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

担当区分：筆頭著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：International Union of Crystallography (IUCr)  

Neutron polarization analysis (NPA) for small-angle neutron scattering (SANS) experiments using a pulsed neutron source was successfully achieved by applying a ³He spin filter as a spin analyzer for the neutrons scattered from the sample. The cell of the ³He spin filter gives a weak small-angle scattering intensity (background) and covers a sufficient solid angle for performing SANS experiments. The relaxation time of the ³He polarization is sufficient for continuous use for approximately 2 days, thus reaching the typical duration required for a complete set of SANS experiments. Although accurate evaluation of the incoherent neutron scattering, which is predominantly attributable to the extremely large incoherent scattering cross section of hydrogen atoms in samples, is difficult using calculations based on the sample elemental composition, the developed NPA approach with consideration of the influence of multiple neutron scattering enabled reliable decomposition of the SANS intensity distribution into the coherent and incoherent scattering components. To date, NPA has not been well established as a standard technique for SANS experiments at pulsed neutron sources such as the Japan Proton Accelerator Research Complex (J-PARC) and the US Spallation Neutron Source. It is anticipated that this work will contribute significantly to the accurate determination of the coherent neutron scattering component for scatterers in various types of organic sample systems in SANS experiments at J-PARC, particularly for systems involving competition between the coherent and incoherent scattering intensity.

DOI： 10.1107/s1600576721001643

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）   出版者・発行元：Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment  

We are developing a neutron polarizer with polarized 3He gas, referred to as a 3He spin filter, based on the Spin Exchange Optical Pumping (SEOP) for polarized neutron scattering experiments at Materials and Life Science Experimental Facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC). A 3He gas-filling station was constructed at J-PARC, and several 3He cells with long spin relaxation times have been fabricated using the gas-filling station. A laboratory has been prepared in the MLF beam hall for polarizing 3He cells, and compact pumping systems with laser powers of 30 W and 110 W, which can be installed onto a neutron beamline, have been developed. A 3He polarization of 85% was achieved at a neutron beamline by using the pumping system with the 110 W laser. Recently, the first user experiment utilizing the 3He spin filter was conducted, and there have been several more since then. The development and utilization of 3He spin filters at MLF of J-PARC are reported.

DOI： 10.1016/j.nima.2020.164301

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

An sp-mixing model, which describes a compound nuclear reaction by mixing partial waves, predicts a correlation term in this reaction. A detailed study of the sp-mixing model is required to study the feasibility of a new type of time reversal symmetry violation search experiment. The correlation term σn·(kn×kγ) in the La139(n - ,γ) reaction has been studied by measuring γ-ray and neutron energies utilizing epithermal polarized neutrons and germanium detectors. The transverse asymmetry for single γ-ray transition was measured to be 0.60±0.19 in the p-wave resonance.

DOI： 10.1103/PhysRevC.101.064624

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その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevC.101.064624/fulltext

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

J-GLOBAL

掲載種別：研究論文（学術雑誌）   出版者・発行元：Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics  

We present a search for possible spin dependent interactions of the neutron<br />
with matter through exchange of spin 1 bosons with axial vector couplings as<br />
envisioned in possible extensions of the Standard Model. This was sought using<br />
a slow neutron polarimeter that passed transversely polarized slow neutrons by<br />
unpolarized slabs of material arranged so that this interaction would tilt the<br />
plane of polarization and develop a component along the neutron momentum. The<br />
result for the rotation angle, $\phi&#039;_{V_5} =<br />
[2.8\pm\,4.6(stat.)\pm\,4.0(sys.)]\times 10^{-5}~\mbox{rad/m}$ is consistent<br />
with zero. This result improves the upper bounds on the neutron-matter coupling<br />
$g_{A}^{2}$ from such an interaction by about three orders of magnitude for<br />
force ranges in the mm-$\mu$m regime.

DOI： 10.1016/j.physletb.2018.06.066

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arXiv

担当区分：筆頭著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Physical Review C  

Angular distribution of individual $\gamma$-rays, emitted from a<br />
neutron-induced compound nuclear state via radiative capture reaction of<br />
${}^{139}$La(n,$\gamma$) has been studied as a function of incident neutron<br />
energy in the epithermal region by using germanium detectors.<br />
An asymmetry $A_{\mathrm{LH } }$ was defined as $(N_{\mathrm L}-N_{\mathrm<br />
H})/(N_{\mathrm L}+N_{\mathrm H})$, where $N_{\mathrm L}$ and $N_{\mathrm H}$<br />
are integrals of low and high energy region of a neutron resonance<br />
respectively, and we found that $A_{\mathrm{LH } }$ has the angular dependence of<br />
$(A\cos\theta_\gamma+B)$, where $\theta_\gamma$ is emitted angle of<br />
$\gamma$-rays, with $A= -0.3881\pm0.0236$ and $B=-0.0747\pm0.0105$ in 0.74 eV<br />
p-wave resonance.<br />
This angular distribution was analyzed within the framework of interference<br />
between s- and p-wave amplitudes in the entrance channel to the compound<br />
nuclear state, and it is interpreted as the value of the partial p-wave neutron<br />
width corresponding to the total angular momentum of the incident neutron<br />
combined with the weak matrix element, in the context of the mechanism of<br />
enhanced parity-violating effects. Additionally we used the result to quantify<br />
the possible enhancement of the breaking of the time-reversal invariance in the<br />
vicinity of the p-wave resonance.

