New material exploration to enhance neutron intensity below cold neutrons; Nanosized graphene flower aggregation

Teshigawara, Makoto; Ikeda, Yujiro*; Yan, M.*; Muramatsu, Kazuo*; Sutani, Koichi*; Fukuzumi, Masafumi*; Noda, Yohei*; Koizumi, Satoshi*; Saruta, Koichi; Otake, Yoshie*

Nanomaterials (Internet), 13(1), p.76_1 - 76_9, 2023/01

https://doi.org/10.3390/nano13010076

To enhance neutron intensity below cold neutrons, it is proposed that nanosized graphene aggregation could facilitate neutron coherent scattering under particle size conditions similar to nanodiamond. It might also be possible to use it in high neutron radiation conditions due to graphene's strong sp2 bonds. Using the RIKEN accelerator-driven compact neutron source and iMATERIA at J-PARC, we performed neutron measurement experiments, total neutron cross-section, and small-angle neutron scattering on nanosized graphene aggregation. The measured data revealed, for the first time, that nanosized graphene aggregation increased the total cross-sections and small-angle scattering in the cold neutron energy region, most likely due to coherent scattering, resulting in higher neutron intensities, similar to nanodiamond.

Dynamical response of transition-edge sensor microcalorimeters to a pulsed charged-particle beam

Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I.-H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.

IEEE Transactions on Applied Superconductivity, 31(5), p.2101704_1 - 2101704_4, 2021/08

https://doi.org/10.1109/TASC.2021.3067793

A superconducting transition-edge sensor (TES) microcalorimeter is an ideal X-ray detector for experiments at accelerator facilities because of good energy resolution and high efficiency. To study the performance of the TES detector with a high-intensity pulsed charged-particle beam, we measured X-ray spectra with a pulsed muon beam at the Japan Proton Accelerator Research Complex (J-PARC) in Japan. We found substantial temporal shifts of the X-ray energy correlated with the arrival time of the pulsed muon beam, which was reasonably explained by pulse pileup due to the incidence of energetic particles from the initial pulsed beam.

Deexcitation dynamics of muonic atoms revealed by high-precision spectroscopy of electronic X rays

Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I. H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.

Physical Review Letters, 127(5), p.053001_1 - 053001_7, 2021/07

https://doi.org/10.1103/PhysRevLett.127.053001

We observed electronic X rays emitted from muonic iron atoms using a superconducting transition-edge-type sensor microcalorimeter. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic and X rays together with the hypersatellite X rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the -shell electrons, accompanied by electron side-feeding. Assisted by a simulation, this data clearly reveals the electronic - and -shell hole production and their temporal evolution during the muon cascade process.

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, Tetsu*; Katayama, Ichiro*; Wada, Michiharu*; Iimura, Hideki; Sonnenschein, V.*; Iimura, Shun*; Takamine, Aiko*; Rosenbusch, M.*; Kojima, Takao*; Ahn, D. S.*; et al.

Progress of Theoretical and Experimental Physics (Internet), 2019(11), p.113D02_1 - 113D02_12, 2019/11

AA2019-0315.pdf:1.37MB

https://doi.org/10.1093/ptep/ptz120

An in-flight separator, BigRIPS, at RIBF in RIKEN provides each experiment with specific nuclides separated from many nuclides produced by projectile fragmentation or in-flight fission. In this process, nuclides other than separated ones are discarded on the slits in BigRIPS, although they include many nuclides interested from the view point of nuclear structure. In order to extract these nuclides for parasitic experiments, we are developing a method using laser ion-source (PALIS). A test experiment with Se beam from RIBF has been performed by using a gas cell set in BigRIPS. Unstable nuclides around Se were stopped in the gas cell in accordance with a calculation using LISE code. The stopping efficiency has been estimated to be about 30%. As a next step, we will establish the technique for extracting reaction products from the gas cell.

Radiation response of silicon carbide metal-oxide-semiconductor transistors in high dose region

Oshima, Takeshi; Yokoseki, Takashi; Murata, Koichi; Matsuda, Takuma; Mitomo, Satoshi; Abe, Hiroshi; Makino, Takahiro; Onoda, Shinobu; Hijikata, Yasuto*; Tanaka, Yuki*; et al.

Japanese Journal of Applied Physics, 55(1S), p.01AD01_1 - 01AD01_4, 2016/01

https://doi.org/10.7567/JJAP.55.01AD01

Effect of humidity and temperature on the radiation response of SiC MOSFETs

Takeyama, Akinori; Matsuda, Takuma; Yokoseki, Takashi; Mitomo, Satoshi; Murata, Koichi; Makino, Takahiro; Onoda, Shinobu; Tanaka, Yuki*; Kandori, Mikio*; Yoshie, Toru*; et al.

Proceedings of 11th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-11) (Internet), p.134 - 137, 2015/11

Synchrotron oscillation relevant to transverse laser cooling in S-LSR

Jimbo, Koichi*; Soda, Hikaru*; Nakao, Masao*; Yuri, Yosuke; Tongu, Hiromu*; Noda, Akira*

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1057 - 1059, 2014/06

http://www.pasj.jp/web_publish/pasj10/proceedings/PDF/SUP0/SUP068.pdf

Simulation study on transverse laser cooling and crystallization of heavy-ion beams at the cooler storage ring S-LSR

Yuri, Yosuke; Osaki, Kazuya*; Okamoto, Hiromi*; He, Z.*; Soda, Hikaru*; Noda, Akira*; Nakao, Masao*; Tongu, Hiromu*; Jimbo, Koichi*

Proceedings of Workshop on Beam Cooling and Related Topics (COOL '13) (Internet), p.162 - 165, 2013/11

http://accelconf.web.cern.ch/AccelConf/COOL2013/papers/tham1ha03.pdf

Parameter optimization for multi-dimensional laser cooling of an ion beam in the storage ring S-LSR

He, Z.*; Wei, J.*; Osaki, Kazuya*; Okamoto, Hiromi*; Noda, Akira*; Nakao, Masao*; Soda, Hikaru*; Yuri, Yosuke; Jimbo, Koichi*

Proceedings of 25th North American Particle Accelerator Conference (NA-PAC '13) (Internet), p.1298 - 1300, 2013/09

http://accelconf.web.cern.ch/AccelConf/PAC2013/papers/thpho01.pdf

Efficiency enhancement of indirect transverse laser cooling with synchro-betatron resonant coupling by suppression of beam intensity

Soda, Hikaru*; Nakao, Masao*; Tongu, Hiromu*; Jimbo, Koichi*; Osaki, Kazuya*; Okamoto, Hiromi*; Yuri, Yosuke; He, Z.*; Grieser, M.*; Noda, Akira*

Japanese Journal of Applied Physics, 52(3), p.030202_1 - 030202_4, 2013/03

https://doi.org/10.7567/JJAP.52.030202