which has the potential to overcome some of the experimental difficulties. Our interest is driven by the need to determine accurately the β-intensity distributions of fission products that contribute significantly to the reactor decay heat and to the antineutrinos emitted by reactors. A number of such decays have large g.s. branches. The method is relevant for nuclear structure studies as well. Pertinent formulas are revised and extended to the special case of β-delayed neutron emitters, and the robustness of the method is demonstrated with synthetic data. We apply it to a number of measured decays that serve as test cases and discuss the features of the method. Finally, we obtain g.s. feeding intensities with reduced uncertainty for four relevant decays that will allow future improvements in antineutrino spectrum and decay heat calculations using the summation method.

    DOI: 10.1103/PhysRevC.102.064304

    Web of Science

    Scopus

  5. Mass spectral database for TOF-SIMS of stable isotopes of Sr and Zr

    Zhao Yue, Yoshida Takeru, Ohmori Yuzuka, Miyashita Yuta, Morita Masato, Sakamoto Tetsuo, Kato Kotaro, Terabayashi Ryohei, Sonnenschein Volker, Tomita Hideki, Kawai Toshihide, Okumura Takeo, Satou Yukihiko, Wakaida Ikuo, Miyabe Masabumi

    SURFACE SCIENCE SPECTRA   27 巻 ( 2 )   2020年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Surface Science Spectra  

    Nuclear accidents (e.g., at the Chernobyl and Fukushima Daiichi nuclear power plants) release considerable amounts of radioactive pollutants into the environment. Radioactive particles in dust and soil can range from a few micrometers to several micrometers in size. Detection of these micrometer-sized particles requires a fast and effective analytical method. Because time-of-flight secondary ion mass spectrometry (TOF-SIMS) exhibits high spatial resolution and parallel detection capability, it is suitable for analyzing micrometer-sized radioactive particles. However, due to isobaric interferences, TOF-SIMS cannot effectively distinguish between isobaric elements such as 90Sr and 90Zr. Resonant ionization sputtered neutral mass spectrometry (R-SNMS) eliminates isobaric interferences and enables the measurement of isotope ratios of isotopes approaching the detection limit. However, R-SNMS cannot be performed independently because its results are based on the TOF-SIMS spectra. This study provides a database of reference spectra for Sr and Zr stable isotopes, which can act as important reference for further analysis of radioactive particles in environmental samples.

    DOI: 10.1116/6.0000367

    Web of Science

    Scopus

  6. Mid-infrared cavity ring-down spectroscopy using DFB quantum cascade laser with optical feedback for radiocarbon detection

    Terabayashi Ryohei, Saito Keisuke, Sonnenschein Volker, Okuyama Yuki, Iguchi Testuo, Yamanaka Masahito, Nishizawa Norihiko, Yoshida Kenji, Ninomiya Shinichi, Tomita Hideki

    JAPANESE JOURNAL OF APPLIED PHYSICS   59 巻 ( 9 )   2020年9月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    Web of Science

  7. Mid-infrared cavity ring-down spectroscopy using DFB quantum cascade laser with optical feedback for radiocarbon detection

    Terabayashi R., Saito K., Sonnenschein V., Okuyama Y., Iguchi T., Yamanaka M., Nishizawa N., Yoshida K., Ninomiya S., Tomita H.

    Japanese Journal of Applied Physics   59 巻 ( 9 )   2020年9月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Japanese Journal of Applied Physics  

    A linewidth reduction of a distributed feedback quantum cascade laser (DFB-QCL) based on optical feedback for a mid-infrared (MIR) cavity ring down spectroscopy (CRDS) 14C spectrometer is presented. A cat-eye reflector as well as a path-length enhancement by a Herriott cell were employed for a compact optical setup. The laser linewidth was evaluated by monitoring the beat frequency between the DFB-QCL and a MIR optical frequency comb (OFC). The linewidth reduction by optical feedback was clearly observed although slow frequency drifts caused by environmental changes were still visible. A low-bandwidth beat-note lock to the OFC was conducted for long-term stabilization as well as for precise frequency scanning and thereby 14C measurement by MIR CRDS with optical feedback was demonstrated successfully.

    DOI: 10.35848/1347-4065/abb20e

    Scopus

  8. Development of two-color resonant ionization sputtered neutral mass spectrometry and microarea imaging for Sr

    Zhao Yue, Yoshida Takeru, Ohmori Yuzuka, Miyashita Yuta, Morita Masato, Sakamoto Tetsuo, Kato Kotaro, Terabayashi Ryohei, Sonnenschein Volker, Tomita Hideki, Kawai Toshihide, Okumura Takeo, Satou Yukihiko, Miyabe Masabumi, Wakaida Ikuo

    JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B   38 巻 ( 4 )   2020年7月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics  

    Two-color resonant laser ionization sputtered neutral mass spectrometry offers high elemental selectivity. In this study, two-color resonance ionization in sputtered neutral Sr was confirmed by combining a grating type Ti:sapphire laser system and a time-of-flight secondary ion mass spectrometry (TOF-SIMS) system. The authors compared the ionization efficiencies of Sr of the two-color three-photon ionization scheme 1 (first step: 460.862 nm; second step: 767.519 nm) and the two-color two-photon ionization scheme 2 (first step: 460.862 nm; second step: 405.200 nm). The resonant ionization efficiency of the latter was found to be 50 times larger than that of the former. Finally, the authors mapped the microarea distribution of Sr by two-color resonant ionization sputtered neutral mass spectrometry.

    DOI: 10.1116/6.0000006

    Web of Science

    Scopus

  9. Resonant sputtered neutral mass spectrometry using multiple reflections of laser to counterbalance Doppler broadening

    Zhao Yue, Ohmori Yuzuka, Miyashita Yuta, Morita Masato, Sakamoto Tetsuo, Kato Kotaro, Sonnenschein Volker, Tomita Hideki, Kawai Toshihide, Okumura Takeo, Satou Yukihiko, Miyabe Masabumi, Wakaida Ikuo

    JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B   38 巻 ( 3 )   2020年5月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics  

    Resonant laser sputtered neutral mass spectrometry can greatly enhance the ionization efficiency of specific neutral sputtered atoms through resonant excitation using tunable laser(s). However, the laser beam cannot irradiate the entire volume where sputtered particles are moving, because the laser beam is focused. In contrast, for an extremely low concentration of target elements, it is necessary to increase the laser irradiation efficiency. Irradiation efficiency depends on both spatial coverage and resonance wavelength matching. The former can be increased by increasing the laser path length within the sputtered neutral plume. The latter depends on the relationship between the laser spectral linewidth and the Doppler broadening width caused by the velocity of sputtered neutral particles. The authors have developed a new method to improve the ionization probability of neutral particles by reflecting the laser using mirrors to increase the ionization efficiency based on the concept mentioned above.

    DOI: 10.1116/6.0000012

    Web of Science

    Scopus

  10. An experimental setup for creating and imaging He-4(2)* excimer cluster tracers in superfluid helium-4 via neutron-He-3 absorption reaction

    Sonnenschein V, Tsuji Y., Kokuryu S., Kubo W., Suzuki S., Tomita H., Kiyanagi Y., Iguchi T., Matsushita T., Wada N., Kitaguchi M., Shimizu H. M., Hirota K., Shinohara T., Hiroi K., Hayashida H., Guo W., Ito D., Saito Y.

    REVIEW OF SCIENTIFIC INSTRUMENTS   91 巻 ( 3 )   2020年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Review of Scientific Instruments  

    For the purpose of future visualization of the flow field in superfluid helium-4, clusters of the triplet state excimer 4He2* are generated along the micro-scale recoil tracks of the neutron-absorption reaction n + 3He → 3T + p. This reaction is induced by neutron irradiation of the 3He fraction contained in natural isotopic abundance liquid helium with neutron beams either from the Japan Proton Accelerator Research Complex, Materials and Life Science Experimental Facility (JPARC)/Materials and Life Science Experimental Facility or from the Kyoto University Institute for Integrated Radiation and Nuclear Science. These 4He2* clusters are expected to be ideal tracers of the normal-fluid component in superfluid helium with several advantageous properties. Evidence of the excimer generation is inferred by detection of laser induced fluorescence emitted from the 4He2* clusters excited by a purpose-built short pulse gain-switched titanium:sapphire (Ti:sa) laser operating at a wavelength of 905 nm. The setup and performance characteristics of the laser system including the Ti:sa and two continuous wave re-pumping lasers are described. Detection at the fluorescence wavelength of 640 nm is performed by using optical bandpass filtered photomultiplier tubes (PMT). Electrical noise in the PMT acquisition traces could successfully be suppressed by post-processing with a simple algorithm. Despite other laser-related backgrounds, the excimer was clearly identified by its fluorescence decay characteristics. Production of the excimer was found to be proportional to the neutron flux, adjusted via insertion of different collimators into the neutron beam. These observations suggest that the apparatus we constructed does function in the expected manner and, therefore, has the potential for groundbreaking turbulence research with superfluid helium.

    DOI: 10.1063/1.5130919

    Web of Science

    Scopus

  11. A direct diode pumped Ti:sapphire laser with single-frequency operation for high resolution spectroscopy

    Sonnenschein Volker, Tomita Hideki, Kotaro Kato, Koya Hattori, Studer Dominik, Terabayashi Ryohei, Weber Felix, Wendt Klaus, Nishizawa Norihiko, Iguchi Tetsuo

    HYPERFINE INTERACTIONS   241 巻 ( 1 )   2020年2月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1007/s10751-020-1706-4

    Web of Science

  12. A direct diode pumped continuous-wave Ti:sapphire laser as seed of a pulsed amplifier for high-resolution resonance ionization spectroscopy

    Sonnenschein Volker, Ohashi Masaya, Tomita Hideki, Iguchi Tetsuo

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS   463 巻   頁: 512 - 514   2020年1月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms  

    Progress of the development of a tunable continuous-wave directly diode-pumped Ti:sapphire laser is reported. The pump diode system based on InGaN multimode emitters in the blue-green wavelength region is characterized in terms of beam quality and output power. A prototype bow-tie resonator with a short highly doped Brewster-cut Ti:sapphire crystal was investigated. Output power scaling with the number of pump diodes and output coupling ratio as well as wavelength tuning range using a three-plate birefringent filter was measured.

    DOI: 10.1016/j.nimb.2019.03.017

    Web of Science

    Scopus

  13. Conceptual study on parasitic low-energy RI beam production with in-flight separator BigRIPS and the first stopping examination for high-energy RI beams in the parasitic gas cell

    Sonoda T., Katayama I., Wada M., Iimura H., Sonnenschein V., Iimura S., Takamine A., Rosenbusch M., Kojima T. M., Ahn D. S., Fukuda N., Kubo T., Nishimura S., Shimizu Y., Suzuki H., Takeda H., Tanigaki M., Tomita H., Yoshida K., Ishiyama H.

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2019 巻 ( 11 )   2019年11月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1093/ptep/ptz120

    Web of Science

  14. Total absorption γ -ray spectroscopy of the β -delayed neutron emitters i 137 and Rb 95

    Guadilla V., Tain J.L., Algora A., Agramunt J., Jordan D., Monserrate M., Montaner-Pizá A., Nácher E., Orrigo S.E.A., Rubio B., Valencia E., Estienne M., Fallot M., Le Meur L., Briz J.A., Cucoanes A., Porta A., Shiba T., Zakari-Issoufou A.A., Sonzogni A.A., Äystö J., Eronen T., Gorelov D., Hakala J., Jokinen A., Kankainen A., Kolhinen V.S., Koponen J., Moore I.D., Penttilä H., Pohjalainen I., Reinikainen J., Reponen M., Rinta-Antila S., Rytkönen K., Sonnenschein V., Voss A., Fraile L.M., Vedia V., Ganioǧlu E., Gelletly W., Lebois M., Wilson J.N., Martinez T.

    Physical Review C   100 巻 ( 4 )   2019年10月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review C  

    The decays of the β-delayed neutron emitters I137 and Rb95 have been studied with the total absorption γ-ray spectroscopy technique. The purity of the beams provided by the JYFLTRAP Penning trap at the ion guide isotope separator on-line facility in Jyväskylä allowed us to carry out a campaign of isotopically pure measurements with the decay total absorption γ-ray spectrometer, a segmented detector composed of 18 NaI(Tl) modules. The contamination coming from the interaction of neutrons with the spectrometer has been carefully studied, and we have tested the use of time differences between prompt γ rays and delayed neutron interactions to eliminate this source of contamination. Due to the sensitivity of our spectrometer, we have found a significant amount of β intensity to states above the neutron separation energy that deexcite by γ rays, comparable to the neutron emission probability. The competition between γ deexcitation and neutron emission has been compared with Hauser-Feshbach calculations, and it can be understood as a nuclear structure effect. In addition, we have studied the impact of the β-intensity distributions determined in this work on reactor decay heat and reactor antineutrino spectrum summation calculations. The robustness of our results is demonstrated by a thorough study of uncertainties and with the reproduction of the spectra of the individual modules and the module-multiplicity gated spectra. This work represents the state-of-the-art of our analysis methodology for segmented total absorption spectrometers.