DOI： 10.1103/PhysRevC.97.034622

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arXiv

掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Instrumentation  

In this study, the germanium detector assembly, installed at the Accurate Neutron-Nuclear Reaction measurement Instruments (ANNRI) in the Material and Life Science Facility (MLF) operated by the Japan Proton Accelerator Research Complex (J-PARC), has been characterized for extension to the measurement of the angular distribution of individual γ-ray transitions from neutron-induced compound states. We have developed a Monte Carlo simulation code using the GEANT4 toolkit, which can reproduce the pulse-height spectra of γ-rays from radioactive sources and (n,γ) reactions. The simulation is applicable to the measurement of γ-rays in the energy region of 0.5-11.0 MeV.

DOI： 10.1088/1748-0221/13/02/P02018

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arXiv

掲載種別：研究論文（学術雑誌）   出版者・発行元：Progress of Theoretical and Experimental Physics  

To solve the "neutron lifetime puzzle,"where measured neutron lifetimes differ depending on the measurement methods, an experiment with a pulsed neutron beam at J-PARC is in progress. In this experiment, neutrons are bunched into 40-cm lengths using a spin flip chopper (SFC), where the statistical sensitivity was limited by the aperture size of the SFC. The SFC comprises three sets of magnetic supermirrors and two resonant spin flippers. In this paper, we discuss an upgrade to enlarge the apertures of the SFC. With this upgrade, the statistics per unit time of the neutron lifetime experiment increased by a factor of 2.8, while maintaining a signal-to-noise ratio of 250-400, which is comparable to the previous one. Consequently, the time r equir ed to r each a pr ecision of 1 s in the neutron lifetime ex- periment was reduced from 590 to 170 days, which is a significant reduction in time. This improvement in the statistics will also contribute to the reduction of systematic uncertain- ties, such as background evaluation, fostering further advancements in the neutron lifetime experiments at J-PARC.

DOI： 10.1093/ptep/ptae123

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その他リンク： https://academic.oup.com/ptep/article-pdf/2024/9/093G01/59179657/ptae123.pdf

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

Measurements of circular polarization of γ-ray emitted from neutron capture reactions provide valuable information for nuclear physics studies. The spin and parity of excited states can be determined by measuring the circular polarization from polarized neutron capture reactions. Furthermore, the γ-ray circular polarization in a neutron capture resonance is crucial for studying the enhancement effect of parity nonconservation in compound nuclei. The γ-ray circular polarization can be measured using a polarimeter based on magnetic Compton scattering. A polarimeter was constructed, and its performance indicators were evaluated using a circularly polarized γ-ray beam. Finally, as a demonstration, the γ-ray circular polarization was measured in 32S(n,γ)33S reactions with polarized neutrons.

DOI： 10.1140/epja/s10050-024-01392-6

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その他リンク： https://link.springer.com/article/10.1140/epja/s10050-024-01392-6/fulltext.html

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  

We have developed instruments for magnetic neutron holography (MNH) using polarized white neutrons to investigate the local magnetic structures of magnetic alloys. We chose the 3He spin filter method as the neutron polarizer to polarize neutrons over a wide wavelength range of up to a few 100 meV. We developed a magnet device to saturate the magnetizations of ferromagnetic samples, and instruments to transport polarized neutrons from a 3He spin filter to the MNH sample. The neutron polarization, Pn, at the beginning of the MNH experiments was confirmed to be 0.46, which is feasible for MNH. Using the developed instruments, we obtained preliminary results for the room-temperature ferromagnetic alloy Fe0.08Co0.92. Technical problems encountered in the experiments and ways to overcome them are discussed. Based on these results, we believe that MNH that use polarized neutrons is promising.

