Sample Radioactivity Evaluation Program (SARE) at Materials and Life Science Facility in J-PARC

Harada, Masahide; Yamaguchi, Yuji; Hashimoto, Norimichi*; Ito, Taku*; Tajima, Takahiro*; Oku, Takayuki; Haga, Katsuhiro; Ikeda, Hiroshi*; Tamura, Satoshi*

JPS Conference Proceedings (Internet), 45, p.011184_1 - 011184_4, 2026/06

https://doi.org/10.7566/JPSCP.45.011184

At Materials and Life Science Facility in J-PARC, 3 GeV and 1 MW pulsed proton beam hits mercury and carbon targets and intense neutron and muon beams are provided for various measurements. As samples in the measurements are activated, estimation of radioactivity of samples is very necessary for a radiation safety of user experiments. Therefore, estimation system, SAmple Radioactivity Evaluation program (SARE), is developed. SARE can estimate radioactivity of samples at each neutron and muon beam line with neutron flux and activation cross section. The neutron flux data was applied from references and the activation cross section data was obtained from DCHAIN-SP-2001. The activation of negative-muon can be also estimated from a database. SARE has a user-friendly interface of Web servlet based on JAVA and JAVA script and can select various conditions for the estimation. In the presentation, we will introduce SARE and validation results performed at BL10 with the foil-activation method.

First constraint on the P-odd/T-odd cross section in polarized neutron transmission through transversely polarized La

Nakabe, Rintaro; Endo, Shunsuke; Kambara, Wataru*; Kawamura, Shihori; Kimura, Atsushi; Kobayashi, Ryuju; Oku, Takayuki; Okudaira, Takuya*; Sakai, Kenji; Shinohara, Takenao; et al.

Progress of Theoretical and Experimental Physics (Internet), 2026(6), p.063D01_1 - 063D01_15, 2026/06

https://doi.org/10.1093/ptep/ptag088

We report the first constraint on time-reversal invariance violating (TRIV) effects in polarized neutron transmission through a transversely polarized La target. We formulate the transmission asymmetry within the density matrix formalism, explicitly incorporating the forward scattering amplitude of La including tensor polarization terms up to third-rank. The formalism is applied to existing transmission data originally obtained to measure the spin-dependent cross section near the ~eV -wave resonance. Since these data were not optimized for P-odd/T-odd observables, the attainable sensitivity is intrinsically limited; nevertheless, they provide a useful test of the formalism on real experimental data. No statistically significant TRIV signal is observed. By analyzing the global structure in the parameter space, we obtain an upper limit of at the 90% confidence level. This corresponds to an upper limit on the resonance-averaged TRIV cross section of . These results validate the present theoretical framework and provide guidance for future dedicated TRIV searches in polarized neutron transmission experiments.

Development of the direct deuteration method for amino acids and characterization of deuterated tryptophan

Shibazaki, Chie; Oku, Takayuki; 5 of others*

Bioengineering (Internet), 12(9), p.981_1 - 981_19, 2025/09

https://doi.org/10.3390/bioengineering12090981

Proteins and peptides are vital biomolecules, and deuterated amino acids are increasingly applied in areas such as drug discovery, metabolic tracing, and neutron scattering studies. In this study, we performed deuteration on all 20 proteinogenic amino acids, including their side chains, and established efficient methods for 13 amino acids. Using a Pt/C-catalyzed hydrogen-deuterium exchange reaction, the reaction parameters were optimized to achieve the selective and stable incorporation of deuterium. In addition, the resulting deuterated compounds, focusing on tryptophan, were characterized in order to assess their physicochemical properties. Because the deuteration reaction caused significant racemization of amino acids, deuterated D/L-tryptophan was isolated using a chiral separation method. Deuterated tryptophan characterization studies confirmed that the photostability was markedly enhanced by deuteration, whereas the acid stability showed no clear isotopic effect. The X-ray crystal structure analyses revealed minimal changes upon the hydrogen-to-deuterium substitution. These results provide a robust platform for the supply of deuterated amino acids, facilitating their application in drug development, structural analysis, and creation of advanced functional biomaterials.

Development of a compact He neutron spin filter at J-PARC

Takahashi, Shingo; Kiyanagi, Ryoji; Okudaira, Takuya*; Takada, Shusuke*; Kobayashi, Ryuju; Okuizumi, Mao; Ino, Takashi*; Asai, Kanta*; Tsuchikawa, Yusuke; Oikawa, Kenichi; et al.

