Pulse bending magnet and septum magnet for 3-GeV proton beam transport line

Yamaguchi, Yuji; Kondo, Yasuhiro; Meigo, Shinichiro; Takayanagi, Tomohiro; Fujimori, Hiroshi*; Shinozaki, Shinichi

Proceedings of 22nd Annual Meeting of Particle Accelerator Society of Japan (Internet), p.655 - 660, 2026/03

https://www.pasj.jp/web_publish/pasj2025/proceedings/PDF/THP0/THP061.pdf

Preliminary designs of new bending magnets have been considered for the second target station (TS2) of Materials and Life Science Experimental Facility (MLF), J-PARC. To give a design approach for the bending magnets, several examples of bending magnets, such as a pulse bending magnet and a septum magnet were reviewed. The reviewed magnet specifications compared with requirements for the new bending magnets indicate that the new pulse bending magnet requires a new design idea, while the new septum magnet can be designed based on the previous design of an extraction septum magnet for the 3-GeV synchrotron in J-PARC. The new design idea for the pulse bending magnet and the septum magnet design idea based on the previous one are presented.

Simulations of magnetic field effects on 3-GeV proton beam brought by magnets for muon beam in future proton beam transport line of J-PARC

Yamaguchi, Yuji; Kondo, Yasuhiro; Meigo, Shinichiro; Shinozaki, Shinichi; Takayanagi, Tomohiro; Fujimori, Hiroshi*; Kawamura, Naritoshi*

Journal of Physics; Conference Series, 3094(1), p.012023_1 - 012023_5, 2025/09

https://doi.org/10.1088/1742-6596/3094/1/012023

The 3-GeV proton beam from the rapid cycling synchrotron (RCS) of J-PARC is transported to the spallation neutron source at Materials and Life Science Experimental Facility (MLF) by a 3-GeV RCS to Neutron facility Beam Transport (3NBT) line. Recently, the first design idea of a new proton beam transport line has been proposed for a future target station of the MLF (TS2). In the present study, proton beam transport is simulated near the TS2 target where a bending magnet and a solenoid are located for muon beam transport. The purposes are to clarify the magnetic field effects on the proton beam by the magnets and to present a method to correct each effect. Orbit deviation by the bending magnet and vertical size expansion due to profile rotation by the solenoid can be corrected by installing additional bending magnets and a solenoid with reversal magnetic field, respectively. The correction method is expected to be effective and also needs to be studied further for detail design.

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(8), p.081801_1 - 081801_9, 2025/02

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

-induced total reaction cross sections based on the intranuclear cascade model

Nakano, Masahiro*; Yamaguchi, Yuji; Furuta, Toshimasa*; Uozumi, Yusuke*

Physical Review C, 110(6), p.064620_1 - 064620_5, 2024/12

https://doi.org/10.1103/PhysRevC.110.064620

Alpha-induced total reaction cross sections in the low-energy region below 400 MeV are investigated using an intranuclear cascade model based on the extended framework for nucleon- and deuteron-induced reactions. Experimental data for C, Si, Ca, and Pb targets are reproduced well by calculations performed with reasonable parameters close to those determined in other studies. It is shown that two effects, namely, discrete level constraint (DLC) and the Coulomb effect, provide important contributions that depend on the incident- energy and target. The DLC effect is limited to a narrow region of low-energy and is very important in light targets. The Coulomb effect is decisive on cross sections in Pb, while the DLC contribution for the heavy target is small. It is concluded that this trend in the contribution of both effects is consistent with proton- and deuteron-induced total reaction cross sections.

SiC sensor wire test by heavy ion beam irradiation, 2

Meigo, Shinichiro; Yamaguchi, Yuji

Proceedings of 21st Annual Meeting of Particle Accelerator Society of Japan (Internet), p.853 - 858, 2024/10

https://www.pasj.jp/web_publish/pasj2024/proceedings/PDF/FRP0/FRP006.pdf

no abstracts in English

Investigation of solenoid fringe field based on change in 3-Gev proton beam orbit and the orbit correction