    DOI: 10.1103/PhysRevC.100.044305

    Scopus

  15. Total absorption γ-ray spectroscopy of niobium isomers

    Guadilla V., Algora A., Tain J.L., Agramunt J., Aÿstö J., Briz J.A., Cucoanes A., Eronen T., Estienne M., Fallot M., Fraile L.M., Ganioǧlu E., Gelletly W., Gorelov D., Hakala J., Jokinen A., Jordan D., Kankainen A., Kolhinen V., Koponen J., Lebois M., Le Meur L., Martinez T., Monserrate M., Montaner-Pizá A., Moore I., Nácher E., Orrigo S.E.A., Penttilä H., Pohjalainen I., Porta A., Reinikainen J., Reponen M., Rinta-Antila S., Rubio B., Rytkönen K., Sarriguren P., Shiba T., Sonnenschein V., Sonzogni A.A., Valencia E., Vedia V., Voss A., Wilson J.N., Zakari-Issoufou A.A.

    Physical Review C   100 巻 ( 2 )   2019年8月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review C  

    The β-intensity distributions of the decays of Nb100gs,100m and Nb102gs,102m have been determined using the total absorption γ-ray spectroscopy technique. The JYFLTRAP double Penning trap system was employed in a campaign of challenging measurements performed with the decay total absorption γ-ray spectrometer at the Ion Guide Isotope Separator On-Line facility in Jyväskylä. Different strategies were applied to disentangle the isomeric states involved, lying very close in energy. The low-spin component of each niobium case was populated through the decay of the zirconium parent, which was treated as a contaminant. We have applied a method to extract this contamination, and additionally we have obtained β-intensity distributions for these zirconium decays. The β-strength distributions evaluated with these results were compared with calculations in a quasiparticle random-phase approximation, suggesting a prolate configuration for the ground states of Zr100,102. The footprint of the Pandemonium effect was found when comparing our results for the analyses of the niobium isotopes with previous decay data. The β-intensities of the decay of Nb102m, for which there were no previous data, were obtained. A careful evaluation of the uncertainties was carried out, and the consistency of our results was validated taking advantage of the segmentation of our spectrometer. The final results were used as input in reactor summation calculations. A large impact on antineutrino spectrum calculations was already reported, and here we detail the significant impact on decay heat calculations.

    DOI: 10.1103/PhysRevC.100.024311

    Scopus

  16. Generation of He-4(2)* Clusters via Neutron-He-3 Absorption Reaction Toward Visualization of Full Velocity Field in Quantum Turbulence

    Matsushita T., Sonnenschein V., Guo W., Hayashida H., Hiroi K., Hirota K., Iguchi T., Ito D., Kitaguchi M., Kiyanagi Y., Kokuryu S., Kubo W., Saito Y., Shimizu H. M., Shinohara T., Suzuki S., Tomita H., Tsuji Y., Wada N.

    JOURNAL OF LOW TEMPERATURE PHYSICS   196 巻 ( 1-2 ) 頁: 275 - 282   2019年7月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Low Temperature Physics  

    For flow visualization study of quantum turbulence in superfluid 4He, He2∗ excimers are unique tracers which follow only normal-fluid component flow above 1 K. To generate detectable small He2∗ clouds (clusters) required for full-space velocity field measurements, we have adopted a new method based on neutron absorption reaction of 3He impurities in 4He and conducted proof-of-principle experiments. Generation of the He2∗ excimers was detected by laser-induced fluorescence using photomultiplier tubes. The fluorescence was observed to increase proportionally to the neutron flux, suggesting that a sufficient amount of He2∗ excimers were generated by neutrons. We also estimated the number of He2∗ excimers possibly generated by γ-rays and found that the relevant contribution was less than 40%. Thus, the majority of the He2∗ excimers was confirmed to be generated via n-3He absorption reactions.

    DOI: 10.1007/s10909-018-02112-3

    Web of Science

    Scopus

  17. Large Impact of the Decay of Niobium Isomers on the Reactor ν e Summation Calculations

    Guadilla V., Algora A., Tain J.L., Estienne M., Fallot M., Sonzogni A.A., Agramunt J., Äystö J., Briz J.A., Cucoanes A., Eronen T., Fraile L.M., Ganioǧlu E., Gelletly W., Gorelov D., Hakala J., Jokinen A., Jordan D., Kankainen A., Kolhinen V., Koponen J., Lebois M., Le Meur L., Martinez T., Monserrate M., Montaner-Pizá A., Moore I., Nácher E., Orrigo S.E.A., Penttilä H., Pohjalainen I., Porta A., Reinikainen J., Reponen M., Rinta-Antila S., Rubio B., Rytkönen K., Shiba T., Sonnenschein V., Valencia E., Vedia V., Voss A., Wilson J.N., Zakari-Issoufou A.A.

    Physical Review Letters   122 巻 ( 4 )   2019年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review Letters  

    Even mass neutron-rich niobium isotopes are among the principal contributors to the reactor antineutrino energy spectrum. They are also among the most challenging to measure due to the refractory nature of niobium, and because they exhibit isomeric states lying very close in energy. The β-intensity distributions of Nb100gs,100m and Nb102gs,102m β decays have been determined using the total absorption γ-ray spectroscopy technique. The measurements were performed at the upgraded Ion Guide Isotope Separator On-Line facility at the University of Jyväskylä. Here, the double Penning trap system JYFLTRAP was employed to disentangle the β decay of the isomeric states. The new data obtained in this challenging measurement have a large impact in antineutrino summation calculations. For the first time the discrepancy between the summation model and the reactor antineutrino measurements in the region of the shape distortion has been reduced.

    DOI: 10.1103/PhysRevLett.122.042502

    Scopus

  18. Characterization and performance of the DTAS detector

    Guadilla V., Tain J.L., Algora A., Agramunt J., Äystö J., Briz J.A., Cucoanes A., Eronen T., Estienne M., Fallot M., Fraile L.M., Ganioğlu E., Gelletly W., Gorelov D., Hakala J., Jokinen A., Jordan D., Kankainen A., Kolhinen V., Koponen J., Lebois M., Le Meur L., Martinez T., Monserrate M., Montaner-Pizá A., Moore I., Nácher E., Orrigo S.E.A., Penttilä H., Pohjalainen I., Porta A., Reinikainen J., Reponen M., Rice S., Rinta-Antila S., Rubio B., Rytkönen K., Shiba T., Sonnenschein V., Sonzogni A.A., Valencia E., Vedia V., Voss A., Wilson J.N., Zakari-Issoufou A.A.

    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment   910 巻   頁: 79 - 89   2018年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment  

    DTAS is a segmented total absorption γ-ray spectrometer developed for the DESPEC experiment at FAIR. It is composed of up to eighteen NaI(Tl) crystals. In this work we study the performance of this detector with laboratory sources and also under real experimental conditions. We present a procedure to reconstruct offline the sum of the energy deposited in all the crystals of the spectrometer, which is complicated by the effect of NaI(Tl) light-yield non-proportionality. The use of a system to correct for time variations of the gain in individual detector modules, based on a light pulse generator, is demonstrated. We describe also an event-based method to evaluate the summing-pileup electronic distortion in segmented spectrometers. All of this allows a careful characterization of the detector with Monte Carlo simulations that is needed to calculate the response function for the analysis of total absorption γ-ray spectroscopy data. Special attention was paid to the interaction of neutrons with the spectrometer, since they are a source of contamination in studies of β-delayed neutron emitting nuclei.

    DOI: 10.1016/j.nima.2018.09.001

    Scopus

  19. Towards in-jet resonance ionization spectroscopy: An injection-locked Titanium:Sapphire laser system for the PALIS-facility

    Reponen M., Sonnenschein V., Sonoda T., Tomita H., Oohashi M., Matsui D., Wada M.

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   908 巻   頁: 236 - 243   2018年11月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment  

    This article presents a pulsed narrowband injection-locked Titanium:Sapphire laser aimed for high-resolution in-jet resonance ionization spectroscopy at the SLOWRI/PALIS at RIKEN. The laser has been integrated into the PALIS laser laboratory enabling it to be utilized with the existing broadband Titanium:Sapphire and dye lasers. The seed efficiency has been evaluated to be close to unity over the master laser wavelength range ∼ 753 to 791 nm, and the slope efficiency, namely the ratio of the pump power to the output power, was determined to be ∼ 30 % at 780 nm. A two-step ionization scheme with 386.4016 nm first step and 286.731 nm second step into an autoionizing state was developed for resonance ionization spectroscopy of 93Nb. Magnetic hyperfine coupling constants of 1866±8 MHz and 1536±7 MHz were measured for the ground and excited state, respectively, in a good agreement with the literature values. A Gaussian dominated Voigt linewidth of 434.5 ± 7.4 MHz was extracted from the hyperfine spectra measured for niobium. In addition, the resolution of the in-jet resonance ionization in PALIS is estimated through numerical methods.

    DOI: 10.1016/j.nima.2018.08.073

    Web of Science

    Scopus

  20. Isotope-selective Microscale Imaging of Radioactive Cs without Isobaric Interferences Using Sputtered Neutral Mass Spectrometry with Two-step Resonant Ionization Employing Newly-developed Ti:Sapphire Lasers.

    Sakamoto T, Morita M, Kanenari K, Tomita H, Sonnenschein V, Saito K, Ohashi M, Kato K, Iguchi T, Kawai T, Okumura T, Satou Y, Wakaida I

    Analytical sciences : the international journal of the Japan Society for Analytical Chemistry   34 巻 ( 11 ) 頁: 1265 - 1270   2018年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Analytical Sciences  

    The characterization of radionuclides in Fukushima is important to determine their origins and current state in the environment. Radionuclides exist as fine particles and are mixed with other constituents. A measurement method with both micro-imaging capability and highly selective element detection is necessary to analyze these particles. We developed such an imaging technique using a time-of-flight secondary ion mass spectrometry and wavelength-tunable Ti:Sapphire lasers for the resonance ionization of target elements without mass interference. This is called resonant laser ionization sputtered neutral mass spectrometry. The instrument has a high lateral resolution and a higher ionization selectivity using two-step resonance excitation of Cs with two lasers at different wavelengths. Optimization of the wavelength for resonance ionization using a Cs compound was performed, and a real environmental particle containing radioactive Cs was analyzed. Isotope images of three kinds of Cs were successfully obtained without interfere from Ba isotopes for the first time.

    DOI: 10.2116/analsci.18P249

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    PubMed

    CiNii Article

  21. Isotope-selective Microscale Imaging of Radioactive Cs without Isobaric Interferences Using Sputtered Neutral Mass Spectrometry with Two-step Resonant Ionization Employing Newly-developed Ti:Sapphire Lasers

    Sakamoto Tetsuo, Morita Masato, Kanenari Keita, Tomita Hideki, Sonnenschein Volker, Saito Kosuke, Ohashi Masaya, Kato Kotaro, Iguon Tetsuo, Kawai Toshihide, Okumura Takeo, Satou Yukihiko, Wakaida Ikuo

    ANALYTICAL SCIENCES   34 巻 ( 11 ) 頁: 1265-1270   2018年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Web of Science

  22. Yb-doped Fiber Laser Based Coherent Mid-Infrared Frequency Comb at λ = 4.5 μm for CRDS application

    Jin L., Sonnenschein V., Terabayashi R., Hayashi N., Kato S., Yamanaka M., Tomita H., Iguchi T., Sato A., Nozawa K., Yoshida K., Nishizawa N.

    2018 Conference on Lasers and Electro-Optics, CLEO 2018 - Proceedings     2018年8月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:2018 Conference on Lasers and Electro-Optics, CLEO 2018 - Proceedings  

    An offset free mid-infrared optical frequency comb was generated based on an Yb-doped fiber laser system with tunability of 3.9-4.7 μm. Cavity ring down spectroscopy measurement was demonstrated with QCL and MIR comb reference.

    Scopus

  23. A cavity ring-down spectrometer for study of biomedical radiocarbon-labeled samples

    Sonnenschein Volker, Terabayashi Ryohei, Tomita Hideki, Kato Shusuke, Hayashi Noriyoshi, Takeda Shin, Jin Lei, Yamanaka Masahito, Nishizawa Norihiko, Sato Atsushi, Yoshida Kenji, Iguchi Tetsuo

    JOURNAL OF APPLIED PHYSICS   124 巻 ( 3 )   2018年7月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Applied Physics  

    A compact cavity ring-down spectrometer aimed at the detection of trace amounts of radiocarbon (14C) in biomedical samples is demonstrated. Rapid sampling, as required for large scale studies, is made possible by modifications to a CHNS elemental analyzer. After conversion of the carbon content of a sample into CO2, spectral analysis using a high-finesse cavity in conjunction with a quantum cascade laser system reveals the ratio of 14CO2 in relation to the stable isotopologues of 12C and 13C. Cooling and temperature stabilization of the cavity is achieved by a combination of liquid cooling and thermo-electric elements. The system is studied in terms of reproducibility, linearity, and sensitivity as well as contamination and memory effects of the sampling process. While the performance of the system is still limited mainly due to etaloning and other systematic effects, first spectra of biomedical samples, such as urine and feces, have been analyzed at 14C concentration levels above ten times natural abundance. Results are compared with those from a traditional liquid scintillation counter system. Possibilities for improvement of the sensitivity are discussed.

