High density plasma calculation of J-PARC RF negative ion source

Shibata, Takanori*; Asano, Hiroyuki; Ikegami, Kiyoshi*; Naito, Fujio*; Nammo, Kesao*; Oguri, Hidetomo; Okoshi, Kiyonori; Shinto, Katsuhiro; Takagi, Akira*; Ueno, Akira

AIP Conference Proceedings 1869, p.030017_1 - 030017_11, 2017/08

https://doi.org/10.1063/1.4995737

From September 2014, operation of Cs-seeded, multi-cusp, Radio Frequency (RF), hydrogen negative ion source (J-PARC source) has been started. The operation for 1,000 hours of J-PARC source has been achieved with H beam current 45 mA and duty factor of 1.25 % (0.5 msec and 25 Hz). In the present study, mechanisms of hydrogen plasma ramp-up and H production/transport processes in the steady state (which lasts for few 100 us) are investigated by numerical modeling for RF plasma. In the simulation, charged particle (e, H, H, and Cs) transport, time variations of inductive and capacitive electromagnetic field, collision processes between charged and neutral (H, H) particles are solved simultaneously. The model is applied to KEK parallel computation System-A with 32 nodes and 256 GB memory in order to solve high density RF plasma up to around 10 m with adequate statisticity. In the presentation, time variations of plasma density distributions and average energy are shown with electromagnetic field variations.

Numerical study of plasma generation process and internal antenna heat loadings in J-PARC RF negative ion source

Shibata, Takanori*; Nishida, Kenjiro*; Mochizuki, Shintaro*; Mattei, S.*; Lettry, J.*; Hatayama, Akiyoshi*; Ueno, Akira; Oguri, Hidetomo; Okoshi, Kiyonori; Ikegami, Kiyoshi*; et al.

Review of Scientific Instruments, 87(2), p.02B128_1 - 02B128_3, 2016/02

BB2015-1473.pdf:4.28MB

https://doi.org/10.1063/1.4931787

A numerical model of plasma transport and electromagnetic field in the J-PARC RF ion source has been developed to understand relation between antenna coil heat loadings and plasma production/transport processes. From the calculation, the local plasma density increase is observed in the region close to the antenna coil. The magnetic field line with absolute magnetic flux density 30-120 Gauss results in the magnetization of electron which leads to high local ionization rate. The results suggest that modification of magnetic configuration can be made to reduce plasma heat flux onto the antenna.

Operating experience of the J-PARC linac

Hasegawa, Kazuo; Asano, Hiroyuki; Chishiro, Etsuji; Hori, Toshihiko; Ito, Takashi; Kobayashi, Tetsuya; Kondo, Yasuhiro; Namekawa, Yuya; Oguri, Hidetomo; Okoshi, Kiyonori; et al.

Proceedings of 24th International Linear Accelerator Conference (LINAC 2008) (CD-ROM), p.55 - 57, 2009/00

http://accelconf.web.cern.ch/accelconf/LINAC08/papers/mop004.pdf

The beam commissioning of the J-PARC linac started in November 2006 and 181 MeV acceleration was successfully achieved in January 2007. The linac has delivered beams to the 3 GeV Rapid Cycling Synchrotron for its commissioning, and then, the subsequent Main Ring Synchrotron and the neutron target commissioning. The linac uses a Cs-free LaB-driven ion source and 20 units of 324 MHz klystrons. As of June 2008, the operation times are about 3,000 and 6,000 hours for the ion source and the RF source, respectively. The operating experience of the linac is described.