Yamaguchi, Yuji; Meigo, Shinichiro; Yamazaki, Takayuki*

Proceedings of 21st Annual Meeting of Particle Accelerator Society of Japan (Internet), p.239 - 243, 2024/10

https://www.pasj.jp/web_publish/pasj2024/proceedings/PDF/WEP0/WEP010.pdf

Fringe field of a secondary-particle capture solenoid magnet with three coils has been experimentally investigated placed at muon science facility in materials and life science experimental facility (MLF), J-PARC. To clarify relationship between the fringe field and excitation current of each coil and interference of fields by the coils, proton beam position changes in vertical direction were measured for 125(= 5) combinations of excitation currents using a multi-wire profile monitor located in front of the final target of MLF. The measured position changes show that the field by the most upstream coil is non-linear with its current while the fields by other coils are linear and that the field can be enhanced by excitation of multiple coils. The non-linearity of the filed by the most upstream coil has been introduced to the proton beam orbit correction, which has been demonstrated.

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

Double-differential cross sections for charged particle emissions from particle impinging on Al at 230 MeV/u

Furuta, Toshimasa*; Uozumi, Yusuke*; Yamaguchi, Yuji; Iwamoto, Yosuke; Koba, Yusuke*; Velicheva, E.*; Kalinnikov, V.*; Tsamalaidze, Z.*; Evtoukhovitch, P.*

Journal of Nuclear Science and Technology, 61(2), p.230 - 236, 2024/02

https://doi.org/10.1080/00223131.2023.2294192

Charged particle production from particle fragmentation reactions was investigated experimentally by measurement of 230-MeV/u particles bombarding an aluminum target. Double differential cross sections were measured for each ejectile of p, d, t, He, and He at laboratory angles between 15 and 60 deg. The results of analyzed data found the following common characteristics: (1) spectra of proton- and neutron-emission are similar in high energy region at forward angle, (2) triton-to-He ratio of -breakup yield is 1:2, which is similar to lower incident energy experiment, and (3) the shape of broad peak formed by He and particles could be explained by the process with collision between induced particle and target nucleus.

Development of secondary GeV protons utilization using scattering at beam window

Meigo, Shinichiro; Yamaguchi, Yuji; Nakano, Keita*; Sugihara, Kenta*

Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.132 - 136, 2023/01

https://www.pasj.jp/web_publish/pasj2022/proceedings/PDF/THOB/THOB01.pdf

J-PARC accelerator facility is the only accelerator facility in Japan that can provide proton beams in the energy range of 400 MeV or higher. In the J-PARC accelerator facility, it is difficult to install users' experimental equipment inside the proton beam duct in order to maintain stable user operation. In addition, due to the characteristics of the synchrotron accelerator, it is not possible to supply a low-intensity beam enough to confirm the detector. In addition, it is important to improve the intranuclear cascade model (INCL) for high-intensity proton accelerator facilities such as accelerator-driven transmutation systems (ADS), etc. In order to improve the INCL, DDX of the forward-most emitted particles is important, but new data should be obtained since there are few experimental data available. In order to promote space utilization and to improve the accuracy of the INCL, energy spectra of scattered protons at the Al beam window placed at the inlet of the 3NBT dump were measured. In the experiment, plastic scintillators were used with 400 MeV proton beam. The results show that the spectra have sharp peaks due to elastic scattering. The calculation of the PHITS code using INCL reproduced the sharp peak due to elastic scattering well, although it overestimated the contribution of quasi-elastic scattering in the experimental data. In conclusion, it is clear that the present method can be used to utilize protons in several GeV regions for space exploration.

Deuteron-induced nonelastic cross sections based on the intranuclear cascade model with independent incident particles under interaction potentials

Nakano, Masahiro*; Yamaguchi, Yuji; Uozumi, Yusuke*

Physical Review C, 106(1), p.014612_1 - 014612_8, 2022/07

https://doi.org/10.1103/PhysRevC.106.014612

Deuteron-induced nonelastic cross sections are studied in an extended intranuclear cascade (INC) model. A three-body framework of proton, neutron, and target is introduced into the INC model to incorporate naturally the decomposition and capture reactions from weakly bound deuterons. This framework includes three types of interaction potential, namely proton-target, neutron-target, and proton-neutron, the last of which causes the two nucleons in the deuteron to oscillate and play an important role in its breakup. The calculated results reproduce well the experimental data for C, Ca, Ni, and Pb targets with almost the same parameters as those determined previously for nucleon-induced nonelastic reactions.