    DOI: 10.1063/1.5041015

    Web of Science

    Scopus

  24. The laser and optical system for the RIBF-PALIS experiment

    Sonoda T., Iimura H., Reponen M., Wada M., Katayama I., Sonnenschein V., Takamatsu T., Tomita H., Kojima T. M.

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   877 巻   頁: 118 - 123   2018年1月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment  

    This paper describes the laser and optical system for the Parasitic radioactive isotope (RI) beam production by Laser Ion-Source (PALIS) in the RIKEN fragment separator facility. This system requires an optical path length of 70 m for transporting the laser beam from the laser light source to the place for resonance ionization. To accomplish this, we designed and implemented a simple optical system consisting of several mirrors equipped with compact stepping motor actuators, lenses, beam spot screens and network cameras. The system enables multi-step laser resonance ionization in the gas cell and gas jet via overlap with a diameter of a few millimeters, between the laser photons and atomic beam. Despite such a long transport distance, we achieved a transport efficiency for the UV laser beam of about 50%. We also confirmed that the position stability of the laser beam stays within a permissible range for dedicated resonance ionization experiments.

    DOI: 10.1016/j.nima.2017.09.055

    Web of Science

    Scopus

  25. 3.1-5.2 mu m Coherent MIR Frequency Comb Based on Yb-Doped Fiber Laser

    Jin Lei, Sonnenschein Volker, Yamanaka Masahito, Tomita Hideki, Iguchi Tetsuo, Sato Atsushi, Nozawa Kohei, Yoshida Kenji, Ninomiya Shin-Ichi, Nishizawa Norihiko

    IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS   24 巻 ( 3 )   2018年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE Journal of Selected Topics in Quantum Electronics  

    An offset-free, wavelength-tunable, and midinfrared frequency comb working at 184 MHz based on difference frequency generation (DFG) in a PPMgSLT crystal was demonstrated. A coherent Raman soliton pulse and Yb-fiber laser output were used as the seed pulses of DFG, and wavelength tunability in the range 3.1-5.2 μ m was realized. A quantum cascade laser stabilized by the absorption line of N2O was used to measure the beat signal with an MIR comb. The MIR comb had a good spatial beam profile, and a high signal-to-noise ratio (SNR) of 70 dB at a wavelength of 4.52 μm was confirmed. A stable and sharp beat signal was observed in the MIR region with a linewidth of 160 kHz, and the SNR was larger than 20 dB.

    DOI: 10.1109/JSTQE.2017.2759258

    Web of Science

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  26. 高感度レーザー分光に基づく生体試料中放射性炭素同位体分析システムの開発

    寺林 稜平, 野沢 耕平, 橋爪 研太, 井口 哲夫, Volker Sonnenschein, 富田 英生, 佐藤 淳史, 林 紀善, 加藤 修介, 金 磊, 山中 真仁, 西澤 典彦

    RADIOISOTOPES   67 巻 ( 3 ) 頁: 85-91   2018年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    <p>医薬品開発プロセスにおいて,放射性炭素(<sup>14</sup>C)標識化合物をヒトに単回投与してヒト薬物動態を評価するマイクロドーズ臨床試験が実用化されつつあり,医薬品開発の低コスト化とリードタイムの大幅短縮が期待されている。本研究では,マイクロドーズ臨床試験における高感度と低コストを兼ね備えた簡便な<sup>14</sup>C測定への適用を念頭に,高感度レーザー分光に基づく生体試料中<sup>14</sup>C分析システムを開発した。</p>

    DOI: 10.3769/radioisotopes.67.85

    CiNii Article

  27. Yb-doped Fiber Laser Based Coherent Mid-Infrared Frequency Comb at lambda=4.5 mu m for CRDS application

    Jin L., Sonnenschein V., Terabayashi R., Hayashi N., Kato S., Yamanaka M., Tomita H., Iguchi T., Sato A., Nozawa K., Yoshida K., Nishizawa N.

    2018 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)     2018年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    Web of Science

  28. Yb-doped fiber laser based coherent mid-infrared frequency comb at λ= 4.5 μm for CRDS application

    Jin L., Sonnenschein V., Terabayashi R., Hayashi N., Kato S., Yamanaka M., Tomita H., Iguchi T., Sato A., Nozawa K., Yoshida K., Nishizawa N.

    Optics InfoBase Conference Papers   Part F94-CLEO_SI 2018 巻   2018年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Optics InfoBase Conference Papers  

    An offset free mid-infrared optical frequency comb was generated based on an Ybdoped fiber laser system with tunability of 3.9-4.7 μm. Cavity ring down spectroscopy measurement was demonstrated with QCL and MIR comb reference.

    DOI: 10.1364/CLEO_SI.2018.STh4K.4

    Scopus

  29. In-gas laser ionization and spectroscopy of actinium isotopes near the N=126 closed shell

    Granados C., Creemers P., Ferrer R., Gaffney L.P., Gins W., De Groote R., Huyse M., Kudryavtsev Y., Martínez Y., Raeder S., Sels S., Van Beveren C., Van Den Bergh P., Van Duppen P., Wrzosek-Lipska K., Zadvornaya A., Barzakh A.E., Bastin B., Delahaye P., Hijazi L., Lecesne N., Luton F., Piot J., Savajols H., Thomas J.C., Traykov E., Beerwerth R., Fritzsche S., Block M., Fléchard X., Franchoo S., Ghys L., Grawe H., Heinke R., Kron T., Naubereit P., Wendt K., Laatiaoui M., Moore I., Sonnenschein V., Loiselet M., Mogilevskiy E., Rothe S.

    Physical Review C   96 巻 ( 5 )   2017年11月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review C  

    The in-gas laser ionization and spectroscopy (IGLIS) technique was applied on the Ac212-215 isotopes, produced at the Leuven Isotope Separator On-Line (LISOL) facility by using the in-gas-cell and the in-gas-jet methods. The first application under on-line conditions of the in-gas-jet laser spectroscopy method showed a superior performance in terms of selectivity, spectral resolution, and efficiency in comparison with the in-gas-cell method. Following the analysis of both experiments, the magnetic-dipole moments for the Ac212-215 isotopes, electric-quadrupole moments and nuclear spins for the Ac214,215 isotopes are presented and discussed. A good agreement is obtained with large-scale nuclear shell-model calculations by using a Pb208 core.

    DOI: 10.1103/PhysRevC.96.054331

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  30. Laser spectroscopy with an electrostatic ConeTrap

    Kelly S., Campbell P., Cheal B., Eronen T., Geldhof S., Jokinen A., Moore I.D., Penttilä H., Pohjalainen I., Rinta-Antila S., Sonnenschein V., Voss A.

    Hyperfine Interactions   238 巻 ( 1 )   2017年11月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Hyperfine Interactions  

    A compact electrostatic trap has been designed and installed as part of the recent upgrades to the IGISOL IV facility. The ConeTrap provides an in vacuo optical pumping site for low energy (800 eV) ionic ensembles available for interaction periods of 10-100 ms. At present, 6.7(3) % of injected mass A=98 ions can be trapped, stored for 5 ms, extracted and transported to a laser-ion interaction region. This fraction represents those ions for which no perturbation to total energy or energy spread is observed. Proposed enhancements to the trap are designed to improve the trapping efficiency by up to a factor of 5. Differential pumping and reduction in background pressure below the present 10−6 mbar will extend storage times beyond 100 ms.

    DOI: 10.1007/s10751-017-1412-z

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  31. Strong γ-ray emission from neutron unbound states populated in β-decay: Impact on (n,γ) cross-section estimates

    Tain J.L., Guadilla V., Valencia E., Algora A., Zakari-Issoufou A.A., Rice S., Meur L.L., Agramunt J., Äystö J., Batist L., Bowry M., Briz J.A., Bui V.M., Caballero-Folch R., Cano-Ott D., Cucoanes A., Elomaa V.V., Eronen T., Estevez E., Estienne M., Fallot M., Farrelly G.F., Fraile L.M., Ganioglu E., Garcia A.R., Gelletly W., Gómez-Hornillos B., Gorelov D., Gorlychev V., Hakala J., Jokinen A., Jordan M.D., Kankainen A., Kolhinen V.S., Kondev F.G., Koponen J., Lebois M., Martínez T., Mason P., Mendoza E., Monserrate M., Montaner-Pizá A., Moore I., Nacher E., Orrigo S.E.A., Penttilä H., Podolyák Z., Pohjalainen I., Porta A., Regan P.H., Reinikainen J., Reponen M., Rinta-Antila S., Rissanen J., Rubio B., Rytkönen K., Shiba T., Sonnenschein V., Sonzogni A.A., Vedia V., Voss A., Wilson J.N.

    EPJ Web of Conferences   146 巻   2017年9月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:EPJ Web of Conferences  

    Total absorption gamma-ray spectroscopy is used to measure accurately the intensity of γ emission from neutron-unbound states populated in the β-decay of delayed-neutron emitters. From the comparison of this intensity with the intensity of neutron emission one can deduce information on the (n,γ) cross section for unstable neutron-rich nuclei of interest in r process abundance calculations. A surprisingly large γ branching was observed for a number of isotopes. The results are compared with Hauser-Feshbach calculations and discussed.

    DOI: 10.1051/epjconf/201714601002

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  32. Total absorption studies of high priority decays for reactor applications: <sup>86</sup>Br and <sup>91</sup>Rb

    Algora A., Rice S., Guadilla V., Tain J.L., Valencia E., Zakari-Issoufou A.A., Agramunt J., Äystö J., Batist L., Briz J.A., Bowry M., Bui V.M., Caballero-Folch R., Cano-Ott D., Cucoanes A., Eronen T., Elomaa V.V., Estevez E., Estienne M., Fallot M., Farrelly G.F., Fraile L.M., Fleming M., Ganioglu E., Garcia A.R., Gelletly W., Gómez-Hornillos B., Gorelov D., Gorlychev V., Hakala J., Jokinen A., Jordan D., Kankainen A., Kolhinen V.S., Kondev F.G., Koponen J., Lebois M., Martinez T., Mason P., Mendoza E., Monserrate M., Montaner-Pizá A., Moore I., Nácher E., Orrigo S.E.A., Penttilä H., Podolyák Z., Pohjalainen I., Porta A., Regan P.H., Reinikainen J., Reponen M., Rinta-Antila S., Rissanen J., Rubio B., Rytkönen K., Shiba T., Sonnenschein V., Sonzogni A.A., Sublet J.C., Vedia V., Voss A., Wilson J.N.

    EPJ Web of Conferences   146 巻   2017年9月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:EPJ Web of Conferences  

    Preliminary results from beta decay studies of nuclei that are important for reactor applications are presented. The beta decays have been studied using the total absorption technique (TAS) and the pure beams provided by the JYFLTRAP system at the IGISOL facility of the University of Jyvaskyla.

    DOI: 10.1051/epjconf/201714610001

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  33. Total absorption spectroscopy of fission fragments relevant for reactor antineutrino spectra

    Fallot M., Porta A., Meur L.L., Briz J.A., Zakari-Issoufou A.A., Guadilla V., Algora A., Taìn J.L., Valencia E., Rice S., Bui V.M., Cormon S., Estienne M., Agramunt J., Äystö J., Batist L., Bowry M., Caballero-Folch R., Cano-Ott D., Cucoanes A., Elomaa V.V., Eronen T., Estévez E., Farrelly G.F., Fraile L.M., Fleming M., Ganogliu E., Garcia A.R., Gelletly W., Gomez-Hornillos M.B., Gorelov D., Gorlychev V., Hakala J., Jokinen A., Jordan M.D., Kankainen A., Karvonen P., Kolhinen V.S., Kondev F.G., Koponen J., Lebois M., Martinez T., Mason P., Mendoza E., Molina F., Monserrate M., Montaner-Pizá A., Moore I., Nácher E., Orrigo S.E.A., Penttilä H., Perez A., Podolyák Z., Pohjalainen I., Regan P.H., Reinikainen J., Reponen M., Rinta-Antila S., Rissanen J., Rubio B., Shiba T., Sonnenschein V., Sonzogni A.A., Sublet J.C., Vedia V., Voss A., Weber C., Wilson J.N.

    EPJ Web of Conferences   146 巻   2017年9月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:EPJ Web of Conferences  

    The accurate determination of reactor antineutrino spectra remains a very active research topic for which new methods of study have emerged in recent years. Indeed, following the long-recognized reactor anomaly (measured antineutrino deficit in short baseline reactor experiments when compared with spectral predictions), the three international reactor neutrino experiments Double Chooz, Daya Bay and Reno have recently demonstrated the existence of spectral distortions in their measurements with respect to the same predictions. These spectral predictions were obtained through the conversion of integral beta-energy spectra obtained at the ILL research reactor. Several studies have shown that the underlying nuclear physics required for the conversion of these spectra into antineutrino spectra is not totally understood. An alternative to such converted spectra is a complementary approach that consists of determining the antineutrino spectrum by means of the measurement and processing of nuclear data. The beta properties of some key fission products suffer from the pandemonium effect which can be circumvented by the use of the Total Absorption Gammaray Spectroscopy technique (TAGS). The two main contributors to the PressurizedWater Reactor antineutrino spectrum in the region where the spectral distortion has been observed are 92Rb and 142Cs, which have been measured at the radioactive beam facility of the University of Jyvaskyla in two TAGS experiments.We present the results of the analysis of the TAGS measurements of the β-decay properties of 92Rb along with preliminary results on 142Cs and report on the measurements already performed.

