Measurement of leakage beam from RF chopper

Kitamura, Ryo; Fuwa, Yasuhiro; Kuriyama, Yasutoshi*; Miyao, Tomoaki*

Proceedings of 21st Annual Meeting of Particle Accelerator Society of Japan (Internet), p.233 - 234, 2024/10

https://www.pasj.jp/web_publish/pasj2024/proceedings/PDF/WEP0/WEP008.pdf

Design improvement of bipolar correction magnet with permanent magnets

Kuriyama, Yasutoshi*; Iwashita, Yoshihisa*; Fuwa, Yasuhiro; Terunuma, Nobuhiro*

IEEE Transactions on Applied Superconductivity, 34(5), p.4004005_1 - 4004005_5, 2024/08

https://doi.org/10.1109/TASC.2024.3365099

We are developing a correction magnet for charged particle beams using permanent magnets. By rotating the rod of the permanent magnet that generates the magnetic field, the magnetic field can be changed to bipolarity. To verify the principle of this bi-polarity change, a prototype was built, and its performance was evaluated. The performance evaluation of the prototype machine revealed that the inhomogeneity of the remanent magnetization of the permanent magnet has a significant effect on the multipole component. To suppress this effect, a compensating magnet with additional anisotropic intermediate poles is being considered.

Development of new data acquisition system for several beam monitors in J-PARC RCS

Yoshimoto, Masahiro; Takahashi, Hiroki; Harada, Hiroyuki; Chimura, Motoki; Fuwa, Yasuhiro; Hayashi, Naoki; Kuriyama, Yasutoshi*; Sawabe, Yuki*; Hatakeyama, Shuichiro*

Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.839 - 843, 2023/11

https://www.pasj.jp/web_publish/pasj2023/proceedings/PDF/FRP0/FRP08.pdf

In the J -PARC 3GeV synchrotron accelerator (RCS), a new signal processing system for beam monitors is been developing to replace the existing system for the main beam monitors that monitor the stability of the accelerator: beam loss monitor, beam position monitor and beam current monitor. The new system will consist of a TAG server and an ADC module that can be used commonly for the three main monitors. The main design concepts of the new system are: (1) the TAG server divides various beam J-PARC tag information to each ADC module, (2) the ADC module converts acquisition data from beam monitors to digital signals by ADC and performs high-speed analysis by FPGA with switching analysis methods to suit each monitor, (3) the ADC module periodically outputs the analysis data with tag information by packing the signal processing data of all shots for about 10 seconds, and also outputs any one shot data on-demand, and (4) the raw waveform data, the latest four shots of FFT-related data in the process of analysis and bunch data for each cycle are stored in the internal memory of the ADC module, and the data can be read out as needed. In this presentation, we will report on the progress of the data acquisition test of tag information reading and beam monitor signals using the prototype under development.

Measurement of 107-MeV proton-induced double-differential thick target neutron yields for Fe, Pb, and Bi using a fixed-field alternating gradient accelerator at Kyoto University

Iwamoto, Hiroki; Nakano, Keita; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Sugihara, Kenta; Nishio, Katsuhisa; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; et al.

Journal of Nuclear Science and Technology, 60(4), p.435 - 449, 2023/04

https://doi.org/10.1080/00223131.2022.2115423

Double-differential thick target neutron yields (TTNYs) for Fe, Pb, and Bi targets induced by 107-MeV protons were measured using the fixed-field alternating gradient accelerator at Kyoto University for research and development of accelerator-driven systems (ADSs) and fundamental ADS reactor physics research at the Kyoto University Critical Assembly (KUCA). Note that TTNYs were obtained with the time-of-flight method using a neutron detector system comprising eight neutron detectors; each detector has a small NE213 liquid organic scintillator and photomultiplier tube. The TTNYs obtained were compared with calculation results using Monte Carlo-based spallation models (i.e., INCL4.6/GEM, Bertini/GEM, JQMD/GEM, and JQMD/SMM/GEM) and the evaluated high-energy nuclear data library, i.e., JENDL-4.0/HE, implemented in the particle and heavy iontransport code system (PHITS). All models, including JENDL-4.0/HE, failed to predict high-energy peaks at a detector angle of 5. Comparing the energy- and angle-integrated spallation neutron yields at energies of 20 MeV estimated using the measured TTNYs and the PHITS indicated that INCL4.6/GEM would be suitable for the Monte Carlo transport simulation of ADS reactor physics experiments at the KUCA.

Measurement of 107-MeV proton-induced double-differential neutron yields for iron for research and development of accelerator-driven systems

Iwamoto, Hiroki; Nakano, Keita; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; Yashima, Hiroshi*; Nishio, Katsuhisa; et al.

JAEA-Conf 2022-001, p.129 - 133, 2022/11

https://doi.org/10.11484/jaea-conf-2022-001

For accurate prediction of neutronic characteristics for accelerator-driven systems (ADS) and a source term of spallation neutrons for reactor physics experiments for the ADS at Kyoto University Critical Assembly (KUCA), we have launched an experimental program to measure nuclear data on ADS using the Fixed Field Alternating Gradient (FFAG) accelerator at Kyoto University. As part of this program, the proton-induced double-differential thick-target neutron-yields (TTNYs) and cross-sections (DDXs) for iron have been measured with the time-of-flight (TOF) method. For each measurement, the target was installed in a vacuum chamber on the beamline and bombarded with 107-MeV proton beams accelerated from the FFAG accelerator. Neutrons produced from the targets were detected with stacked, small-sized neutron detectors composed of the NE213 liquid organic scintillators and photomultiplier tubes, which were connected to a multi-channel digitizer mounted with a field-programmable gate array (FPGA), for several angles from the incident beam direction. The TOF spectra were obtained from the detected signals and the FFAG kicker magnet's logic signals, where gamma-ray events were eliminated by pulse shape discrimination applying the gate integration method to the FPGA. Finally, the TTNYs and DDXs were obtained from the TOF spectra by relativistic kinematics.