DOI： 10.1016/j.nima.2024.169349

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Physics (Switzerland)  

The mass  (Formula presented.)  of the negative muon is one of the parameters of the elementary particle Standard Model and it allows us to verify the CPT (charge–parity–time) symmetry theorem by comparing  (Formula presented.)  value with the mass  (Formula presented.)  of the positive muon. However, the experimental determination precision of  (Formula presented.)  is  (Formula presented.), which is an order of magnitude lower than the determination precision of  (Formula presented.)  at  (Formula presented.). The authors aim to determine  (Formula presented.)  and the magnetic moment  (Formula presented.)  with a precision of  (Formula presented.)  through spectroscopy of the hyperfine structure (HFS) of muonic helium-4 atom  (Formula presented.)  under high magnetic fields.  (Formula presented.)  is an exotic atom where one of the two electrons of the  (Formula presented.)  atom is replaced by a negative muon. To achieve the goal, it is necessary to determine the HFS of  (Formula presented.)  with a precision of  (Formula presented.). This paper describes the determination procedure of the HFS of  (Formula presented.)  in weak magnetic fields reported recently, and the work towards achieving the goal of higher precision measurement.

DOI： 10.3390/physics6020054

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Interactions  

Muonic He (μHe) is a hydrogen-like atom composed of a helium atom with one of its electrons replaced by a negative muon. Measurements of the ground-state hyperfine structure (HFS) interval of the μHe atom is a sensitive tool to test the three-body atomic system, bound-state quantum electrodynamics (QED) theory, and determine fundamental constants of the negative muon magnetic moment and mass. It allows a test of the CPT theorem in muons by comparing these constants with positive muons. Precise measurements of the ground-state HFS interval using a microwave magnetic resonance technique are now in progress at J-PARC by the MuSEUM collaboration. Furthermore, a new experimental approach to recover the muon polarization lost during the muon cascade process is being investigated by repolarizing μHe atoms using a spin-exchange optical pumping (SEOP) technique. The first laser repolarization experiment was recently performed. An overview of the different features of these new μHe atom HFS measurements and the latest results are presented.

DOI： 10.1007/s10751-024-01912-2

Scopus

その他リンク： https://link.springer.com/article/10.1007/s10751-024-01912-2/fulltext.html

出版者・発行元：Physical Review C  

Neutron transmission experiments can offer a new type of highly sensitive search for time-reversal invariance violating (TRIV) effects in nucleon-nucleon interactions via the same enhancement mechanism observed for large parity violating (PV) effects in neutron-induced compound nuclear processes. In these compound processes, the TRIV cross section is given as the product of the PV cross section, a spin factor κ, and a ratio of TRIV and PV matrix elements. We determined κ to be 0.59±0.05 for La139+n using both (n,γ) spectroscopy and (n→ +139La→) transmission. This result quantifies for the first time the high sensitivity of the La139 0.75-eV p-wave resonance in a future search for effects of P-odd/T-odd interactions in (n→ +139La→) forward transmission.

DOI： 10.1103/PhysRevC.109.L041602

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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：Journal of Chemical Physics  

The small-angle neutron scattering (SANS) and small-angle x-ray scattering (SAXS) measurements were performed for deuterated and non-deuterated poly(ethylene glycol) (d-PEG and h-PEG, respectively) in D2O and a D2O/H2O mixed solvent (Mix) to compare the scattering profiles. To determine the coherent scattering intensity of SANS, a 3He spin filter was utilized. The scattering profiles determined by the SANS measurements were analyzed in terms of the wormlike chain model with touched beads along the contour of the chain. However, the SAXS profiles were not explained by the same model with uniform beads but with beads each consisting of a core and a shell having different electron densities. To explore the chain thickness determined from the SANS profile, the scattering intensities for different combinations of d-PEG/D2O, d-PEG/Mix, h-PEG/D2O, and h-PEG/Mix were also examined.

DOI： 10.1063/5.0192680

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PubMed

掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Journal of the Physical Society of Japan  

DOI： 10.7566/jpscp.41.011005

出版者・発行元：Minerals  

Ultramylonites are among the most extreme fault rocks that commonly occur in the mid-crustal brittle–plastic transition and are mainly characterized by intensely sheared fine-grained microstructures and well-mixed mineral phases. Although the deformation mechanism of ultramylonites is key to understanding the rheological behavior of the mid-crustal shear zone, their microstructural development is still controversial owing to their intensely fine-grained textures. To investigate the possible crustal deformation mechanisms, we studied 13 mylonites obtained from the Kashio shear zone along the Median Tectonic Line that is the largest strike-slip fault in Japan. In particular, we investigated various mixed quartz–plagioclase layers developed within tonalitic mylonite, which are representative of the common mean grain size and crystal fabric of quartz among the studied samples. A high-quality phase-orientation map obtained by electron backscattered diffraction showed not only a wide range of quartz–plagioclase mixing (10%–80% in quartz modal composition) but also revealed a correlation between grain size reduction and crystal fabric weakening in quartz, indicating a change in the deformation mechanism from dislocation creep to grain-size-sensitive creep in the mixed quartz-plagioclase layers. In contrast, plagioclase showed an almost consistent fine grain size and weak to random crystal fabrics regardless of modal composition, indicating that grain size-sensitive creep is dominant. Combined with laboratory-determined flow laws, our results show that the Kashio shear zone could have developed under deformation mechanisms in which the viscosities of quartz and plagioclase are nearly comparable, effectively within 1017–1019 Pa·s, thereby possibly enabling extensive shearing along the Median Tectonic Line.