Status of the ACS cavity development for the J-PARC linac energy upgrade

Ao, Hiroyuki; Hirano, Koichiro; Morishita, Takatoshi; Asano, Hiroyuki; Naito, Fujio*; Ueno, Akira; Ikegami, Masanori*; Hasegawa, Kazuo; Yamazaki, Yoshishige; Paramonov, V.*

Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.494 - 496, 2008/00

The J-PARC ACS cavity consists of many cell parts. For the mass production, the ACS requires about 1300 cell parts, so that it is important to reduce the machining time. In the previous ACS model, it took about three hours per one coupling slot. We, therefore, optimized the slot design, the tolerance, and the machining process. As a result, the machining time reduced to forty-five minutes per one slot. The four test cells were fabricated to measure the frequencies and Q-values, and these results were compared with the electromagnetic analysis with the Microwave Studio. Between the analysis and the measurement, the differences are 11.5 MHz and 45 MHz, respectively, for the accelerating mode, and for the coupling mode.

The DTL/SDTL alignment of the J-PARC linac

Morishita, Takatoshi; Asano, Hiroyuki; Ito, Takashi; Ueno, Akira; Hasegawa, Kazuo; Naito, Fujio*; Takasaki, Eiichi*; Tanaka, Hirokazu*; Yoshino, Kazuo*; Ikegami, Masanori*

Proceedings of 2007 Particle Accelerator Conference (PAC '07) (Internet), p.1523 - 1525, 2007/06

J-PARC linear accelerator components have been installed. The required alignment accuracy in the J-PARC linac is 0.1mm in transverse direction. In the DTL/SDTL section, the fine alignment was carried out by using an optical alignment telescope along with the cavity installation. The displacement of the DTL by the unit tank connection was monitored by a laser tracker to obtain the tolerable displacement between unit tanks. The heights of cavities and magnets were compensated form the unequal ground movement of the linac tunnel. Finally, all the cavities and magnets are aligned within the tolerable alignment error.

An Alignment of J-PARC linac

Morishita, Takatoshi; Ao, Hiroyuki; Ito, Takashi; Ueno, Akira; Hasegawa, Kazuo; Ikegami, Masanori*; Kubota, Chikashi*; Naito, Fujio*; Takasaki, Eiichi*; Tanaka, Hirokazu*; et al.

Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.2851 - 2853, 2005/00

In J-PARC linac, a precise alignment of accelerator components is essential for high quality beam acceleration. Markings have been placed on the floor, which act as a reference for the initial alignment at the installation. For a straight line alignment, the wire position sensor is placed on the offset position with respect to the beam center by a target holder. The hydrostatic levering system is used for watching the floor elevation over the long period.

Beam commissioning of the J-PARC linac DTL1 at KEK

Kondo, Yasuhiro; Akikawa, Hisashi; Anami, Shozo*; Asano, Hiroyuki*; Fukui, Yuji*; Igarashi, Zenei*; Ikegami, Kiyoshi*; Ikegami, Masanori*; Ito, Takashi; Kawamura, Masato*; et al.

Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.156 - 158, 2004/08

A commissioning of the J-PARC linac DTL1 is now under way at KEK. A 30mA H beam was accelerated to 19.7-MeV, and 100% transmission was obtained with a 20-msec-pulse-width and 12.5-Hz-repetition beam. In this paper, present status of the DTL1 commissioning and preliminary results of the commissioning, such as emittance measurements, are presented.

Effects of ships vibration and motion on plant parameters; Report on sea trials of nuclear ship MUTSU made first in Japan

Kakuta, Tsunemi; Kitamura, Toshikatsu; Mizushima, Toshihiko; ; ; ; ; ;

JAERI-M 92-034, 82 Pages, 1992/03

JAERI-M-92-034.pdf:2.36MB

no abstracts in English

Shielding Experiments for Evaluating a Shielding Safety Evaluation Code System to Spent Fuel Processing Facilities-(4)-Experiments for the Assessment on Source Gesmetry of BWR Spent Fuel Assembbies

; ; ; ; ; ; ; ; ; ; et al.

JAERI-M 84-020, 46 Pages, 1984/02

JAERI-M-84-020.pdf:1.74MB

no abstracts in English

Abnormal Transient Analysis Byusing PWR Plant SimulatorPart1:Primary Coolant System Analysis

; ;

JAERI-M 83-048, 120 Pages, 1983/03

JAERI-M-83-048.pdf:11.97MB

no abstracts in English