Improvement of inner surface inspection system for superconducting cavities applying image processing technique

Kuriyama, Yasutoshi*; Iwashita, Yoshihisa*; Hirota, Katsuya*; Hayano, Hitoshi*; Fuwa, Yasuhiro

Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.32 - 35, 2019/10

https://www.pasj.jp/web_publish/pasj2019/proceedings/PDF/WEOH/WEOH06.pdf

Research and development of gradient enhancement of superconducting RF accelerating cavity is carried out by accelerator research institute in the world, but defects on the cavity surface limit accelerating electric field. Therefore, development of "Inside inspection system for superconducting accelerated cavity" that optically visualizes the state of the inner surface of the superconducting cavity has been carried out, and results have been achieved. In this research, we apply image processing technology that has developed remarkably in recent years to the internal inspection system, and advanced the defect recognition method. Extraction of depth information and image synthesis were performed from images obtained with different focal positions with the camera for internal surface inspection. Also, by performing pattern recognition processing on the images, automatic detection of defects has become possible. By integrating these techniques into the cavity inner surface inspection system, it becomes possible to shorten the scan time for defect search and acquire the defect shape.

Radiation damage calculation in PHITS and benchmarking experiment for cryogenic-sample high-energy proton irradiation

Iwamoto, Yosuke; Matsuda, Hiroki; Meigo, Shinichiro; Satoh, Daiki; Nakamoto, Tatsushi*; Yoshida, Makoto*; Ishi, Yoshihiro*; Kuriyama, Yasutoshi*; Uesugi, Tomonori*; Yashima, Hiroshi*; et al.

Proceedings of 61st ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (HB 2018) (Internet), p.116 - 121, 2018/07

https://doi.org/10.18429/JACoW-HB2018-TUP2WE03

The radiation damage model in the radiation transport code PHITS has been developed to calculate the basic data of the radiation damage including the energy of the target Primary Knock on Atom (PKA). For the high-energy proton incident reactions, a target PKA created by the secondary particles was more dominant than a target PKA created by the projectile. To validate the radiation damage model in metals irradiated by 100 MeV protons, we developed a proton irradiation device with a Gifford-McMahon cryocooler to cryogenically cool wire samples. By using this device, the defect-induced electrical resistivity changes related to the DPA cross section of copper and aluminum were measured under irradiation with 125 and 200 MeV protons at cryogenic temperature. A comparison of the experimental data with the calculated results indicates that the DPA cross section with defect production efficiencies provide better quantitative descriptions.

Measurement and analysis of 107-MeV proton-induced neutron yields for iron, lead and bismuth

Iwamoto, Hiroki; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Sugihara, Kenta; Nakano, Keita; Nishio, Katsuhisa; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; et al.

no journal, , 

For the purpose of research and development of accelerator-driven nuclear transmutation systems, neutron yields of 107-MeV proton incident on iron, lead and bismuth targets were measured by the flight time method using the FFAG accelerator at Kyoto University. The energy spectra of the neutron yield obtained by the measurements were compared with results of particle transport analysis with the nuclear reaction models (INCL4.6/GEM, Bertini/GEM, JQMD/GEM and JQMD/SMM/GEM) incorporated in the Monte Carlo particle transport calculation code PHITS and the nuclear data library JENDL-4.0/HE. As a result, it was found that the INCL4.6/GEM, which was the reference model of PHITS, best reproduced the experimental values.

None

Fuwa, Yasuhiro; Nakano, Hideto; Kitamura, Ryo; Kuriyama, Yasutoshi*; Iwashita, Yoshihisa*; Okuno, Yasuki*; Hayano, Hitoshi*

no journal, , 

no abstracts in English

Measurement of the damage rate of copper irradiated with 125 MeV protons at 12 K and comparison with calculated result with the PHITS code

Iwamoto, Yosuke; Yoshiie, Toshimasa*; Yoshida, Makoto*; Nakamoto, Tatsushi*; Sakamoto, Masaaki*; Kuriyama, Yasutoshi*; Uesugi, Tomonori*; Ishi, Yoshihiro*; Xu, Q.*; Yashima, Hiroshi*; et al.

no journal, , 

To validate Monte Carlo code PHITS for the prediction of radiation damage in metals, the damage rate (defect-induced electrical resistivity changes / particle fluence) related to the displacement cross-section of copper were measured with 125 MeV proton irradiation under 12 K at the FFAG facility in the Kyoto University Research Reactor Institute. The sample was a copper wire with a 250-m diameter and 99.999% purity and was cooled by conduction cooling. After 125 MeV proton irradiation with 1.4510 protons/m at 12 K, the total resistivity increase was 4.9410m (resistance increase: 1.53), while the resistivity of copper before irradiation was 9.49 10m (resistance: 29.41). Comparison with other experimental results indicated that the damage rate by 125 MeV protons is almost same with those by 1.1 GeV protons and is higher than the damage rate by 14 MeV neutrons by a factor of 1.4. For the comparison with the PHITS results, the experimental data is smaller than the calculated result without the defect production efficiency by a factor of about 2.5 and that with the defect production efficiency by a factor of about 1.4, respectively. It indicates that the defect production efficiency in PHITS gives a good quantitative description of the displacement cross-section.