Simulation study of heavy ion acceleration in J-PARC

Harada, Hiroyuki; Saha, P. K.; Kinsho, Michikazu

JPS Conference Proceedings (Internet), 33, p.011028_1 - 011028_6, 2021/03

https://doi.org/10.7566/JPSCP.33.011028

Recently, humankind had big discovery about neutron star, which is great big nuclear in the space. They are discovery of neutron star with twice mass of solar in 2010 and detection of gravity wave when two neutron stars incorporate in 2017. In order to understand the high dense matter like the neutron star, project of experimental researches by using accelerated heavy ion beams are planed in the world. The J-PARC facility consists of three accelerators, which are 400 MeV linac, 3 GeV rapid cycling synchrotron and Main Ring synchrotron. The accelerated MW class high intensity proton beams are used in many experiments. We have simulation study of the heavy ion beam in J-PARC to fully utilize high intensity ability of J-PARC. We propose the accelerator scheme of the beam in J-PARC and the intensity will reach to the world record. In my talk, I will introduce the accelerator scheme for the high-intensity heavy ion beam in J-PARC.

New method for high resolution analysis of betatron tune in a rapid cycling synchrotron or a booster ring

Harada, Hiroyuki; Hayashi, Naoki

JPS Conference Proceedings (Internet), 33, p.011027_1 - 011027_6, 2021/03

https://doi.org/10.7566/JPSCP.33.011027

The transverse betatron tune is one of the most important key parameters in a ring accelerator because emittance growth and beam loss occur directly in case of crossing a betatron resonance. Especially, the tune must be required a controll with high accuracy in high intensity proton accelerator from the view point of space charge force and the beam instability. In general measurement method, the betatron tune is measured by analyzing the detected beam oscillation on Fourier transform. However, the beam is quickly accelerated and the revolution frequency of the beam changes quickly in a rapid cycling synchrotron. So, the tune accuracy is not improved. A new method was developed for high resolution analysis of the tune and was evaluated in J-PARC accelerator. Tune accuracy was successfully improved from 0.013 to less than 0.001. Tune controll with high accuracy is base for high-intensity beam. In this paper, the new method is introduced and the measured result in J-PARC is report.

Flexible chopper gate pulse generation for the J-PARC RCS

Tamura, Fumihiko; Yamamoto, Masanobu; Yoshii, Masahito*; Sugiyama, Yasuyuki*; Hotchi, Hideaki; Saha, P. K.; Yoshimoto, Masahiro; Harada, Hiroyuki

JPS Conference Proceedings (Internet), 33, p.011021_1 - 011021_6, 2021/03

https://doi.org//10.7566/JPSCP.33.011021

Chopped beam injection is employed in the J-PARC RCS to avoid the longitudinal beam losses. A fast beam chopper is installed in the MEBT section of the linac. The chopper is driven by the gate pulses sent from the LLRF control system of the RCS. The delay from the zero crossing of the RCS rf and the width are set so that the beam pulse is injected into the proper phase position of the rf bucket. A unique feature of the J-PARC chopper gate pulse generation is thinning of the pulses. The thinning is useful to control the beam intensity without changing much the condition of the longitudinal painting. Also, the beam macro pulse can be trimmed down to a single intermediate pulse by setting the parameters. In this poster, we present the overview of the generation of the chopper gate pulse in the LLRF control system and various beam commissioning results utilizing the flexibility of it. Also, we discuss the upgrade of the chopper gate pulse generation.

High-spin states in S

Go, Shintaro*; Ideguchi, Eiji*; Yokoyama, Rin*; Aoi, Nori*; Azaiez, F.*; Furutaka, Kazuyoshi; Hatsukawa, Yuichi; Kimura, Atsushi; Kisamori, Keiichi*; Kobayashi, Motoki*; et al.