DOI： 10.3390/min14030229

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出版者・発行元：European Physical Journal A  

Neutron total and capture cross sections of Lanthanum(La)-139 were measured at the Accurate Ne-utron-Nucleus Reaction measurement Instrument (ANNRI) of the Materials and Life Science Experimental Facility (MLF) in the Japan Proton Accelerator Research Complex (J-PARC). The total cross section was deduced from transmission measurement using a Li-glass detector in the energy range from 0.5 to 1500 eV, and the capture cross section was measured by a NaI detector in the energy range from 0.5 to 74 eV. The total cross section was largely different from that in evaluated libraries, such as JENDL-5, in the energy range from 80 to 900 eV. Resonance parameters for four resonances including one negative resonance were obtained using a resonance analysis code, REFIT. The resonance analysis revealed discrepancies in several resonance parameters with the evaluated libraries. Furthermore, the information about the scattering radius was also extracted from the results of the total cross section. The obtained scattering radius was larger than that recorded in the evaluated libraries.

DOI： 10.1140/epja/s10050-023-01203-4

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出版者・発行元：Proceedings of Science  

We are addressing the development of a polarized lanthanum (139La) target by applying a standard dynamic nuclear polarization (DNP) technique to a single crystal of lanthanum aluminate (LaAlO3) doped with neodymium ions (Nd3+), which is very attractive to search for violating effects of the time-reversal invariance with neutrons. The use of the LaAlO3 crystals as target material is very crucial to extend the spin-lattice relaxation time (T1) through the optimization of the Nd3+ concentration. We have almost established a method for precise control of the Nd3+ amount and this method has allowed us to grow the crystal with 0.01 mol% concentration differently from the 0.05 mol% reached before. Simple DNP experiments using a single-shot dewar at 1.3 K and 2.3 T allowed the evaluation of the T1 and the maximum polarization of these crystals. By that we have found that the 0.01 mol% concentration is the best one among the crystals tested in the past. Both, T1 and the maximum polarization of the 0.01 mol% crystal, have not been exactly obtained because of the long relaxation time, Thus, the preparation of a new DNP system is in progress toward DNP experiments for long-term measurement.

Scopus

記述言語：日本語   出版者・発行元：日本中性子科学会  

DOI： 10.5611/hamon.33.2_68

CiNii Research

掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Journal of Physics: Conference Series  

The 3He spin filter has been developed to use pulsed neutrons effectively at J-PARC MLF. In this study, the 3He spin filter was installed in the single crystal neutron diffractometer (BL18 SENJU) at J-PARC MLF as a polarizer of the incident beam, and Half-polarized neutron diffraction experiments were performed. The 3He spin filter was used the "drop-in cell"method with cells that had a relaxation time of 150 hours in the past experiments. The sample was a single crystal of Heusler crystal Cu2MnAl and the sample magnetic field was 0.3 T. The intensities of (111) Bragg peaks of Cu2MnAl were drastically changed with the polarity of the incident neutron beam, and the flipping ratio of 21.7 at 3.6 Å was observed. The experimental setup and the performance of the 3He spin filter used in this experiment are described in detail in this paper.

DOI： 10.1088/1742-6596/2481/1/012005

Scopus

掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Journal of the Physical Society of Japan  

DOI： 10.7566/jpscp.37.021208

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

The neutron energy-dependent angular distribution of γ rays from the Sn117(n,γ) reaction was measured with germanium detectors and a pulsed neutron beam. The angular distribution was clearly observed in γ-ray emissions with an energy of 9327 keV which corresponds to the transition from a neutron resonance of Sn117+n to the ground state of Sn118. The angular distribution causes an angular-dependent asymmetric resonance shape. An asymmetry ALH was defined as (NL-NH)/(NL+NH), where NL and NH are integrated values for lower- and higher-energy regions of a neutron resonance, respectively. We found that the ALH has the angular dependence of (Acosθγ+B), where θγ is the γ-ray emission angle with respect to the incident neutron momentum, with A=0.394±0.073 and B=0.118±0.029 in the 1.33 eV p-wave resonance.