    DOI: 10.1051/epjconf/201714610002

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  34. TAGS measurements of <sup>100</sup>Nb ground and isomeric states and <sup>140</sup>Cs for neutrino physics with the new DTAS detector

    Guadilla V., Algora A., Tain J.L., Agramunt J., Äystö J., Briz J.A., Cucoanes A., Eronen T., Estienne M., Fallot M., Fraile L.M., Ganioǧlu E., Gelletly W., Gorelov D., Hakala J., Jokinen A., Jordan D., Kankainen A., Kolhinen V., Koponen J., Lebois M., Martinez T., Monserrate M., Montaner-Pizá A., Moore I., Nácher E., Orrigo S.E.A., Penttilä H., Pohjalainen I., Porta A., Reinikainen J., Reponen M., Rinta-Antila S., Rubio B., Rytkönen K., Shiba T., Sonnenschein V., Sonzogni A.A., Valencia E., Vedia V., Voss A., Wilson J.N., Zakari-Issoufou A.A.

    EPJ Web of Conferences   146 巻   2017年9月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:EPJ Web of Conferences  

    In this work we report on total absorption γ-ray spectroscopy measurements of the β decay of fission products that are important contributors to the antineutrino spectrum. The experiment was performed at IGISOL as a part of a campaign of measurements with the new DTAS spectrometer. Preliminary results of the analysis of the β decay of 100Nb,100mNb and 140Cs are presented.

    DOI: 10.1051/epjconf/201714610010

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  35. Characterization of a pulsed injection-locked Ti:sapphire laser and its application to high resolution resonance ionization spectroscopy of copper

    Sonnenschein V., Moore I. D., Raeder S., Reponen M., Tomita H., Wendt K.

    LASER PHYSICS   27 巻 ( 8 )   2017年8月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Laser Physics  

    A high repetition rate pulsed Ti:sapphire laser injection-locked to a continuous wave seed source is presented. A spectral linewidth of 20 MHz at an average output power of 4 W is demonstrated. An enhanced tuning range from 710-920 nm with a single broadband mirror set is realized by the inclusion of a single thin birefringent quartz plate for suppression of unseeded emission. The spectral properties have been analyzed using both a scanning Fabry-Pérot interferometer as well as crossed beam resonance ionization spectroscopy of the hyperfine levels of natural copper. Delayed ionization of the long-lived excited state is demonstrated for increased resolution. For the excited state hyperfine coupling constant of the 244 nm 4s 2S 4s4p4P° ground-state transition in Cu, a factor of ten reduction in error compared to previous literature was achieved. The described laser system has been in operation at several radioactive ion beam facilities.

    DOI: 10.1088/1555-6611/aa7834

    Web of Science

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  36. Experimental study of Tc 100 β decay with total absorption γ -ray spectroscopy

    Guadilla V., Algora A., Tain J.L., Agramunt J., Jordan D., Montaner-Pizá A., Orrigo S.E.A., Rubio B., Valencia E., Suhonen J., Civitarese O., Äystö J., Briz J.A., Cucoanes A., Eronen T., Estienne M., Fallot M., Fraile L.M., Ganioǧlu E., Gelletly W., Gorelov D., Hakala J., Jokinen A., Kankainen A., Kolhinen V., Koponen J., Lebois M., Martinez T., Monserrate M., Moore I., Nácher E., Penttilä H., Pohjalainen I., Porta A., Reinikainen J., Reponen M., Rinta-Antila S., Rytkönen K., Shiba T., Sonnenschein V., Sonzogni A.A., Vedia V., Voss A., Wilson J.N., Zakari-Issoufou A.A.

    Physical Review C   96 巻 ( 1 )   2017年7月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review C  

    The β decay of Tc100 has been studied by using the total absorption γ-ray spectroscopy technique at the Ion Guide Isotope Separator On-Line facility in Jyväskylä. In this work the new Decay Total Absorption γ-ray Spectrometer in coincidence with a cylindrical plastic β detector has been employed. The β intensity to the ground state obtained from the analysis is in good agreement with previous high-resolution measurements. However, differences in the feeding to the first-excited state as well as weak feeding to a new level at high excitation energy have been deduced from this experiment. Theoretical calculations performed in the quasiparticle random-phase approximation framework are also reported. Comparison of these calculations with our measurement serves as a benchmark for calculations of the double β decay of Mo100.

    DOI: 10.1103/PhysRevC.96.014319

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  37. Total absorption spectroscopy study of the β decay of Br 86 and Rb 91

    Rice S., Algora A., Tain J.L., Valencia E., Agramunt J., Rubio B., Gelletly W., Regan P.H., Zakari-Issoufou A.A., Fallot M., Porta A., Rissanen J., Eronen T., Äystö J., Batist L., Bowry M., Bui V.M., Caballero-Folch R., Cano-Ott D., Elomaa V.V., Estevez E., Farrelly G.F., Garcia A.R., Gomez-Hornillos B., Gorlychev V., Hakala J., Jordan M.D., Jokinen A., Kolhinen V.S., Kondev F.G., Martínez T., Mason P., Mendoza E., Moore I., Penttilä H., Podolyák Z., Reponen M., Sonnenschein V., Sonzogni A.A., Sarriguren P.

    Physical Review C   96 巻 ( 1 )   2017年7月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review C  

    The beta decays of Br86 and Rb91 have been studied using the total absorption spectroscopy technique. The radioactive nuclei were produced at the Ion Guide Isotope Separator On-Line facility in Jyväskylä and further purified using the JYFLTRAP. Br86 and Rb91 are considered to be major contributors to the decay heat in reactors. In addition, Rb91 was used as a normalization point in direct measurements of mean gamma energies released in the beta decay of fission products by Rudstam et al. assuming that this decay was well known from high-resolution measurements. Our results show that both decays were suffering from the Pandemonium effect and that the results of Rudstam et al. should be renormalized. The relative impact of the studied decays in the prediction of the decay heat and antineutrino spectrum from reactors has been evaluated.

    DOI: 10.1103/PhysRevC.96.014320

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  38. Characterization of a cylindrical plastic β-detector with Monte Carlo simulations of optical photons

    Guadilla V., Algora A., Tain J.L., Agramunt J., Äystö J., Briz J.A., Cucoanes A., Eronen T., Estienne M., Fallot M., Fraile L.M., Ganioğlu E., Gelletly W., Gorelov D., Hakala J., Jokinen A., Jordan D., Kankainen A., Kolhinen V., Koponen J., Lebois M., Martinez T., Monserrate M., Montaner-Pizá A., Moore I., Nácher E., Orrigo S.E.A., Penttilä H., Pohjalainen I., Porta A., Reinikainen J., Reponen M., Rinta-Antila S., Rubio B., Rytkönen K., Shiba T., Sonnenschein V., Valencia E., Vedia V., Voss A., Wilson J.N., Zakari-Issoufou A.A.

    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment   854 巻   頁: 134 - 138   2017年5月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment  

    In this work we report on the Monte Carlo study performed to understand and reproduce experimental measurements of a new plastic β-detector with cylindrical geometry. Since energy deposition simulations differ from the experimental measurements for such a geometry, we show how the simulation of production and transport of optical photons does allow one to obtain the shapes of the experimental spectra. Moreover, taking into account the computational effort associated with this kind of simulation, we develop a method to convert the simulations of energy deposited into light collected, depending only on the interaction point in the detector. This method represents a useful solution when extensive simulations have to be done, as in the case of the calculation of the response function of the spectrometer in a total absorption γ-ray spectroscopy analysis.

    DOI: 10.1016/j.nima.2017.02.047

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  39. High-resolution laser spectroscopy of long-lived plutonium isotopes

    Voss A., Sonnenschein V., Campbell P., Cheal B., Kron T., Moore I. D., Pohjalainen I., Raeder S., Trautmann N., Wendt K.

    PHYSICAL REVIEW A   95 巻 ( 3 )   2017年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review A  

    Long-lived isotopes of plutonium were studied using two complementary techniques, high-resolution resonance ionization spectroscopy (HR-RIS) and collinear laser spectroscopy (CLS). Isotope shifts have been measured on the 5f67s27F0→5f56d27s(J=1) and 5f67s27F1→5f67s7p(J=2) atomic transitions using the HR-RIS method and the hyperfine factors have been extracted for the odd mass nuclei Pu239,241. CLS was performed on the 5f67s8F1/2→J=1/2(27523.61cm-1) ionic transition with the hyperfine A factors measured for Pu239. Changes in mean-squared charge radii have been extracted and show a good agreement with previous nonoptical methods, with an uncertainty improvement by approximately one order of magnitude. Plutonium represents the heaviest element studied to date using collinear laser spectroscopy.

    DOI: 10.1103/PhysRevA.95.032506

    Web of Science

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  40. Efficient, high-resolution resonance laser ionization spectroscopy using weak transitions to long-lived excited states

    De Groote R., Verlinde M., Sonnenschein V., Flanagan K., Moore I., Neyens G.

    Physical Review A   95 巻 ( 3 )   2017年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review A  

    Laser spectroscopic studies on minute samples of exotic radioactive nuclei require very efficient experimental techniques. In addition, high resolving powers are required to allow extraction of nuclear structure information. Here we demonstrate that by using weak atomic transitions, resonance laser ionization spectroscopy is achieved with the required high efficiency (1%-10%) and precision (linewidths of tens of MHz). We illustrate experimentally and through the use of simulations how the narrow experimental linewidths are achieved and how distorted resonance ionization spectroscopy line shapes can be avoided. The role of the delay of the ionization laser pulse with respect to the excitation laser pulse is crucial: the use of a delayed ionization step permits the best resolving powers and line shapes. A high efficiency is maintained if the intermediate level has a lifetime that is at least of the order of the excitation laser pulse width. A model that describes this process reproduces well the observed features and will help to optimize the conditions for future experiments. The simulation code is available upon request to the authors.

    DOI: 10.1103/PhysRevA.95.032502

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  41. Study of the β decay of fission products with the dtas detector

    Guadilla V., Algora A., Tain J.L., Agramunt J., Äystö J., Briz J.A., Cucoanes A., Eronen T., Estienne M., Fallot M., Fraile L.M., Ganioglu E., Gelletly W., Gorelov D., Hakala J., Jokinen A., Jordan D., Kankainen A., Kolhinen V., Koponen J., Lebois M., Martinez T., Monserrate M., Montaner-Pizá A., Moore I., Nácher E., Orrigo S.E.A., Penttilä H., Pohjalainen I., Porta A., Reinikainen J., Reponen M., Rinta-Antila S., Rubio B., Rytkönen K., Shiba T., Sonnenschein V., Sonzogni A.A., Valencia E., Vedia V., Voss A., Wilson J.N., Zakari-Issoufou A.A.

    Acta Physica Polonica B   48 巻 ( 3 ) 頁: 529 - 532   2017年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Acta Physica Polonica B  

    Total Absorption Spectroscopy measurements of the β decay of 103Mo and 103Tc, important contributors to the decay heat summation calculation in reactors, are reported in this work. The analysis of the experiment, performed at IGISOL with the new DTAS detector, show new β intensity that was not detected in previous measurements with Ge detectors.

    DOI: 10.5506/APhysPolB.48.529

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  42. Towards high-resolution laser ionization spectroscopy of the heaviest elements in supersonic gas jet expansion

    Ferrer R., Barzakh A., Bastin B., Beerwerth R., Block M., Creemers P., Grawe H., De Groote R., Delahaye P., Fléchard X., Franchoo S., Fritzsche S., Gaffney L.P., Ghys L., Gins W., Granados C., Heinke R., Hijazi L., Huyse M., Kron T., Kudryavtsev Y., Laatiaoui M., Lecesne N., Loiselet M., Lutton F., Moore I.D., Martínez Y., Mogilevskiy E., Naubereit P., Piot J., Raeder S., Rothe S., Savajols H., Sels S., Sonnenschein V., Thomas J.C., Traykov E., Van Beveren C., Van Den Bergh P., Van Duppen P., Wendt K., Zadvornaya A.

    Nature Communications   8 巻   2017年2月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nature Communications  

    Resonant laser ionization and spectroscopy are widely used techniques at radioactive ion beam facilities to produce pure beams of exotic nuclei and measure the shape, size, spin and electromagnetic multipole moments of these nuclei. However, in such measurements it is difficult to combine a high efficiency with a high spectral resolution. Here we demonstrate the on-line application of atomic laser ionization spectroscopy in a supersonic gas jet, a technique suited for high-precision studies of the ground- and isomeric-state properties of nuclei located at the extremes of stability. The technique is characterized in a measurement on actinium isotopes around the N=126 neutron shell closure. A significant improvement in the spectral resolution by more than one order of magnitude is achieved in these experiments without loss in efficiency.