Physical Review C, 103(3), p.034327_1 - 034327_8, 2021/03

https://doi.org/10.1103/PhysRevC.103.034327

Decommissioning of the Uranium Enrichment Laboratory

Kokusen, Junya; Akasaka, Shingo*; Shimizu, Osamu; Kanazawa, Hiroyuki; Honda, Junichi; Harada, Katsuya; Okamoto, Hisato

JAEA-Technology 2020-011, 70 Pages, 2020/10

JAEA-Technology-2020-011.pdf:3.37MB

The Uranium Enrichment Laboratory in the Japan Atomic Energy Agency (JAEA) was constructed in 1972 for the purpose of uranium enrichment research. The smoke emitting accident on 1989 and the fire accident on 1997 had been happened in this facility. The research on uranium enrichment was completed in JFY1998. The decommissioning work was started including the transfer of the nuclear fuel material to the other facility in JFY2012. The decommissioning work was completed in JFY2019 which are consisting of removing the hood, dismantlement of wall and ceiling with contamination caused by fire accident. The releasing the controlled area was performed after the confirmation of any contamination is not remained in the target area. The radioactive waste was generated while decommissioning, burnable and non-flammable are 1.7t and 69.5t respectively. The Laboratory will be used as a general facility for cold experiments.

First measurement and online monitoring of the stripper foil thinning and pinhole formation to achieve a longer foil lifetime in high-intensity accelerators

Saha, P. K.; Yoshimoto, Masahiro; Hatakeyama, Shuichiro; Hotchi, Hideaki; Harada, Hiroyuki; Tamura, Fumihiko; Yamamoto, Kazami; Yamazaki, Yoshio; Kinsho, Michikazu; Irie, Yoshiro*

Physical Review Accelerators and Beams (Internet), 23(8), p.082801_1 - 082801_13, 2020/08

https://doi.org/10.1103/PhysRevAccelBeams.23.082801

J-PARC RCS; High-order field components inherent in the injection bump magnets and their effects on the circulating beam during multi-turn injection

Hotchi, Hideaki; Harada, Hiroyuki; Takayanagi, Tomohiro

Journal of Physics; Conference Series, 1350, p.012102_1 - 012102_5, 2019/11

https://doi.org/10.1088/1742-6596/1350/1/012102

1st Workshop against proposal by Young Researchers Association of the Japan Beam Physics Club "Discussing and Brainstorming for the World of Beam Physics in the thirty years ahead"

Sakaue, Kazuyuki*; Harada, Hiroyuki

Kasokuki, 16(3), p.204 - 206, 2019/10

Beam is used for research base of wide disciplines and contributes to science technology, and is supported by beam physics. Young Researchers Association of the Japan Beam Physics Club was established to lead to contribution for science technology by communication among young researchers at April 2018. Our club was newly established the workshop against proposal and the 1st workshop of "Discussing and Brainstorming for the World of Beam Physics in the thirty years ahead" was holed at Kyoto on July 30th 2019. This paper will report the 1st workshop.

Recent progress of the J-PARC RCS beam commissioning and operation; Efforts to realize a higher beam power beyond 1 MW

Hotchi, Hideaki; Harada, Hiroyuki; Hayashi, Naoki; Kinsho, Michikazu; Okabe, Kota; Saha, P. K.; Shobuda, Yoshihiro; Tamura, Fumihiko; Yamamoto, Kazami; Yamamoto, Masanobu; et al.

Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.574 - 578, 2019/07

https://www.pasj.jp/web_publish/pasj2019/proceedings/index.html

no abstracts in English

Study of heavy ion acceleration in J-PARC

Harada, Hiroyuki; Saha, P. K.; Kinsho, Michikazu

Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.179 - 182, 2019/07

https://www.pasj.jp/web_publish/pasj2019/proceedings/index.html

Recently, humankind had big discovery about neutron star, which is great big nuclear in the space. They are discovery of neutron star with twice mass of solar in 2010 and observation of gravity wave when two neutron start incorporate in 2017. In order to understand the high dense matter like the neutron star, project of experimental researches by using accelerated heavy ion beams become heated in the world, such RHIC-BES-II program, FAIR project, NICA project, etc. The J-PARC provides MW class high intensity proton beams to many experiments and researches. We have study of the heavy ion beam in J-PARC to fully utilize high intensity ability of J-PARC. We propose the accelerator scheme of the beam in J-PARC and the intensity will reach to the world record. In our talk, we will report the current status of proton beam and the accelerator scheme for the high-intensity heavy ion beam in J-PARC.