DOI： 10.1103/PhysRevC.105.054615

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記述言語：日本語   出版者・発行元：日本中性子科学会  

DOI： 10.5611/hamon.32.2_76

CiNii Research

掲載種別：研究論文（学術雑誌）   出版者・発行元：EDP Sciences  

The measurement of the ground state hyperfine structure of muonic helium has the potential to improve the precision of the mass of the negative muon by a factor of 50 or more. The mass of the negative muon is very important because it enables us to test the CPT theorem by comparison with positive muon mass. We aim to measure the hyperfine structure of muonic helium with a precision 1000 times higher than previous experiments [1,2] using the highintensity muon beam at J-PARC and have already obtained results better than the current precision in zero-field measurements in a test experiment in March 2021. To further improve the precision, we plan to measure in a high magnetic field and incorporate a technique that can produce highly polarized muonic helium atom [3]. In this paper, we will report on these developments.

DOI： 10.1051/epjconf/202226201012

掲載種別：研究論文（学術雑誌）  

We correct the sign of thetraverse asymmetry ALR in our previous paper The transverse asymmetry is derived from the correlation term snk? , where sn and k? are polarization of incident neutrons and momentum of emitted ? rays, respectively. The neutron polarization direction was determined using two measurements: (1) the measurement of the polarization direction of the circularly polarized laser which is used to polarize the 3He nuclei of the neutron polarizer, and (2) the measurement of the neutron polarization direction as it passes through the 3He neutron polarizer using a magnetic supermirror. However, in (1), the relation between the direction of the circular polarization and the spin of photons was misevaluated. Additionally, in (2), the relation between the neutron polarization direction reflected by the magnetic supermirror and the magnetic field applied to the magnetic supermirror was also misevaluated. Upon reevaluation we have deduced that the neutron polarization direction during the experiment was opposite to what was previously reported, and, hence, the sign of ALR should be reversed. As supporting evidence, the direction of the circular polarization of our laser system was obtained by measuring the electric paramagnetic resonance signal of Rb during laser pumping. The neutron polarization direction was also determined from the measurement of the parity violation at the 0.74-eV p-wave resonance of 139 La + n using our 3He neutron polarizer. These results also support that the neutron polarization direction was opposite to what was previously reported. Consequently, the transverse asymmetries for ? rays emitted in the transition from the 0.74-eV p-wave resonance to the ground state and inclusive ? rays are newly obtained as Agnd LR = - 0.60 ± 0.19 and Ainc LR = - 0.0045 ± 0.0080 , respectively. Similarly, Figs. 9, 11, 13, and 15 in the original paper should be replaced as Figs. 9, 11, 13, and 15 in this Erratum, respectively. The corrections do not affect results and conclusions of the original article. (Figure Presented).

DOI： 10.1103/PhysRevC.105.039901

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CiNii Research

担当区分：筆頭著者   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Journal of the Physical Society of Japan  

DOI： 10.7566/jpscp.33.011121

掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Journal of the Physical Society of Japan  

DOI： 10.7566/jpscp.33.011116

掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Journal of the Physical Society of Japan  

DOI： 10.7566/jpscp.33.011138

掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Journal of the Physical Society of Japan  

DOI： 10.7566/jpscp.33.011137

掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Journal of the Physical Society of Japan  

DOI： 10.7566/jpscp.33.011136

掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Instrumentation  

A neutron lifetime measurement conducted at the Japan Proton Accelerator Research Complex (J-PARC) is counting the number of electrons from neutron decays with a time projection chamber (TPC). The γ rays produced in the TPC cause irreducible background events. To achieve the precise measurement, the inner walls of the TPC consist of 6Li-enriched lithium-fluoride (6LiF) tiles to suppress the amount of γ rays. In order to estimate the amount of γ rays from the 6LiF tile, prompt gamma ray analysis (PGA) measurements were performed using germanium detectors. We reconstructed the measured γ-ray energy spectrum using a Monte Carlo simulation with the stripping method. Comparing the measured spectrum with a simulated one, the number of γ rays emitted from the6LiF tile was (2.3+0.7-0.3) × 10-4 per incident neutron. This is 1.4+0.5-0.2 times the value assumed for a mole fraction of the 6LiF tile. We concluded that the amount of γ rays produced from the 6LiF tile is not more twice the originally assumed value.

DOI： 10.1088/1748-0221/16/02/P02001

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Scopus

担当区分：筆頭著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Pleiades Publishing Ltd  

DOI： 10.1134/s1027451020070356

その他リンク： https://link.springer.com/article/10.1134/S1027451020070356/fulltext.html