    DOI: 10.1038/ncomms14520

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  43. Total absorption γ -ray spectroscopy of the β -delayed neutron emitters Br 87, Br 88, and Rb 94

    Valencia E., Tain J.L., Algora A., Agramunt J., Estevez E., Jordan M.D., Rubio B., Rice S., Regan P., Gelletly W., Podolyák Z., Bowry M., Mason P., Farrelly G.F., Zakari-Issoufou A., Fallot M., Porta A., Bui V.M., Rissanen J., Eronen T., Moore I., Penttilä H., Äystö J., Elomaa V.V., Hakala J., Jokinen A., Kolhinen V.S., Reponen M., Sonnenschein V., Cano-Ott D., Garcia A.R., Martínez T., Mendoza E., Caballero-Folch R., Gomez-Hornillos B., Gorlichev V., Kondev F.G., Sonzogni A.A., Batist L.

    Physical Review C   95 巻 ( 2 )   2017年2月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review C  

    We investigate the decay of Br87,88 and Rb94 using total absorption γ-ray spectroscopy. These important fission products are β-delayed neutron emitters. Our data show considerable βγ intensity, so far unobserved in high-resolution γ-ray spectroscopy, from states at high excitation energy. We also find significant differences with the β intensity that can be deduced from existing measurements of the β spectrum. We evaluate the impact of the present data on reactor decay heat using summation calculations. Although the effect is relatively small it helps to reduce the discrepancy between calculations and integral measurements of the photon component for U235 fission at cooling times in the range 1-100 s. We also use summation calculations to evaluate the impact of present data on reactor antineutrino spectra. We find a significant effect at antineutrino energies in the range of 5 to 9 MeV. In addition, we observe an unexpected strong probability for γ emission from neutron unbound states populated in the daughter nucleus. The γ branching is compared to Hauser-Feshbach calculations, which allow one to explain the large value for bromine isotopes as due to nuclear structure. However the branching for Rb94, although much smaller, hints of the need to increase the radiative width Γγ by one order of magnitude. This increase in Γγ would lead to a similar increase in the calculated (n,γ) cross section for this very neutron-rich nucleus with a potential impact on r process abundance calculations.

    DOI: 10.1103/PhysRevC.95.024320

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  44. Highly coherent tunable mid-infrared frequency comb pumped by supercontinuum at 1 mu m

    Jin Lei, Yamanaka Masahito, Sonnenschein Volker, Tomita Hideki, Iguchi Tetsuo, Sato Atsushi, Oh-hara Toshinari, Nishizawa Norihiko

    APPLIED PHYSICS EXPRESS   10 巻 ( 1 )   2017年1月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Applied Physics Express  

    We report a tunable mid-infrared frequency comb working at 184 MHz, which is based on difference frequency generation in a periodically poled Mg-doped stoichiometric lithium tantalate (PPMgSLT) crystal pumped by high-power supercontinuum pulses. Supercontinuum pulses from two fibers with different dispersion properties were examined. With a photonic crystal fiber (PCF) having normal dispersion properties, a tunable wavelength range of 2.9-4.7μm was achieved. With another PCF having zero dispersion at 1040 nm, a maximum power of 1.34mW was observed at 3.9 μm. The high coherence of the pulses generated with this scheme was verified experimentally, and a fringe visibility of 0.90 was observed.

    DOI: 10.7567/APEX.10.012503

    Web of Science

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  45. 4.4-5.2 mu m Wavelength Tunable, Coherent MIR Frequency Comb Generation Based on Yb-doped Fiber Laser

    Jin Lei, Yamanaka Masahito, Sonnenschein Volker, Tomita Hideki, Iguchi Tetsuo, Sato Atsushi, Ideno Akira, Oh-hara Toshinari, Nishizawa Norihiko

    2017 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)     頁: .   2017年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Web of Science

  46. Coherent mid-infrared optical frequency comb working at 4.52 μm based on Yb-doped fiber laser

    Jin L., Sonnenschein V., Yamanaka M., Tomita H., Iguchi T., Sato A., Ideno A., Oh-hara T., Nishizawa N.

    Optics InfoBase Conference Papers   Part F75-ASSL 2017 巻   2017年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Optics InfoBase Conference Papers  

    Offset free mid-infrared optical frequency comb at 4.52 μm was generated through DFG pumped by Yb-doped fiber laser system. Narrow RF beat between MIR comb and quantum cascade laser was observed with high SNR.

    DOI: 10.1364/ASSL.2017.AW1A.2

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  47. Optical feedback in dfb quantum cascade laser for mid-infrared cavity ring-down spectroscopy

    Terabayashi Ryohei, Sonnenschein Volker, Tomita Hideki, Hayashi Noriyoshi, Kato Shusuke, Jin Lei, Yamanaka Masahito, Nishizawa Norihiko, Sato Atsushi, Nozawa Kohei, Hashizume Kenta, Oh-Hara Toshinari, Iguchi Tetsuo

    HYPERFINE INTERACTIONS   238 巻 ( 1 )   2016年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Hyperfine Interactions  

    A simple external optical feedback system has been applied to a distributed feedback quantum cascade laser (DFB QCL) for cavity ring-down spectroscopy (CRDS) and a clear effect of feedback was observed. A long external feedback path length of up to 4m can decrease the QCL linewidth to around 50kHz, which is of the order of the transmission linewidth of our high finesse ring-down cavity. The power spectral density of the transmission signal from high finesse cavity reveals that the noise at frequencies above 20kHz is reduced dramatically.

    DOI: 10.1007/s10751-016-1390-6

    Web of Science

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  48. Development of a saturated absorption spectroscopy setup at IGISOL for characterisation of Fabry-Perot interferometers

    Geldhof S., El Youbi S., Moore I. D., Pohjalainen I., Sonnenschein V., Terabayashi R., Voss A.

    HYPERFINE INTERACTIONS   238 巻 ( 1 )   2016年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Hyperfine Interactions  

    A saturated absorption spectroscopy setup was developed and optimised for the characterisation of a home-built and a commercial Fabry-Pérot interferometer (FPI). The free spectral range of these FPIs has been determined with reliable statistical and systematic errors. These FPIs will be used for accurate wavelength determination of broad- and narrowband pulsed Ti:sapphire lasers used in resonance ionisation spectroscopy experiments.

    DOI: 10.1007/s10751-016-1385-3

    Web of Science

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  49. Developments towards in-gas-jet laser spectroscopy studies of actinium isotopes at LISOL

    Raeder S., Bastin B., Block M., Creemers P., Delahaye P., Ferrer R., Fléchard X., Franchoo S., Ghys L., Gaffney L.P., Granados C., Heinke R., Hijazi L., Huyse M., Kron T., Kudryavtsev Y., Laatiaoui M., Lecesne N., Luton F., Moore I.D., Martinez Y., Mogilevskiy E., Naubereit P., Piot J., Rothe S., Savajols H., Sels S., Sonnenschein V., Traykov E., Van Beveren C., Van Den Bergh P., Van Duppen P., Wendt K., Zadvornaya A.

    Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms   376 巻   頁: 382 - 387   2016年6月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms  

    To study exotic nuclides at the borders of stability with laser ionization and spectroscopy techniques, highest efficiencies in combination with a high spectral resolution are required. These usually opposing requirements are reconciled by applying the in-gas-laser ionization and spectroscopy (IGLIS) technique in the supersonic gas jet produced by a de Laval nozzle installed at the exit of the stopping gas cell. Carrying out laser ionization in the low-temperature and low density supersonic gas jet eliminates pressure broadening, which will significantly improve the spectral resolution. This article presents the required modifications at the Leuven Isotope Separator On-Line (LISOL) facility that are needed for the first on-line studies of in-gas-jet laser spectroscopy. Different geometries for the gas outlet and extraction ion guides have been tested for their performance regarding the acceptance of laser ionized species as well as for their differential pumping capacities. The specifications and performance of the temporarily installed high repetition rate laser system, including a narrow bandwidth injection-locked Ti:sapphire laser, are discussed and first preliminary results on neutron-deficient actinium isotopes are presented indicating the high capability of this novel technique.

    DOI: 10.1016/j.nimb.2015.12.014

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  50. In-gas-cell laser ionization studies of plutonium isotopes at IGISOL

    Pohjalainen I., Moore I. D., Kron T., Raeder S., Sonnenschein V., Tomita H., Trautmann N., Voss A., Wendt K.

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS   376 巻   頁: 233 - 239   2016年6月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms  

    In-gas-cell resonance laser ionization has been performed on long-lived isotopes of Pu at the IGISOL facility, Jyväskylä. This initiates a new programme of research towards high-resolution optical spectroscopy of heavy actinide elements which can be produced in sufficient quantities at research reactors and transported to facilities elsewhere. In this work a new gas cell has been constructed for fast extraction of laser-ionized elements. Samples of 238-240,242Pu and 244Pu have been evaporated from Ta filaments, laser ionized, mass separated and delivered to the collinear laser spectroscopy station. Here we report on the performance of the gas cell through studies of the mass spectra obtained in helium and argon, before and after the radiofrequency quadrupole cooler-buncher. This provides valuable insight into the gas phase chemistry exhibited by Pu, which has been additionally supported by measurements of ion time profiles. The resulting monoatomic yields are sufficient for collinear laser spectroscopy. A gamma-ray spectroscopic analysis of the Pu samples shows a good agreement with the assay provided by the Mainz Nuclear Chemistry department.

    DOI: 10.1016/j.nimb.2016.02.019

    Web of Science

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  51. First experiment with the NUSTAR/FAIR Decay Total Absorption γ-Ray Spectrometer (DTAS) at the IGISOL IV facility

    Guadilla V., Algora A., Tain J.L., Agramunt J., Äystö J., Briz J.A., Cano-Ott D., Cucoanes A., Eronen T., Estienne M., Fallot M., Fraile L.M., Ganioglu E., Gelletly W., Gorelov D., Hakala J., Jokinen A., Jordan D., Kankainen A., Kolhinen V., Koponen J., Lebois M., Martinez T., Monserrate M., Montaner-Pizá A., Moore I., Nácher E., Orrigo S., Penttilä H., Podolyak Z., Pohjalainen I., Porta A., Regan P., Reinikainen J., Reponen M., Rinta-Antila S., Rubio B., Rytkönen K., Shiba T., Sonnenschein V., Sonzogni A.A., Valencia E., Vedia V., Voss A., Wilson J.N., Zakari-Issoufou A.A.

    Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms   376 巻   頁: 334 - 337   2016年6月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms  

    The new Decay Total Absorption Spectrometer (DTAS) has been commissioned with low energy radioactive beams at the upgraded IGISOL IV facility. The DTAS is a segmented detector composed of up to 18 NaI(Tl) crystals and it will be a key instrument in the DESPEC experiment at FAIR. In this document we report on the experimental setup and the first measurements performed with DTAS at IGISOL. The detector was characterized by means of MC simulations, and this allowed us to calculate the response function of the spectrometer and analyse the first cases of interest.

    DOI: 10.1016/j.nimb.2015.12.018

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  52. Development of High Resolution Resonance Ionization Mass Spectrometry for Neutron Dosimetry Technique with Nb-93(n, n')Nb-93m Reaction

    Tomita Hideki, Takatsuka Takaaki, Takamatsu Takahide, Adachi Yoshitaka, Furuta Yujin, Noto Takuma, Iguchi Tetsuo, Sonnenschein Volker, Wendt Klaus, Ito Chikara, Maeda Shigetaka

    ISRD 15 - INTERNATIONAL SYMPOSIUM ON REACTOR DOSIMETRY   106 巻   2016年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:EPJ Web of Conferences  

    We have proposed an advanced technique to measure the 93mNb yield precisely by Resonance Ionization Mass Spectrometry, instead of conventional characteristic X-ray spectroscopy. 93mNb-selective resonance ionization is achievable by distinguishing the hyperfine splitting of the atomic energy levels between 93Nb and 93mNb at high resolution. In advance of 93mNb detection, we could successfully demonstrate high resolution resonant ionization spectroscopy of stable 93Nb using an all solid-state, narrow-band and tunable Ti:Sapphire laser system operated at 1 kHz repetition rate.

    DOI: 10.1051/epjconf/201610605002

    Web of Science

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  53. An inductively heated hot cavity catcher laser ion source

    Reponen M., Moore I. D., Pohjalainen I., Rothe S., Savonen M., Sonnenschein V., Voss A.

    REVIEW OF SCIENTIFIC INSTRUMENTS   86 巻 ( 12 )   2015年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Review of Scientific Instruments  

    An inductively heated hot cavity catcher has been constructed for the production of low-energy ion beams of exotic, neutron-deficient Ag isotopes. A proof-of-principle experiment has been realized by implanting primary 107Ag21+ ions from a heavy-ion cyclotron into a graphite catcher. A variable-thickness nickel foil was used to degrade the energy of the primary beam in order to mimic the implantation depth expected from the heavy-ion fusion-evaporation recoils of N = Z 94Ag. Following implantation, the silver atoms diffused out of the graphite and effused into the catcher cavity and transfer tube, where they were resonantly laser ionized using a three-step excitation and ionization scheme. Following mass separation, the ions were identified by scanning the frequency of the first resonant excitation step while recording the ion count rate. Ion release time profiles were measured for different implantation depths and cavity temperatures with the mean delay time varying from 10 to 600 ms. In addition, the diffusion coefficients for silver in graphite were measured for temperatures of 1470 K, 1630 K, and 1720 K, from which an activation energy of 3.2 ± 0.3 eV could be determined.