Nuclear Instruments and Methods in Physics Research A, 1075, p.170410_1 - 170410_8, 2025/06

https://doi.org/10.1016/j.nima.2025.170410

Transverse asymmetry of individual rays in the La()La reaction

Okuizumi, Mao*; Auton, C. J.*; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ino, Takashi*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; et al.

Physical Review C, 111(3), p.034611_1 - 034611_6, 2025/03

https://doi.org/10.1103/PhysRevC.111.034611

Circular polarization measurement for individual gamma rays in capture reactions with intense pulsed neutrons

Endo, Shunsuke; Abe, Ryota*; Fujioka, Hiroyuki*; Ino, Takashi*; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kawamura, Shiori*; Kimura, Atsushi; Kitaguchi, Masaaki*; Kobayashi, Ryuju*; et al.

European Physical Journal A, 60(8), p.166_1 - 166_10, 2024/08

https://doi.org/10.1140/epja/s10050-024-01392-6

Nanometer-thick crystalline ice plates in rapidly-frozen glucose solution observed by spin-contrast-variation small-angle neutron scattering

Kumada, Takayuki; Nakagawa, Hiroshi; Miura, Daisuke; Sekine, Yurina; Motokawa, Ryuhei; Hiroi, Kosuke; Inamura, Yasuhiro; Oku, Takayuki; Oishi, Kazuki*; Morikawa, Toshiaki*; et al.

Hamon, 34(2), p.50 - 53, 2024/05

https://doi.org/10.5611/hamon.34.2_50

Spin-contrast-variation (SCV) small-angle neutron scattering (SANS) enabled us to determine structure of nano-ice crystals that were generated in rapidly frozen sugar solution. In the frozen glucose solution, we found that the nano-ice crystals formed a planar structure with a radius larger than several tens of nanometers and a thickness of 2-3 nm, which was close to the critical nucleation size of ice crystals in supercooled water. This result suggests that the glucose molecules were preferentially bound to a specific face of nano-ice crystals, and then blocked the crystal growth perpendicular to that face.

Interpenetration of rubber and silane coupling agent on an inorganic substrate revealed by spin-contrast-variation neutron reflectivity

Kumada, Takayuki; Iwahara, Daisuke*; Nishitsuji, Shotaro*; Akutsu, Kazuhiro*; Miura, Daisuke; Motokawa, Ryuhei; Sugita, Tsuyoshi; Torikai, Naoya*; Amino, Naoya*; Oku, Takayuki; et al.

Journal of Physical Chemistry C, 128(21), p.8797 - 8802, 2024/05

https://doi.org/10.1021/acs.jpcc.4c00963

We elucidated the entanglement of polybutadiene and silane coupling agent (SCA) molecules bound to Si substrates using spin-contrast-variation (SCV) neutron reflectivity (NR). In an annealed integral blend film of polybutadiene and SCA, a SCA layer generated on the Si substrate was composed of 70 vol. percent SCA molecules extended perpendicularly from the silicon substrate and entangled with 30 vol. percent polybutadiene molecules. By contrast, in an SCA-precoated polybutadiene film, the SCA-precoated layer is composed of densely packed SCA molecules forming crystal-like structure, and thus did not become entangled with the postcoated polybutadiene molecules. This poor entanglement resulted in poor binding between polybutadiene and Si substrate.

High sensitivity of a future search for effects of -odd/-odd interactions on the 0.75 eV -wave resonance in + forward transmission determined using a pulsed neutron beam

Nakabe, Rintaro*; Auton, C. J.*; Endo, Shunsuke; Fujioka, Hiroyuki*; Gudkov, V.*; Hirota, Katsuya*; Ide, Ikuo*; Ino, Takashi*; Ishikado, Motoyuki*; Kambara, Wataru*; et al.

Physical Review C, 109(4), p.L041602_1 - L041602_4, 2024/04

https://doi.org/10.1103/PhysRevC.109.L041602

Neutron transmission CB-KID imager using samples placed at room temperature

Ishida, Takekazu*; Vu, TheDang*; Shishido, Hiroaki*; Aizawa, Kazuya; Oku, Takayuki; Oikawa, Kenichi; Harada, Masahide; Kojima, Kenji M*; Miyajima, Shigeyuki*; Koyama, Tomio*; et al.

Journal of Low Temperature Physics, 214(3-4), p.152 - 157, 2024/02

https://doi.org/10.1007/s10909-023-03030-9