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.75.1.0_308

掲載種別：研究論文（国際会議プロシーディングス）  

© Published under licence by IOP Publishing Ltd. A modulated intensity by zero effort (MIEZE) spectrometer is a type of neutron-resonance spin-echo spectrometer and can be used to analyze the slow dynamics of condensed matter by measuring the intermediate scattering function I(Q,τ). A crucial feature of a MIEZE spectrometer is it leaves completely free the space between the sample and the detector because the sample is placed after the neutron-spin analyzer. Measuring the magnetic dynamics with a conventional neutron-spin-echo spectrometer is difficult, but with a MIEZE spectrometer such a measurement may be done simply by introducing a second analyzer after the sample. Measuring the magnetic dynamics with high precision requires the background to be reduced to a minimum and is a job for which a 3He neutron-spin filter (3He-NSF) is a promising candidate as a second analyzer. However, one difficulty with this approach is the diffusion of 3He gas from the 3He-NSF, which may be measured and interpreted as dynamics. Therefore, we investigate herein whether the dynamics of gas diffusion is detected when using a 3He-NSF as second analyzer in a MIEZE spectrometer. Toward this end, we experimented with the MIEZE spectrometer installed at beamline 06 (BL06) at the Materials and Life Science Experimental Facility at Japan Proton Accelerator Research Complex (J-PARC MLF). The results confirm that the gas-diffusion dynamics of the 3He-NSF are not detected, and that the 3He-NSF, therefore, can be used as a second analyzer in this MIEZE spectrometer.

DOI： 10.1088/1742-6596/1316/1/012013

Scopus

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：EDP Sciences  

DOI： 10.1051/epjconf/201921909001

出版者・発行元：Journal of Biorheology  

A cerebral aneurysm is a vascular condition characterized by local ballooning of an artery in the brain. Although aneurysm formation and growth are thought to be the result of destruction of the blood vessel wall, the details of the etiology are unclear. We review the formation and growth of cerebral aneurysms as follows. In the first part, we summarize the history of theories on the pathogenesis of cerebral aneurysm in chronological order from epidemiological and pathological viewpoints and based on data obtained from animal models of experimentally induced cerebral aneurysms, with a focus on the involvement of hemodynamic stress on the arterial wall. In the second part, we review computational fluid dynamics (CFD) studies on the initiation of cerebral aneurysms with a brief overview of the history of CFD in hemodynamics analysis. Of the hypotheses presented, strong emphasis is placed on that of high wall shear stress and a high wall shear stress gradient. Other leading hypotheses involving hemodynamics-related parameters are also reviewed. In the third part, we review CFD studies on the growth of cerebral aneurysms, in which hemodynamic parameters were compared between growing and stable aneurysms, to highlight the hemodynamic characteristics associated with their growth.

DOI： 10.17106/jbr.33.43

Scopus

担当区分：筆頭著者   掲載種別：研究論文（国際会議プロシーディングス）  

© Copyright owned by the author(s). The fundamental parity violation is enhanced by 106 times at maximum in several neutron induced compound nuclei. There is a theoretical prediction that fundamental T-violating effects can be also largely enhanced in compound nuclei implying that T-violation can be searched for by making very sensitive measurements. A T-violation search experiment using compound nuclei is planned at J-PARC. Polarized epithermal neutron beam, polarized nuclear target, and high count rate neutron detector are necessary for the experiment, and therefore a development of the neutron polarizer using polarized 3He is ongoing at J-PARC in JAEA. Recently, a clean vacuum system to fabricate 3He spin filters was constructed, and several 3He spin filters were fabricated. The current status of the development of the 3He spin filter was reported.

Scopus

掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Proceedings of Science  

Large sources of parity violation have been observed in compound nuclear reactions. These enhancements are described by the compound nuclear model, which can be used to describe the angular correlation of γ-rays produced in (n; γ) reactions in medium-heavy nuclei. It has also been suggested that these same reactions could lead to a similar enhancement in time reversal violating processes. Therefore, we are interested in verifying the compound nuclear model by studying the (n; γ) reaction using polarized neutrons. In this paper, we discuss the installation and characterization of a neutron polarizer used in the (n; γ) measurement with transversely polarized neutrons.

DOI： 10.22323/1.356.0042

Scopus

担当区分：筆頭著者   出版者・発行元：Proceedings of Science  

Scopus

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

<jats:p>We performed a polarized neutron transmission asymmetry measurement utilizing the <jats:sup>139</jats:sup>La(<jats:italic>n</jats:italic>,γ)<jats:sup>140</jats:sup>La reaction. This measurement involved the use of a recently developed <jats:sup>3</jats:sup>He spin filter mounted on the J-PARC MLF beam line number 4 (BL04). The resulting value of the longitudinal asymmetry <jats:italic>A</jats:italic><jats:sub><jats:italic>L</jats:italic></jats:sub> = (11.7 ± 1.1)% was found to be in good agreement with existing values in the literature suggesting that the method by which we polarize the neutron beam is not a significant source of uncertainty. This preliminary work represents a first step toward future measurements of the angular correlation in (<jats:italic>n̅</jats:italic>,<jats:italic>Υ</jats:italic>) reactions necessary in the search for enhanced T-Violation in compound nuclei.</jats:p>