    DOI: 10.1063/1.4936569

    Web of Science

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  54. Erratum to: “Measuring independent yields of fission products using a penning trap” [Bulletin of the Russian Academy of Sciences: Physics, (2015), 79, (869) DOI 10.3103/S1062873815070114]

    Gorelov D., Eronen T., Hakala J., Jokinen A., Kankainen A., Kolhinen V., Lantz M., Mattera A., Moore I., Penttilä H., Pohjalainen I., Pomp S., Reponen M., Rinta-Antila S., Rubchenya V., Saastamoinen A., Simutkin V., Solders A., Sonnenschein V., Äystö J.

    Bulletin of the Russian Academy of Sciences: Physics   79 巻 ( 10 )   2015年10月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Bulletin of the Russian Academy of Sciences: Physics  

    DOI: 10.3103/S1062873815150010

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  55. Enhanced γ -Ray Emission from Neutron Unbound States Populated in β Decay

    Tain J.L., Valencia E., Algora A., Agramunt J., Rubio B., Rice S., Gelletly W., Regan P., Zakari-Issoufou A.A., Fallot M., Porta A., Rissanen J., Eronen T., Äystö J., Batist L., Bowry M., Bui V.M., Caballero-Folch R., Cano-Ott D., Elomaa V.V., Estevez E., Farrelly G.F., Garcia A.R., Gomez-Hornillos B., Gorlychev V., Hakala J., Jordan M.D., Jokinen A., Kolhinen V.S., Kondev F.G., Martínez T., Mendoza E., Moore I., Penttilä H., Podolyák Z., Reponen M., Sonnenschein V., Sonzogni A.A.

    Physical Review Letters   115 巻 ( 6 )   2015年8月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review Letters  

    Total absorption spectroscopy is used to investigate the β-decay intensity to states above the neutron separation energy followed by γ-ray emission in Br87,88 and Rb94. Accurate results are obtained thanks to a careful control of systematic errors. An unexpectedly large γ intensity is observed in all three cases extending well beyond the excitation energy region where neutron penetration is hindered by low neutron energy. The γ branching as a function of excitation energy is compared to Hauser-Feshbach model calculations. For Br87 and Br88 the γ branching reaches 57% and 20%, respectively, and could be explained as a nuclear structure effect. Some of the states populated in the daughter can only decay through the emission of a large orbital angular momentum neutron with a strongly reduced barrier penetrability. In the case of neutron-rich Rb94 the observed 4.5% branching is much larger than the calculations performed with standard nuclear statistical model parameters, even after proper correction for fluctuation effects on individual transition widths. The difference can be reconciled by introducing an enhancement of 1 order of magnitude in the photon strength to neutron strength ratio. An increase in the photon strength function of such magnitude for very neutron-rich nuclei, if it proves to be correct, leads to a similar increase in the (n,γ) cross section that would have an impact on r process abundance calculations.

    DOI: 10.1103/PhysRevLett.115.062502

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  56. Measuring independent yields of fission products using a penning trap

    Gorelov D., Eronen T., Hakala J., Jokinen A., Kankainen A., Kolhinen V., Lantz M., Mattera A., Moore I., Penttilä H., Pohjalainen I., Pomp S., Reponen M., Rinta-Antila S., Rubchenya V., Saastamoinen A., Simutkin V., Solders A., Sonnenschein V., Äystö J.

    Bulletin of the Russian Academy of Sciences: Physics   79 巻 ( 7 ) 頁: 869 - 871   2015年7月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Bulletin of the Russian Academy of Sciences: Physics  

    A new method for determining independent fission products is used in an experiment at the Accelerator Laboratory of the University of Jyväskylä. The method combines the chemical universality of the ion guide technique and the unique properties of the Penning trap. A beam of charged particles is formed by stopping fission products in gaseous helium. The Penning trap is employed as a highly accurate filter to identify particles by their mass. The yields of fission products are determined by the ion count downstream of the trap. The setup’s mass resolving power is on the order of 105 with a radio frequency excitation time of 400 ms. Such high mass resolution occasionally allows us not only to separate nuclides but to separate the isomeric and ground states of nuclei as well. Independent yields of fission products are measured in the fission reaction of the 232Th isotope by protons with an energy of 25 MeV. A short description of the method ae nd soexperimental data are supplememnted by the results fro theoretical calculations.

    DOI: 10.3103/S1062873815070114

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  57. 27pSH-11 A narrowband injection-locked Titanium : Sapphire laser system for precision laser resonance ionization spectroscopy at the SLOWRIPALIS-facility

    Reponen M., Sonoda T., Wada M., Sonnenschein V., Tomita H.

      70 巻 ( 0 )   2015年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.11316/jpsgaiyo.70.2.0_321

    CiNii Article

  58. Characterization of a dual-etalon Ti:Sapphire laser via resonance ionization spectroscopy of stable copper isotopes

    Sonnenschein V., Moore I., Khan H., Pohjalainen I., Reponen M.

    Hyperfine Interactions   227 巻 ( 1-3 ) 頁: 113 - 123   2014年6月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Hyperfine Interactions  

    Resonance ionization spectroscopy (RIS) inside a buffer gas-filled ion guide is a very sensitive tool for a first determination of nuclear moments and charge radii of radioactive isotopes produced using the IGISOL technique. Currently employed pulsed Ti:sapphire laser systems have a typical laser linewidth of 5 GHz in the fundamental, which in many cases is the dominant line broadening effect. We present results of RIS on stable 63,65Cu using a dual-etalon Ti:sapphire laser with a reduced linewidth of 1 GHz. Determination of hyperfine parameters of 63Cu revealed discrepancies when compared to existing higher resolution data. A study of systematic uncertainties is underway using a homemade scanning Fabry-Pérot interferometer (FPI). A real-time recording of the mode structure of the multi-longitudinal mode Ti:sapphire laser during a scan of the 244.238 nm atomic ground state transition in parallel with the readout from the commercial wavemeter has identified sources of uncertainty. © 2014 Springer Science+Business Media Dordrecht.

    DOI: 10.1007/s10751-013-1000-9

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  59. Total Absorption Study of Beta Decays Relevant for Nuclear Applications and Nuclear Structure

    Algora A., Valencia E., Taín J.L., Jordan M.D., Agramunt J., Rubio B., Estevez E., Molina F., Montaner A., Guadilla V., Fallot M., Porta A., Zakari-Issoufou A.A., Bui V.M., Rice S., Podolyák Z., Regan P.H., Gelletly W., Bowry M., Mason P., Farrelly G.F., Rissanen J., Eronen T., Moore I., Penttilä H., Äystö J., Eloma V., Hakala J., Jokinen A., Kolkinen V., Reponen M., Sonnenschein V., Cano-Ott D., Martínez T., Mendoza E., Garcia A.R., Gomez-Hornillos M.B., Gorlychev V., Caballero-Folch R., Kondev F.G., Sonzogni A.A.

    Nuclear Data Sheets   120 巻   頁: 12 - 15   2014年6月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Data Sheets  

    An overview is given of our activities related to the study of the beta decay of neutron rich nuclei relevant for nuclear applications. Recent results of the study of the beta decay of 87,88Br using a new segmented total absorption spectrometer are presented. The measurements were performed at the IGISOL facility using trap-assisted total absorption spectroscopy. © 2014 Elsevier Inc..

    DOI: 10.1016/j.nds.2014.06.129

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  60. Laser spectroscopy at IGISOL IV

    Dicker A.R., Campbell P., Cheal B., Gorelov D., Hakala J., Johnson D.J.S., Jokinen A., Kolhinen V., Koponen J., Moore I.D., Penttilä H., Pohjalainen I., Reponen M., Rinta-Antila S., Sonnenschein V., Voss A.

    Hyperfine Interactions   227 巻 ( 1-3 ) 頁: 139 - 145   2014年6月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Hyperfine Interactions  

    The IGISOL (Ion Guide Isotope Separator On-Line) facility at the University of Jyväskylä accelerator laboratory has been upgraded and relocated to a purpose built laboratory. The new laboratory includes a dedicated MCC30 proton/deuteron cyclotron, which in conjunction with beams from the K130 cyclotron, will greatly increase the beam time available at the facility. Full off-line commissioning of the laser spectroscopy beam-line was achieved in February 2013 and on-line commissioning with radioactive beams was achieved in May 2013. Optical hyperfine resonance spectra were obtained for previously studied radioactive molybdenum isotopes and used to investigate our long term stability, efficiency and ability to successfully reproduce previous results from IGISOL III. A preliminary spectrum for the previously unmeasurable 107Mo was collected, displaying the improved capabilities of the new facility. Both data-sets show that the laser-line is ready for future experiments. The IGISOL IV beams are cleaner and have a higher radioactive content compared to similar experiments at IGISOL III. © 2014 Springer Science+Business Media Dordrecht.

    DOI: 10.1007/s10751-013-0997-0

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  61. Coulomb displacement energies as a probe for nucleon pairing in the f7/2 shell

    Kankainen A., Eronen T., Gorelov D., Hakala J., Jokinen A., Kolhinen V., Reponen M., Rissanen J., Saastamoinen A., Sonnenschein V., Äystö J.

    Physical Review C - Nuclear Physics   89 巻 ( 5 )   2014年5月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review C - Nuclear Physics  

    Coulomb displacement energies of T=1/2 mirror nuclei have been studied via a series of high-precision QEC-value measurements with the double Penning trap mass spectrometer JYFLTRAP. Most recently, the QEC values of the f7/2-shell mirror nuclei V45 (QEC=7123.82(22) keV) and Mn49 (QEC=7712.42(24) keV) have been measured with unprecedented precision. The data reveal a 16-keV (1.6σ) offset in the adopted Atomic Mass Evaluation 2012 value of Mn49, suggesting the need for further measurements to verify whether there is a breakdown of the quadratic form of the isobaric multiplet mass equation in the fp shell. Precisely measured QEC values confirm that the pairing effect in the Coulomb energies is quenched when entering the f7/2 shell and reaches a minimum in the midshell. © 2014 American Physical Society.

    DOI: 10.1103/PhysRevC.89.051302

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  62. Isomeric yield ratios of fission products measured with the jyfltrap

    Gorelov D., Hakala J., Jokinen A., Kolhinen V., Koponen J., Moore I., Penttilä H., Pohjalainen I., Reponen M., Rinta-Antila S., Sonnenschein V., Voss A., Al-Adili A., Lantz M., Mattera A., Pomp S., Rakopoulos V., Simutkin V., Solders A., Äystö J.

    Acta Physica Polonica B   45 巻 ( 2 ) 頁: 211 - 216   2014年2月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Acta Physica Polonica B  

    Experimental methods to determine isomeric yield ratios usually apply -spectroscopic techniques. In such methods, ground and isomeric statesare distinguished by their decays. In the present work, several isomeric yield ratios of fission products have been measured by utilizing capabilities of the double Penning-trap mass spectrometer JYFLTRAP, where isomeric and ground state were separated by their masses. To verify the new experimental technique, the results were compared to those from -spectroscopy measurements.

    DOI: 10.5506/APhysPolB.45.211

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  63. Development of resonance ionization in a supersonic gas-jet for studies of short-lived and long-lived radioactive nuclei

    Takatsuka Takaaki, Tomita Hideki, Sonnenschein Volker, Sonoda Tetsu, Adachi Yoshitaka, Sakamoto Chika, Mita Hiroki, Noto Takuma, Ito Chikara, Maeda Shigetaka, Iguchi Tetsuo, Wada Michiharu, Wendt Klaus, Moore Iain

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS   317 巻 ( PART B ) 頁: 586 - 589   2013年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms  

    High-resolution resonance ionization spectroscopy (RIS) is required for laser spectroscopy and trace analysis of short-lived and long-lived radioactive nuclei. We have proposed high-resolution resonance ionization spectroscopy in a gas jet combined with a narrow band-width injection-locked Ti:Sapphire laser. Resonance ionization of stable 93Nb in a gas jet was demonstrated using a broad bandwidth Ti:Sapphire laser. In addition, a setup for high-resolution RIS in a gas-jet was designed using numerical simulations of the gas-jet conditions based on computational fluid dynamics.© 2013 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.nimb.2013.05.054

    Web of Science

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  64. Towards commissioning the new IGISOL-4 facility

    Moore I., Eronen T., Gorelov D., Hakala J., Jokinen A., Kankainen A., Kolhinen V., Koponen J., Penttilä H., Pohjalainen I., Reponen M., Rissanen J., Saastamoinen A., Rinta-Antila S., Sonnenschein V., Äystö J.

    Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms   317 巻 ( PART B ) 頁: 208 - 213   2013年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms  

    The Ion Guide Isotope Separator On-Line facility at the Accelerator Laboratory of the University of Jyväskylä is currently being re-commissioned as IGISOL-4 in a new experimental hall. Access to intense beams of protons and deuterons from a new MCC30/15 cyclotron, with continued possibility to deliver heavy-ion beams from the K = 130 MeV cyclotron, offers extensive opportunities for long periods of fundamental experimental research, developments and applications. A new layout of beam lines with a considerable increase in floor space offers new modes of operation at the facility, as well as a possibility to incorporate more complex detector setups. We present a general overview of IGISOL-4 and the current status of several projects, including the collinear laser spectroscopy station and the future of neutron-induced fission. Recent milestones from the first commissioning experiments are presented.© 2013 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.nimb.2013.06.036

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  65. The FURIOS laser ion source at IGISOL-4

    Reponen M., Moore I., Pohjalainen I., Sonnenschein V., Jokinen A.

    Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms   317 巻 ( PART B ) 頁: 422 - 425   2013年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms  

    The FURIOS laser ion source at the Accelerator Laboratory of the University of Jyväskylä has been moved to a new location as a part of the IGISOL-4 facility. The laser ion source project had a high priority which allowed the transport of laser light to be optimized during the design phase. The laser resonators have been upgraded with a dual etalon configuration leading to greatly reduced laser linewidth. The transport efficiency of the dual-chamber gas cell has been determined using an alpha recoil source, with efficiencies ranging from a few percent in the beam interaction chamber to nearly 20% in the ionization chamber. In addition, we present recent results from the re-commissioning of the laser system on stable copper isotopes. © 2013 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.nimb.2013.05.061

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  66. Recommissioning of JYFLTRAP at the new IGISOL-4 facility

    Kolhinen V.S., Eronen T., Gorelov D., Hakala J., Jokinen A., Jokiranta K., Kankainen A., Koikkalainen M., Koponen J., Kulmala H., Lantz M., Mattera A., Moore I.D., Penttilä H., Pikkarainen T., Pohjlainen I., Reponen M., Rinta-Antila S., Rissanen J., Rodríguez Triguero C., Rytkönen K., Saastamoinen A., Solders A., Sonnenschein V., Äystö J.

    Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms   317 巻 ( PART B ) 頁: 506 - 509   2013年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms  

    The JYFLTRAP double Penning-trap system was moved to a new location along with the Ion Guide Isotope Separator On-line (IGISOL) facility at the Accelerator Laboratory of the University of Jyväskylä. The move made it possible to upgrade various parts of the facility. For example, separate beam lines for JYFLTRAP and the collinear laser spectroscopy station were constructed after the radio-frequency quadrupole cooler and buncher. In this contribution we give an overview of the new JYFLTRAP facility and results from the first stable ion-beam tests.© 2013 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.nimb.2013.07.050

    Scopus

  67. Development of high resolution resonance ionization mass spectrometry for trace analysis of Nb-93m

    Takatsuka Takaaki, Tomita Hideki, Sonoda Tetsu, Sonnenschein Volker, Sakamoto Chika, Mita Hiroki, Noto Takuma, Ito Chikara, Maeda Shigetaka, Iguchi Tetsuo, Wada Michiharu, Wendt Klaus, Moore Iain

    HYPERFINE INTERACTIONS   216 巻 ( 1-3 ) 頁: 41 - 46   2013年4月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Hyperfine Interactions  

    93Nb(n, n′)93mNb reaction allows retrospective estimation of integrated fast neutron dose in nuclear reactor. We proposed isomer-selective trace analysis of 93mNb by Resonance Ionization Mass Spectrometry (RIMS) combined with a gas-jet atomic source and an injection locked Ti:Sapphire laser system operated at several kHz. Resonant ionization spectroscopy of Nb in gas-jet using Ti:Sapphire laser was demonstrated. © 2013 Springer Science+Business Media Dordrecht.

    DOI: 10.1007/s10751-013-0824-7

    Web of Science

    Scopus

  68. Isotope-selective laser photodetachment for I-129 accelerator mass spectrometry

    Takahashi Tone, Tomita Hideki, Nakayama Motoi, Adachi Yoshitaka, Sonnenschein Volker, Iguchi Tetsuo, Wendt Klaus

    HYPERFINE INTERACTIONS   216 巻 ( 1-3 ) 頁: 133 - 138   2013年4月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Hyperfine Interactions  

    A pulsed injection-locked Ti:Sapphire laser and a negative ion laser ablation source are developed for compact accelerator mass spectrometry assisted by isotope-selective laser photodetachment. An output of about 60 mW at a repetition rate of 1 kHz is available using intracavity second-harmonic generation with a bandwidth of 20 MHz. A negative iodine ion pulse with a width of 100 ns is obtained by laser ablation of a NH4I sample. The negative ion source and the injection-locked Ti:Sapphire laser are suitable for trace analysis of 129I. © 2013 Springer Science+Business Media Dordrecht.

    DOI: 10.1007/s10751-013-0766-0

    Web of Science

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  69. Control of RILIS lasers at IGISOL facilities using a compact atomic beam reference cell

    Kron T., Ferrer-Garcia R., Lecesne N., Sonnenschein V., Raeder S., Rossnagel J., Wendt K.

    Hyperfine Interactions   216 巻 ( 1-3 ) 頁: 53 - 58   2013年4月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Hyperfine Interactions  

    The choice and proper operation of the laser systems for laser ion sources at on-line facilities using multi-step resonance ionization processes is the basis for production of intense and pure radioactive ion beams. These pave the way for numerous fundamental studies in nuclear and astrophysics. A comparison between systems of medium or high repetition rate pulsed tunable lasers based on dyes or crystals as active medium has been carried out at the IGISOL facility at Louvain-la-Neuve. The importance of properly controlling the operation conditions of the individual lasers via a reference atomic beam chamber is highlighted and design and implementation of such a compact device for permanent monitoring as well as possible regulation of the various laser parameters of relevance is discussed. © 2013 Springer Science+Business Media Dordrecht.

    DOI: 10.1007/s10751-012-0756-7

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  70. Isomeric states close to doubly magic 132Sn studied with the double Penning trap JYFLTRAP

    Kankainen A., Hakala J., Eronen T., Gorelov D., Jokinen A., Kolhinen V., Moore I., Penttilä H., Rinta-Antila S., Rissanen J., Saastamoinen A., Sonnenschein V., Äystö J.

    Physical Review C - Nuclear Physics   87 巻 ( 2 )   2013年2月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review C - Nuclear Physics  

    The double Penning trap mass spectrometer JYFLTRAP has been employed to measure masses and excitation energies for 11/2- isomers in 121Cd, 123Cd, 125Cd, and 133Te, for 1/2- isomers in 129In and 131In, and for 7- isomers in 130Sn and 134Sb. These first direct mass measurements of the Cd and In isomers reveal deviations to the excitation energies based on results from β-decay experiments and yield new information on neutron- and proton-hole states close to 132Sn. A new excitation energy of 144(4) keV has been determined for 123Cdm. A good agreement with the precisely known excitation energies of 121Cdm, 130Snm, and 134Sbm has been found. © 2013 American Physical Society.

    DOI: 10.1103/PhysRevC.87.024307

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  71. Recent mass measurements for the r process at JYFLTRAP

    Kankainen A., Eronen T., Gorelov D., Hakala J., Jokinen A., Kolhinen V., Moore I., Penttilä H., Rinta-Antila S., Rissanen J., Saastamoinen A., Sonnenschein V., Äystö J.

    Proceedings of Science     2012年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Proceedings of Science  

    This contribution gives an overview of recent mass measurements performed in the 132Sn region relevant for the r-process studies. The atomic masses of 121-128Cd, 129,131In, 130-135Sn, 131-136Sb, and 132-140Te have been measured with the JYFLTRAP double Penning trap mass spectrometer. Among these, the masses of four r-process nuclei - 135Sn, 136Sb, 139Te, and 140Te - have been experimentally determined for the first time. In addition, the masses of the (11/2-) isomers in 121,123,125Cd and 133Te, (1/2-) isomers in 129,131In, and (7-) isomers in 130Sn and 134Sb have been measured and corresponding excitation energies have been determined. The ground-state mass values have been compared to recent Atomic Mass Evaluations and deviations have been found in particular for the states based on beta-decay energies. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.

    Scopus

  72. Performance of a high repetition pulse rate laser system for in-gas-jet laser ionization studies with the Leuven laser ion source @ LISOL

    Ferrer R., Sonnenschein V., Bastin B., Franchoo S., Huyse M., Kudryavtsev Y., Kron T., Lecesne N., Moore I., Osmond B., Pauwels D., Radulov D., Raeder S., Rens L., Reponen M., Roßnagel J., Savajols H., Sonoda T., Thomas J., Van Den Bergh P., Van Duppen P., Wendt K., Zemlyanoy S.

    Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms   291 巻   頁: 29 - 37   2012年11月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms  

    The laser ionization efficiency of the Leuven gas cell-based laser ion source was investigated under on- and off-line conditions using two distinctly different laser setups: a low-repetition rate dye laser system and a high-repetition rate Ti:sapphire laser system. A systematic study of the ion signal dependence on repetition rate and laser pulse energy was performed in off-line tests using stable cobalt and copper isotopes. These studies also included in-gas-jet laser spectroscopy measurements on the hyperfine structure of 63Cu. A final run under on-line conditions in which the radioactive isotope 59Cu (T 1/2 = 81.5 s) was produced, showed a comparable yield of the two laser systems for in-gas-cell ionization. However, a significantly improved time overlap by using the high-repetition rate laser system for in-gas-jet ionization was demonstrated by an increase of the overall duty cycle, and at the same time, pointed to the need for a better shaped atomic jet to reach higher ionization efficiencies. © 2012 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.nimb.2012.08.023

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  73. Determination of the ground-state hyperfine structure in neutral <sup>229</sup>Th

    Sonnenschein V., Raeder S., Hakimi A., Moore D., Wendt K.

    Journal of Physics B: Atomic, Molecular and Optical Physics   45 巻 ( 16 )   2012年8月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Physics B: Atomic, Molecular and Optical Physics  

    The ground-state hyperfine structure of neutral 229Th has been measured for the first time using high-resolution resonance ionization spectroscopy. The measurements were performed as a preparatory work aimed at the identification of the predicted low-lying 7.6eV isomer in 229Th through an investigation of its hyperfine structure. The hyperfine coupling constants have been extracted for the atomic ground state as well as for three excited states at 26096, 26113 and 38278cm 1. Due to rather small splittings not all hyperfine components were completely resolved and therefore an extensive χ 2-error analysis was performed to achieve reliable results. The ground-state transition to the excited state at 38278cm 1 was identified to be the most sensitive of the three transitions with regard to the future identification of the isomeric state. © 2012 IOP Publishing Ltd.

    DOI: 10.1088/0953-4075/45/16/165005

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  74. Precision mass measurements beyond Sn132: Anomalous behavior of odd-even staggering of binding energies

    Hakala J., Dobaczewski J., Gorelov D., Eronen T., Jokinen A., Kankainen A., Kolhinen V.S., Kortelainen M., Moore I.D., Penttilä H., Rinta-Antila S., Rissanen J., Saastamoinen A., Sonnenschein V., Ystö J.

    Physical Review Letters   109 巻 ( 3 )   2012年7月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review Letters  

    Atomic masses of the neutron-rich isotopes Cd121-128, In129,131, Sn130-135, Sb131-136, and Te132-140 have been measured with high precision (10ppb) using the Penning-trap mass spectrometer JYFLTRAP. Among these, the masses of four r-process nuclei Sn135, Sb136, and Te139,140 were measured for the first time. An empirical neutron pairing gap expressed as the odd-even staggering of isotopic masses shows a strong quenching across N=82 for Sn, with a Z dependence that is unexplainable by the current theoretical models. © 2012 American Physical Society.

    DOI: 10.1103/PhysRevLett.109.032501

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  75. Determination of the ground state hyperfine structure in neutral 229Th 査読有り

    V. Sonnenschein, S. Raeder, A. Hakimi, I.D. Moore, K. Wendt

    J. Phys. B: At. Mol. Opt. Phys.   45 巻   頁: 165005   2012年7月

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    担当区分:筆頭著者   記述言語:英語   掲載種別:研究論文(学術雑誌)  

  76. Laser developments and resonance ionization spectroscopy at IGISOL

    Reponen M., Moore I., Kessler T., Pohjalainen I., Rothe S., Sonnenschein V.

    European Physical Journal A   48 巻 ( 4 ) 頁: 1 - 15   2012年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:European Physical Journal A  

    We present an overview of recent laser ion source developments at the IGISOL facility, Jyväskylä. Technological advances in the lasers have led to a considerable increase in second-harmonic laser power with the use of intra-cavity second-harmonic generation, as well as to narrow linewidth capability by applying an injection-locking technique to a Ti:sapphire laser. The use of a diffraction grating for frequency selection in a new laser resonator has dramatically improved the wide-range tunability of the laser system, resulting in an ideal tool for the development of new ionization schemes. The role of different laser bandwidths, laser intensity and environmental broadening mechanisms on the experimental width of the measured spectral line have been studied using bismuth, silver and nickel, in the gas cell and expanding gas jet. Applications of novel ion guide nozzle design has led to remarkably collimated gas jets which overcome the current limitations in the gas cell-based laser ion source trap (LIST) method. Detailed planning is under way to optimize the new laser laboratory and laser transport path in order to fully exploit the unique opportunities afforded by the new IGISOL-4 facility. © 2012 SIF, Springer-Verlag Berlin Heidelberg.

    DOI: 10.1140/epja/i2012-12045-2

    Scopus

  77. The search for the existence of <sup>229m</sup>Th at IGISOL

    Sonnenschein V., Moore I., Raeder S., Hakimi A., Popov A., Wendt K.

