Integrated thermal power measurement in the modified STACY for the performance inspections

Araki, Shohei; Aizawa, Eiju; Murakami, Takahiko; Arakaki, Yu; Tada, Yuta; Kamikawa, Yutaka; Hasegawa, Kenta; Yoshikawa, Tomoki; Sumiya, Masato; Seki, Masakazu; et al.

Annals of Nuclear Energy, 217, p.111323_1 - 111323_8, 2025/07

https://doi.org/10.1016/j.anucene.2025.111323

JAEA has modified the STACY from a homogeneous system using solution fuel to a heterogeneous system using fuel rods in order to obtain criticality characteristics of fuel debris. The modification of the STACY was completed in December 2023. A series of performance inspections were conducted for the start of experimental operations. A new thermal power calibration is required for the performance inspections in order to operate at less than 200 W, which is the permitted thermal power. However, the thermal power measurement method and calibration data used in the former STACY is no longer available due to the modification of the modified STACY. We measured the thermal power of the STACY using the activation method that was improved to adapt to the measurement condition and calibrated the power meter system. Since the positions where activation foils could be installed were very limited, the thermal power was evaluated using numerical calculations supplemented by experimental data. Neutron flux data at the positions of the activation foil was measured by the activation method. Neutron distribution in the core was calculated by the Monte Carlo code MVP. A response function of the activation foil was calculated using the PHITS. The uncertainty of the thermal power measurement was conservatively estimated to be about 15%. Four operations were conducted for the thermal power measurement. The power meter was calibrated by using three operational data and tested with the one operational data. It was found that the indicated value of the meter adjusted by the STACY before the modification work would tend to overestimate the actual output by about 40%. In addition, the current calibration was able to calibrate the meter to within 3% accuracy.

Evaluation of the performance of event reconstruction algorithms in the JSNS experiment using a Cf calibration source

Lee, D. H.*; Dodo, Taku; Haga, Katsuhiro; Harada, Masahide; Hasegawa, Shoichi; Kasugai, Yoshimi; Kinoshita, Hidetaka; Masuda, Shiho; Meigo, Shinichiro; Sakai, Kenji; et al.

Nuclear Instruments and Methods in Physics Research A, 1072, p.170216_1 - 170216_6, 2025/03

https://doi.org/10.1016/j.nima.2025.170216

First measurement of missing energy due to nuclear effects in monoenergetic neutrino charged-current interactions

Marzec, E.*; Dodo, Taku; Haga, Katsuhiro; Harada, Masahide; Hasegawa, Shoichi; Kasugai, Yoshimi; Kinoshita, Hidetaka; Masuda, Shiho; Meigo, Shinichiro; Sakai, Kenji; et al.

Physical Review Letters, 134, p.081801_1 - 081801_9, 2025/00

https://doi.org/10.1103/PhysRevLett.134.081801

Study on the accidental background of the JSNS experiment

Lee, D. H.*; Dodo, Taku; Haga, Katsuhiro; Harada, Masahide; Hasegawa, Shoichi; Kasugai, Yoshimi; Kinoshita, Hidetaka; Masuda, Shiho; Meigo, Shinichiro; Sakai, Kenji; et al.

European Physical Journal C, 84, p.409_1 - 409_6, 2024/04

https://doi.org/10.1140/epjc/s10052-024-12778-7

Optimization in granulation conditions for adsorbent of extraction chromatography

Hasegawa, Kenta; Goto, Ichiro*; Miyazaki, Yasunori; Ambai, Hiromu; Watanabe, So; Watanabe, Masayuki; Sano, Yuichi; Takeuchi, Masayuki

Mechanical Engineering Journal (Internet), 11(2), p.23-00407_1 - 23-00407_8, 2024/04

https://doi.org/10.1299/mej.23-00407

The Acrylic vessel for JSNS-II neutrino target

Shin, C. D.*; Dodo, Taku; Haga, Katsuhiro; Harada, Masahide; Hasegawa, Shoichi; Kasugai, Yoshimi; Kinoshita, Hidetaka; Masuda, Shiho; Meigo, Shinichiro; Sakai, Kenji; et al.

Journal of Instrumentation (Internet), 18(12), p.T12001_1 - T12001_9, 2023/12

https://doi.org/10.1088/1748-0221/18/12/T12001

Competitive distribution of europium and samarium based on reaction rate-limiting process in nitrilotriacetamide extractant-impregnated polymer-coated silica particles

Miyagawa, Akihisa*; Hayashi, Naoki*; Iwamoto, Hibiki*; Arai, Tsuyoshi*; Nagatomo, Shigenori*; Miyazaki, Yasunori; Hasegawa, Kenta; Sano, Yuichi; Nakatani, Kiyoharu*

Bulletin of the Chemical Society of Japan, 96(9), p.1019 - 1025, 2023/09

https://doi.org/10.1246/bcsj.20230142

In the present study, we have elucidated the mass transfer mechanism of Eu(III) and Sm(III) in the solution with these ions in single nitrilotriacetamide (NTA) extractant-impregnated polymer-coated silica particle. The rate-limiting process of mass transfer was the reaction process of ions with NTA molecules, in which the NO ions were not involved, which was consistent with that obtained in single ion distribution system.

Evaluation of the remaining spent extraction solvent in vermiculite after leaching tests via PIXE analysis

Arai, Yoichi; Watanabe, So; Hasegawa, Kenta; Okamura, Nobuo; Watanabe, Masayuki; Takeda, Keisuke*; Fukumoto, Hiroki*; Ago, Tomohiro*; Hagura, Naoto*; Tsukahara, Takehiko*

Nuclear Instruments and Methods in Physics Research B, 542, p.206 - 213, 2023/09

https://doi.org/10.1016/j.nimb.2023.07.003

Development of engineering scale extraction chromatography separation system, 2; Spray drying granulation of silica support for adsorbent

Hasegawa, Kenta; Goto, Ichiro*; Miyazaki, Yasunori; Ambai, Hiromu; Watanabe, So; Watanabe, Masayuki; Sano, Yuichi; Takeuchi, Masayuki

Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 5 Pages, 2023/05

The Muon linac project at J-PARC

Kondo, Yasuhiro; Kitamura, Ryo; Fuwa, Yasuhiro; Morishita, Takatoshi; Moriya, Katsuhiro; Takayanagi, Tomohiro; Otani, Masashi*; Cicek, E.*; Ego, Hiroyasu*; Fukao, Yoshinori*; et al.

Proceedings of 31st International Linear Accelerator Conference (LINAC 2022) (Internet), p.636 - 641, 2022/09

https://doi.org/10.18429/JACoW-LINAC2022-WE1AA05

The muon linac project for the precise measurement of the muon anomalous magnetic and electric dipole moments, which is currently one of the hottest issues of the elementary particle physics, is in progress at J-PARC. The muons from the J-PARC muon facility are once cooled to room temperature, then accelerated up to 212 MeV with a normalized emittance of 1.5 mm mrad and a momentum spread of 0.1%. Four types of accelerating structures are adopted to obtain the efficient acceleration with a wide beta range from 0.01 to 0.94. The project is moving into the construction phase. We already demonstrated the re-acceleration scheme of the decelerated muons using a 324-MHz RFQ in 2017. The high-power test of the 324-MHz Interdigital H-mode (IH) DTL using a prototype cavity was performed in 2021. The fabrication of the first module of 14 modules of the 1296-MHz Disk and Washer (DAW) CCL will be done to confirm the production process. Moreover, the final design of the travelling wave accelerating structure for the high beta region is also proceeding. In this paper, the recent progress toward the realization of the world first muon linac will be presented.