DOI： 10.1051/epjconf/201921909002

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.74.1.0_273

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

<jats:p>It is theoretically suggested that the violation of charge conjugation and parity symmetry (CP-violation) could be enhanced in several compound nuclear reactions. According to the CPT theorem the violation of time-reversal symmetry (T-violation) would be enhanced too. The experimental sensitivity to find a T-violating effect in neutron-induced compound nuclear reactions depends on the value of a spin factor κ(<jats:italic>J</jats:italic>), which is a parameter specific for each nuclide. It can be determined from the angular dependence of γ-ray emission in (n,γ) reactions induced near a p-wave resonance. In this paper, the measurement result and the analysis status of experiments using the target nucleus <jats:sup>117</jats:sup>Sn are reported.</jats:p>

DOI： 10.1051/epjconf/201921909004

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）  

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）  

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）  

担当区分：筆頭著者   掲載種別：研究論文（国際会議プロシーディングス）  

担当区分：筆頭著者  

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

<p>ある種の核における中性子共鳴吸収反応では時間反転対称性の破れの効果が増幅される可能性が示唆されている。その核の候補の一つである^139^Laの中性子共鳴吸収反応での増幅の効果を知るために共鳴パラメータを決定する必要がある。本講演では、J-PARCで行った実験のデータを解析した結果を報告する。</p>

DOI： 10.11316/jpsgaiyo.72.1.0_360

CiNii Research

出版者・発行元：一般社団法人 日本物理学会  

<p>我々は原子核の複合核共鳴を用いて、時間反転対称性の破れの探索に取り組んでいる。この実験において必要な統計数の確保のために、1Gcpsの検出計数を持つ中性子検出器が必要となる。しかし現行の検出器では十分とは言えず、高計数率を持つ中性子検出器の開発が必須である。その上で正確な中性子数の把握のために、γ線バックグラウンドの排除も必要となる。当講演では現状の開発の進捗及び今後の展望について報告する。</p>

DOI： 10.11316/jpsgaiyo.72.1.0_356

出版者・発行元：一般社団法人 日本物理学会  

<p>中性子共鳴吸収反応において時間反転対称性の破れが増幅されることが示唆されている。我々はこの探索に向けて候補となる原子核の(n,γ)反応の測定をJ-PARC BL04で進めている。本公演では、Brを使用した実験のデータの解析の結果について発表する。</p>

DOI： 10.11316/jpsgaiyo.72.1.0_302

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.72.2.0_255

CiNii Research

出版者・発行元：一般社団法人 日本物理学会  

<p>中性子吸収反応による複合核共鳴状態では部分波干渉によって対称性の破れが増幅する。時間反転対称性の破れについても電気双極子能率を超えた感度を持つ可能性がある。現在候補となるいくつかの標的核について、増幅度を見積もるための測定を進めている。J-PARCでの実験計画について報告する。</p>

DOI： 10.11316/jpsgaiyo.72.1.0_299

出版者・発行元：一般社団法人 日本物理学会  

<p>中性子共鳴吸収反応による複合核状態では部分波干渉によって空間反転対称性の破れが増幅されることが知られている。時間反転対称性も同様に増幅されることが示唆されている。我々はこの探索に向けて複合核状態での(n,γ)反応測定をJ-PARC BL04で進めている。講演では本実験において必要な中性子偏極デバイスの開発の現状について報告を行う。</p>

DOI： 10.11316/jpsgaiyo.72.1.0_303

担当区分：筆頭著者   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.72.2.0_256

担当区分：筆頭著者   出版者・発行元：一般社団法人 日本物理学会  

<p>中性子共鳴吸収反応において時間反転対称性の破れが増幅されることが示唆されている。我々はこの探索に向けて複合核状態での(n,γ)反応を調査する実験をJ-PARC BL04で進めている。(n,γ)反応におけるγ線の角相関はFlambaumにより予言されているが、詳細な検証は未だ行われていない。本公演では前回公演よりも高精度化したγ線の角相関測定の結果と理論的予測との比較について論じる。</p>

DOI： 10.11316/jpsgaiyo.72.1.0_300

出版者・発行元：Proceedings of Science  

Scopus

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記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.73.2.0_69

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.73.2.0_68

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.73.2.0_67

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.73.2.0_70

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.73.1.0_403

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.73.1.0_404

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.73.1.0_402

J-GLOBAL

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記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.72.2.0_257

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.72.2.0_261

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

&lt;p&gt;中性子吸収反応による複合核共鳴状態では部分波干渉によって対称性の破れが増幅する。時間反転対称性の破れについても電気双極子能率を超えた感度を持つ可能性がある。現在候補となるいくつかの標的核について、増幅度を見積もるための測定を進めている。J-PARCでの実験計画について報告する。&lt;/p&gt;