    European Physical Journal A   48 巻 ( 4 ) 頁: 1 - 15   2012年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:European Physical Journal A  

    An overview of preparatory work aiming at the identification of the low-lying 7.6 eV isomer in 229Th through a measurement of its hyperfine structure is presented. A 233U recoil gas cell has been developed and has undergone several iterations in order to improve the efficiency of extracting a low-energy beam of 229Th+ ions. Spectroscopic studies on stable 232Th have been carried out to establish an efficient laser ionization scheme. The latter will be applied in connection with the gas cell in order to improve the extraction efficiency by accessing the neutral atomic fraction. In addition to that of the 229Th ground state, the hyperfine structure of the isomer can then be determined either by collinear laser spectroscopy on the extracted and accelerated ions or by direct in-source/in-jet high-resolution Resonance Ionization Spectroscopy (RIS). The first experiments using high-resolution RIS have been performed and isotope shifts of 228Th, 229Th and 230Th relative to 232Th were measured on an atomic 7s2 → 7s7p ground-state transition at 380.42 nm. A template of the ground-state hyperfine structure of 229Th has been established for a 261.24nm UV transition. This is an important step towards identification of the isomeric state. © 2012 SIF, Springer-Verlag Berlin Heidelberg.

    DOI: 10.1140/epja/i2012-12052-3

    Scopus

  78. 中性子ドシメトリに向けたガスジェットレーザー共鳴イオン化質量分析に基づく<SUP>93m</SUP>Nb微量分析法の開発:(1)チタンサファイアレーザーを用いたNb共鳴イオン化実験

    坂本 知佳, 前田 茂貴, 井口 哲夫, 和田 道治, Klaus Wendt, Iain Moore, 高塚 卓旦, Volker Sonnenschein, 富田 英生, 園田 哲, 三田 浩希, 能任 琢真, 足立 義貴, 伊藤 主税

    日本原子力学会 年会・大会予稿集   2012 巻 ( 0 )   2012年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:一般社団法人 日本原子力学会  

    中性子ドシメトリは原子炉安全性評価のために極めて重要であり、多重放射化箔法による評価を行っている。なかでも<SUP>93</SUP>Nbと中性子との非弾性散乱により核異性体<SUP>93m</SUP>Nbを生成する反応を利用したNbドシメータは、0.1MeV以上の長期積算中性子線量評価がほぼ唯一可能なドシメータとして着目されている。しかし従来法の軟X線スペクトロスコピーに基づく核反応率の測定では、測定確度が不十分であるといった問題がある。そこで本研究では、ガスジェット原子源と注入同期チタンサファイアレーザーを組み合わせた共鳴イオン化質量分析法に基づく<SUP>93m</SUP>Nb微量分析法の開発を進めている。今回は真空中および低真空下においてチタンサファイアレーザーを用いたNb共鳴イオン化実験を行い、共鳴ピーク線幅の評価等を行った。その結果、最小で8GHzを得た

    DOI: 10.11561/aesj.2012f.0.92.0

    CiNii Article

  79. 中性子ドシメトリに向けたガスジェットレーザー共鳴イオン化質量分析に基づく<SUP>93m</SUP>Nb微量分析法の開発:(2)<SUP>93m</SUP>Nb微量分析のためのガスジェット原子源の開発

    高塚 卓旦, 前田 茂貴, 井口 哲夫, 和田 道治, Klaus Wendt, Iain Moore, 坂本 知佳, Volker Sonnenschein, 富田 英生, 園田 哲, 三田 浩希, 能任 琢真, 足立 義貴, 伊藤 主税

    日本原子力学会 年会・大会予稿集   2012 巻 ( 0 )   2012年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:一般社団法人 日本原子力学会  

    共鳴イオン化質量分析に基づく<SUP>93m</SUP>Nb微量分析を行うためには、高い核異性体選択性が求められるため、狭帯域波長可変レーザーの適用とドップラー拡がりの抑制が必要である。本研究では、ドップラー拡がりの抑制のためのガスジェット原子源と狭帯域波長可変レーザーである注入同期チタンサファイアレーザーによる共鳴イオン化を組み合わせたガスジェットレーザー共鳴イオン化質量分析法を開発している。今回はプロトタイプガスジェト原子源における共鳴イオン化実験を行い、ガスジェット中でのNb共鳴イオン化に成功した。さらに熱流体数値計算に基づくガスジェット原子源の最適条件の検討を行った。

    DOI: 10.11561/aesj.2012f.0.93.0

    CiNii Article

  80. Resonance ionization spectroscopy of thorium isotopes-towards a laser spectroscopic identification of the low-lying 7.6 eV isomer of <sup>229</sup>Th

    Raeder S., Sonnenschein V., Gottwald T., Moore I., Reponen M., Rothe S., Trautmann N., Wendt K.

    Journal of Physics B: Atomic, Molecular and Optical Physics   44 巻 ( 16 )   2011年8月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Physics B: Atomic, Molecular and Optical Physics  

    In-source resonance ionization spectroscopy was used to identify an efficient and selective three-step excitation/ionization scheme of thorium, suitable for titanium:sapphire (Ti:sa) lasers. The measurements were carried out in the preparation of laser spectroscopic investigations for an identification of the low-lying 229mTh isomer predicted at 7.6 0.5 eV above the nuclear ground state. Using a sample of 232Th, a multitude of optical transitions leading to over 20 previously unknown intermediate states of even parity as well as numerous high-lying odd parity auto-ionizing (AI) states were identified. Level energies were determined with an accuracy of 0.06 cm -1 for intermediate and 0.15 cm-1 for AI states. Using different excitation pathways, an assignment of total angular momenta for several energy levels was possible. One particularly efficient ionization scheme of thorium, exhibiting saturation in all three optical transitions, was studied in detail. For all three levels in this scheme, the isotope shifts of the isotopes 228Th, 229Th and 230Th relative to 232Th were measured. An overall efficiency including ionization, transport and detection of 0.6% was determined, which was predominantly limited by the transmission of the mass spectrometer ion optics. © 2011 IOP Publishing Ltd.

    DOI: 10.1088/0953-4075/44/16/165005

    Scopus

  81. The possibilities of the extended IGISOL facility at JYFL

    Penttilä H., Eronen T., Hakala J., Jokinen A., Kankainen A., Karvonen P., Kolhinen V., Moore I., Rissanen J., Reponen M., Saastamoinen A., Sonnenschein V., Äystö J.

    Journal of the Korean Physical Society   59 巻 ( 23 ) 頁: 1589 - 1592   2011年8月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of the Korean Physical Society  

    The IGISOL mass separator facility at the Accelerator Laboratory of the University of Jyväskylä will be moved to a new experimental area next to a new high current MCC30/15 light ion cyclotron. The beam from the JYFL heavy ion K-130 cyclotron can also be directed at the IGISOL target in the new location. This allows doubling the run time of the IGISOL facility to about 4000 hours a year. An extended beam distribution system and a larger floor space will afford more permanent set-ups. Neutron converter target is planned to be utilized in order to study neutron induced fission.

    DOI: 10.3938/jkps.59.1589

    Scopus

  82. High-precision mass measurement of S31 with the double Penning trap JYFLTRAP improves the mass value for Cl32

    Kankainen A., Eronen T., Gorelov D., Hakala J., Jokinen A., Kolhinen V., Reponen M., Rissanen J., Saastamoinen A., Sonnenschein V., Äystö J.

    Physical Review C - Nuclear Physics   82 巻 ( 5 )   2010年11月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review C - Nuclear Physics  

    The mass of S31 has been measured with the JYFLTRAP double Penning trap mass spectrometer. The new mass excess value of -19042.55(24)keV deviates from the adopted value of -19044.6(15)keV by 1.4σ. The mass value of Cl32 has been revised with the new S31 result and the latest data from β-delayed proton decay of Cl32. The new mass excess value for Cl32 is -13334.88(65) keV, which is the most precise value for Cl32 so far and in agreement with the recent (He3,t) data. The isobaric multiplet mass equation has been tested in the T=2 quintet at A=32, and the cubic form of the equation has been found to agree with the experimental data. The QEC value for the β decay of T=1/2 mirror nucleus S31 has been determined as QEC=5397.99(24) keV, which slightly deviates from the previously adopted value. © 2010 The American Physical Society.

    DOI: 10.1103/PhysRevC.82.052501

    Scopus

  83. Production of negative osmium ions by laser desorption and ionization

    Rodríguez D., Sonnenschein V., Blaum K., Block M., Kluge H., Lallena A., Raeder S., Wendt K.

    Review of Scientific Instruments   81 巻 ( 1 )   2010年2月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Review of Scientific Instruments  

    The interest to produce negative osmium ions is manifold in the realm of high-accuracy ion trap experiments: high-resolution nearly Doppler-free laser spectroscopy, antihydrogen formation in its ground state, and contributions to neutrino mass spectrometry. Production of these ions is generally accomplished by sputtering an Os sample with Cs+ ions at tens of keV. Though this is a well-established method commonly used at accelerators, these kind of sources are quite demanding and tricky to operate. Therefore, the development of a more straightforward and cost effective production scheme will be of benefit for ion trap and other experiments. Such a scheme makes use of desorption and ionization with pulsed lasers and identification of the ions by time-of-flight mass spectrometry. First investigations of negative osmium ion production using a pulsed laser for desorption and ionization and a commercial matrix-assisted laser desorption/ionization time-of-flight system for identification has demonstrated the suitability of this technique. More than 103 negative osmium ions per shot were registered after bombarding pure osmium powder with a 5 ns pulse width Nd:yttrium aluminum garnet laser. The limitation in the ion number was imposed by the detection limit of the microchannel plate detector. © 2010 American Institute of Physics.

    DOI: 10.1063/1.3276685

    Scopus

▼全件表示

講演・口頭発表等 9

  1. Yb-doped fiber laser based coherent mid-infrared frequency comb at λ= 4.5 μm for CRDS application

     詳細を見る

    開催年月日: 2018年

    記述言語:英語   会議種別:口頭発表(一般)  

    DOI: 10.1364/CLEO_SI.2018.STh4K.4

    Scopus

  2. 4-5.2 m wavelength tunable, coherent MIR frequency comb generation based on Yb-doped fiber laser

    Jin L.

    2017 Conference on Lasers and Electro-Optics, CLEO 2017 - Proceedings 

     詳細を見る

    開催年月日: 2017年10月

    記述言語:英語   会議種別:口頭発表(一般)  

    DOI: 10.1364/CLEO_SI.2017.STu1K.4

    Scopus

  3. Strong γ-ray emission from neutron unbound states populated in β-decay: Impact on (n,γ) cross-section estimates

     詳細を見る

    開催年月日: 2017年9月

    記述言語:英語   会議種別:口頭発表(一般)  

    DOI: 10.1051/epjconf/201714601002

    Scopus

  4. TAGS measurements of <sup>100</sup>Nb ground and isomeric states and <sup>140</sup>Cs for neutrino physics with the new DTAS detector

    Guadilla V.

    EPJ Web of Conferences 

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    開催年月日: 2017年9月

    記述言語:英語   会議種別:口頭発表(一般)  

    DOI: 10.1051/epjconf/201714610010

    Scopus

  5. Total absorption studies of high priority decays for reactor applications: <sup>86</sup>Br and <sup>91</sup>Rb

    Algora A.

    EPJ Web of Conferences 

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    開催年月日: 2017年9月

    記述言語:英語   会議種別:口頭発表(一般)  

    DOI: 10.1051/epjconf/201714610001

    Scopus

  6. Total absorption spectroscopy of fission fragments relevant for reactor antineutrino spectra

    Fallot M.

    EPJ Web of Conferences 

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    開催年月日: 2017年9月

    記述言語:英語   会議種別:口頭発表(一般)  

    DOI: 10.1051/epjconf/201714610002

    Scopus

  7. Study of the β decay of fission products with the dtas detector

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    開催年月日: 2017年3月

    記述言語:英語   会議種別:口頭発表(一般)  

    DOI: 10.5506/APhysPolB.48.529

    Scopus

  8. Coherent mid-infrared optical frequency comb working at 4.52 μm based on Yb-doped fiber laser

     詳細を見る

    開催年月日: 2017年

    記述言語:英語   会議種別:口頭発表(一般)  

    DOI: 10.1364/ASSL.2017.AW1A.2

    Scopus

  9. Recent mass measurements for the r process at JYFLTRAP

    Kankainen A.

    Proceedings of Science 

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    開催年月日: 2012年12月

    記述言語:英語   会議種別:口頭発表(一般)  

    Scopus

▼全件表示

科研費 1

  1. 生体内代謝物解析のためのレーザー分光に基づく放射性炭素同位体分析法の開発

    研究課題/研究課題番号:18H03469  2018年4月 - 2021年3月

    科学研究費助成事業  基盤研究(B)

    富田 英生, 古川 高子, 山本 誠一, 寺林 稜平, SONNENSCH Volker

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    担当区分:研究分担者 

 

担当経験のある科目 (本学) 3

  1. Mathematics II and Tutorial

    2021

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    Supervision of self-study mathematics exercises and explanation of solutions as well as correcting and grading of homework problems

  2. Mathematics II and Tutorial

    2019

  3. 放射線計測A

    2017

 

学術貢献活動 1

  1. Guest editor of Special issue of Applied Sciences Journal 国際学術貢献

    役割:監修

    MDPI journals  2021年6月 - 2022年4月