General overview of the research project investigating the radionuclide solution behavior in mock mortar matrix modeled after conditions at the Fukushima-Daiichi Nuclear Power Station

Igarashi, Go*; Haga, Kazuko*; Yamada, Kazuo*; Aihara, Haruka; Shibata, Atsuhiro; Koma, Yoshikazu; Maruyama, Ippei*

Journal of Advanced Concrete Technology, 19(9), p.950 - 976, 2021/09

https://doi.org/10.3151/jact.19.950

New project on the analysis of contamination mechanisms of concrete at the Fukushima Daiichi Nuclear Power Station

Yamada, Kazuo*; Maruyama, Ippei*; Koma, Yoshikazu; Haga, Kazuko*; Igarashi, Go*; Shibuya, Kazutoshi*; Aihara, Haruka

Proceedings of International Waste Management Symposia 2019 (WM2019) (CD-ROM), 6 Pages, 2019/03

Beam loss detected by scintillation monitor

Miura, Akihiko; Maruta, Tomofumi; Sako, Hiroyuki; Hasegawa, Kazuo; Ouchi, Nobuo; Igarashi, Zenei*; Miyao, Tomoaki*; Ikegami, Masanori*

Proceedings of 2nd International Particle Accelerator Conference (IPAC 2011) (Internet), p.1257 - 1259, 2011/09

http://accelconf.web.cern.ch/AccelConf/IPAC2011/papers/tupc104.pdf

Ar-CO gas proportional beam loss monitors (BLMs) have measured the beam loss through operations, but they are also sensitive to background noise of X-ray emitted from RF cavities. For the future energy upgrade of J-PARC linac, because 21 RF cavities are additionally installed in the beam line, the background noise would be serious problem. We employed the scintillation monitors to measure the beam loss which would bring more accurate beam loss measurements with suppression of X-ray noise. As the measurement results, a good signal to noise ratio is observed for the scintillation monitor with quite low sensitivity to the background X-ray. In addition, the availability of the scintillation monitor is also confirmed at the low energy part. This paper describes the beam loss measurement system using a scintillation monitor.

Beam loss detection by scintillation monitor

Miura, Akihiko; Maruta, Tomofumi; Sako, Hiroyuki; Hasegawa, Kazuo; Ouchi, Nobuo; Igarashi, Zenei*; Miyao, Tomoaki*; Ikegami, Masanori*

Proceedings of 8th Annual Meeting of Particle Accelerator Society of Japan (Internet), 3 Pages, 2011/08

http://www.pasj.jp/web_publish/pasj8/proceedings/poster/MOPS077.pdf

Ar-CO gas proportional beam loss monitors (BLMs) have measured the beam loss through operations, but they are also sensitive to background noise of X-ray emitted from RF cavities. For the future energy upgrade of J-PARC linac, because 21 RF cavities are additionally installed in the beam line, the background noise would be serious problem. We employed the scintillation monitors to measure the beam loss which would bring more accurate beam loss measurements with suppression of X-ray noise. As the measurement results, a good signal to noise ratio is observed for the scintillation monitor with quite low sensitivity to the background X-ray. This paper describes the beam loss measurement system using a scintillation monitor.

Design of beam diagnostic systems for energy upgraded linac

Miura, Akihiko; Sato, Susumu; Sako, Hiroyuki; Yoshikawa, Hiroshi; Hasegawa, Kazuo; Igarashi, Zenei*; Ikegami, Masanori*

Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.733 - 735, 2010/03

http://www.pasj.jp/web_publish/pasj6/papers/tobdc01.pdf

no abstracts in English

Commissioning strategies for J-PARC linac and L3BT

Ikegami, Masanori*; Lee, S.*; Akikawa, Hisashi*; Igarashi, Zenei*; Kondo, Yasuhiro; Okawa, Tomohiro; Ueno, Akira; Sako, Hiroyuki; Ao, Hiroyuki; Sato, Susumu; et al.

KEK Proceedings 2006-15 (CD-ROM), p.347 - 349, 2007/03

We plan to start the beam commissioning of J-PARC linac with reduced energy of 181 MeV in the end of this year. Detailed commissioning strategies for the linac and the succeeding beam transport line, to which we refer as L3BT or Linac-to-3-GeV-synchrotron Beam Transport, will be presented in this talk. The emphasis will be put on the commissioning procedures for two debuncher cavities and a transverse collimator system located in L3BT, because they are key elements in determining the final beam quality at the injection point to the succeeding 3-GeV synchrotron. The unique design and features of the collimator system are also presented.

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.

Systematic calibration of beam position monitor in the high intensity proton accelerator (J-PARC) linac

Sato, Susumu; Igarashi, Zenei*; Lee, S.*; Tomisawa, Tetsuo; Hiroki, Fumio; Kishiro, Junichi; Ikegami, Masanori*; Kondo, Yasuhiro; Hasegawa, Kazuo; Ueno, Akira; et al.

Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004), p.429 - 431, 2004/00

As a joint project of KEK and JAERI, a MW class of high intensity proton accelerator (J-PARC), consisting of Linac, 3 GeV-RCS, 50 GeV-MR, is under construction at Tokai, Japan. For this accelerator, it is required to minimize the beam loss (typically, lower than 0.11 W/m at the linac). To achieve the requirement, beam trajectory needs to be controlled with accuracy of some 100 micro-meter. The first stage of the acceleration (up to 181 MeV during the first stage of construction) is done by linac. The beam position monitor (BPM) in the linac utilizes 4 strip-line pickups (50 ohm) on the beam transportation chamber. In this paper, systematic calibration of the BPM is described.

Dynamic properties of lithium ions in lithium ceramics

Igawa, Naoki; Ono, Hideo; Nagasaki, Takanori; Ishii, Yoshinobu; Noda, Kenji; Watanabe, H.; Matsuo, Toru*; Igarashi, Kazuo*

Ceramic Transactions, Vol.27, p.135 - 156, 1992/00

no abstracts in English

Study on the radionuclide contamination mechanisms of concrete and the estimation of distribution of radionuclides, 10; Modeling of penetration behavior of Cs and Sr into concrete at turbine building basement of Fukushima Daiichi Nuclear Power Station

Tomita, Sayuri*; Kobayashi, Yutaro*; Haga, Kazuko*; Hosokawa, Yoshifumi*; Yamada, Kazuo*; Aihara, Haruka; Igarashi, Go*; Maruyama, Ippei*

no journal, , 

no abstracts in English