DOI： 10.11316/jpsgaiyo.72.1.0_299

CiNii Research

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.72.2.0_258

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.72.2.0_259

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

DOI： 10.11316/jpsgaiyo.72.2.0_256

CiNii Research

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

&lt;p&gt;我々は原子核の複合核共鳴を用いて、時間反転対称性の破れの探索に取り組んでいる。この実験において必要な統計数の確保のために、1Gcpsの検出計数を持つ中性子検出器が必要となる。しかし現行の検出器では十分とは言えず、高計数率を持つ中性子検出器の開発が必須である。その上で正確な中性子数の把握のために、γ線バックグラウンドの排除も必要となる。当講演では現状の開発の進捗及び今後の展望について報告する。&lt;/p&gt;

DOI： 10.11316/jpsgaiyo.72.1.0_356

CiNii Research

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

&lt;p&gt;複合核状態を利用したT-violationの研究では、偏極中性子を偏極核標的に入射させる。その際、P-violationやT-violationに無関係なスピンスピン相互作用の影響による中性子スピンの挙動を正しく評価しておくことが、微小なT-violationの探索を実行する上での前提となる。そこで偏極核標的内での中性子偏極度の挙動を考察し、その影響を抑制する方法について議論する。&lt;/p&gt;

DOI： 10.11316/jpsgaiyo.72.1.0_301

J-GLOBAL

記述言語：日本語  

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

&lt;p&gt;中性子共鳴吸収反応による複合核状態では部分波干渉によって空間反転対称性の破れが増幅されることが知られている。時間反転対称性も同様に増幅されることが示唆されている。我々はこの探索に向けて複合核状態での(n,γ)反応測定をJ-PARC BL04で進めている。講演では本実験において必要な中性子偏極デバイスの開発の現状について報告を行う。&lt;/p&gt;

DOI： 10.11316/jpsgaiyo.72.1.0_303

CiNii Research

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

&lt;p&gt;中性子共鳴吸収反応において時間反転対称性の破れが増幅されることが示唆されている。我々はこの探索に向けて候補となる原子核の(n,γ)反応の測定をJ-PARC BL04で進めている。本公演では、Brを使用した実験のデータの解析の結果について発表する。&lt;/p&gt;

DOI： 10.11316/jpsgaiyo.72.1.0_302

CiNii Research

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

&lt;p&gt;中性子共鳴吸収反応において時間反転対称性の破れが増幅されることが示唆されている。我々はこの探索に向けて複合核状態での(n,γ)反応を調査する実験をJ-PARC BL04で進めている。(n,γ)反応におけるγ線の角相関はFlambaumにより予言されているが、詳細な検証は未だ行われていない。本公演では前回公演よりも高精度化したγ線の角相関測定の結果と理論的予測との比較について論じる。&lt;/p&gt;

DOI： 10.11316/jpsgaiyo.72.1.0_300

CiNii Research

J-GLOBAL

出版者・発行元：Proceedings of Science  

© Copyright owned by the author(s). Large enhanced P violation in a nuclear resonance reaction has been observed by using a polarized neutron beam. Enhanced CP violation is predicted to exist within the same nuclear reaction. We are now preparing to supply a polarized neutron beam for a CP violation search experiment. In the enhancement process of CP violation, we assume that the P violation of the compound nuclear state doesn&#039;t depend on the final state. However this assumption has not been verified yet. We plan to verify the assumption by measuring the 139La(n,g ) reaction with a polarized neutron beam at J-PARC MLF BL04. The supplied neutron beam will be polarized by using 3He spin filter, which will be installed into BL04. We present the states of development for 3He spin filter and study of the equipment in BL04.

Scopus

記述言語：日本語  

J-GLOBAL

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

&lt;p&gt;中性子寿命はCKM行列のVud項及びビッグバン元素合成論において重要なパラメータであり、これまで2手法で測定されてきた。しかし、両者の測定結果には8.4秒の乖離があり、異なる手法での測定が必要となる。本実験は検出器内で生じた中性子の崩壊を電子によって同定する。しかし、中性子捕獲反応由来のガンマ線が電子を発生させることがあり、これは背景事象となる。この背景事象を理解するためにJ−PARC/MLF/BL04で検出器と同素材の試料の中性子照射試験を行った。本講演ではその解析結果を報告する。&lt;/p&gt;

DOI： 10.11316/jpsgaiyo.72.1.0_64

記述言語：日本語   出版者・発行元：一般社団法人 日本物理学会  

<p>ある種の核における中性子共鳴吸収反応では時間反転対称性の破れの効果が増幅される可能性が示唆されている。その核の候補の一つである^139^Laの中性子共鳴吸収反応での増幅の効果を知るために共鳴パラメータを決定する必要がある。本講演では、J-PARCで行った実験のデータを解析した結果を報告する。</p>

DOI： 10.11316/jpsgaiyo.72.1.0_360

CiNii Research

記述言語：日本語  

記述言語：日本語  

記述言語：日本語