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Ishizaka, Tomohisa
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.372 - 375, 2014/10
no abstracts in English
Yuri, Yosuke; Yuyama, Takahiro; Ishizaka, Tomohisa; Ishibori, Ikuo; Okumura, Susumu
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.862 - 865, 2014/10
no abstracts in English
Takahashi, Hiroki; Narita, Takahiro; Nishiyama, Koichi; Usami, Hiroki; Sakaki, Hironao; Kasugai, Atsushi; Kojima, Toshiyuki*
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.799 - 802, 2014/10
no abstracts in English
Kikuzawa, Nobuhiro; Ikeda, Hiroshi; Yoshii, Akinobu*; Kato, Yuko; Ouchi, Nobuo
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.794 - 798, 2014/10
no abstracts in English
Sawabe, Yuki; Ito, Yuichi; Kawase, Masato; Fukuta, Shimpei; Suzuki, Takahiro*; Kikuzawa, Nobuhiro; Ouchi, Nobuo
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.748 - 751, 2014/10
no abstracts in English
Oguri, Hidetomo; Hasegawa, Kazuo; Ito, Takashi; Chishiro, Etsuji; Hirano, Koichiro; Morishita, Takatoshi; Shinozaki, Shinichi; Ao, Hiroyuki; Okoshi, Kiyonori; Kondo, Yasuhiro; et al.
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.389 - 393, 2014/10
no abstracts in English
Tamura, Fumihiko; Shimada, Taihei; Yoshii, Masahito*; Omori, Chihiro*; Yamamoto, Masanobu; Nomura, Masahiro; Toda, Makoto*; Hasegawa, Katsushi*; Hara, Keigo*
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1122 - 1126, 2014/10
In the J-PARC RCS, magnetic alloy (MA) loaded rf cavities are employed to achieve a high accelerating voltage and to realize the dual harmonic operation, where a single cavity is driven by the fundamental accelerating rf and the second harmonic. The cavity is driven by a class-AB push-pull tetrode amplifier. In the dual harmonic operation, the output voltages of two tubes are unbalanced. By the unbalanced output voltage, we observe an increase of screen grid current of one of the tubes, and power consumption of the cavity tanks are also unbalanced. To balance the output voltage, high power baluns using MA cores are under development. We present the design of the baluns and test results using the RCS rf system.
Miyao, Tomoaki*; Miura, Akihiko; Kawane, Yusuke*; Ouchi, Nobuo
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.718 - 720, 2014/10
The beam energy of the J-PARC Linac is calculated by TOF (Time-of-Flight) method with the flight distance and the beam phases measured at the two phase monitors. Because the accuracy of the beam energy calculation is directly depending on the errors in the phase measurement system, all beam phase monitors are calibrated annually. We have decided to use an IQ modulator circuit to realize the high accurate calibration and to reduce the calibration time. We describe the original and new procedure of the energy calculation in this paper.
Kawane, Yusuke*; Miura, Akihiko; Miyao, Tomoaki*; Hirano, Koichiro; Sugimura, Takashi*; Kato, Yuko; Sawabe, Yuki; Fukuda, Shimpei; Ouchi, Nobuo
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1288 - 1291, 2014/10
In the J-PARC Linac, because an upgrading of a beam current up to 50mA using an RF-driven ion source and a new RFQ Linac cavity is in progress, we have developed a new frontend equipments. In order to protect the scraper against 50 mA, we need to observe the temperature and to avoid the excess heat loading of the scraper surface and to count the irradiated beam particles. We also monitor the beam transmission between the upstream and downstream of the chopper cavity to check the chopping errors using the beam current monitors. We fabricated the interlock system for the temperature, irradiated particle numbers and beam transmission. And we tested them in the test stand with actual beam. This paper describes the interlock system and their test results.
Yamamoto, Kazami; Kawase, Masato; Iwama, Yuhei; Fukuta, Shimpei; Kato, Yuko; Ouchi, Nobuo; Meigo, Shinichiro; Oi, Motoki; Kamikubota, Norihiko*
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.771 - 774, 2014/10
The radiation leak accident happened in the hadron experimental hall of J-PARC on May 23, 2013. The accident was caused by a target sublimation due to an unanticipated beam from the 50 GeV main ring (MR). To detect and prevent the radiation leakage in all facilities of J-PARC, we improve the machine protection system (MPS). In the J-PARC 3GeV synchrotron (Rapid Cycling Synchrotron, RCS), a monitoring system of an abnormal state of the extraction beam to the mercury target of material life science experiment facility (MLF) were prepared. The radiation level of the gas in the tunnel were able to always observed by connecting radiation safety system and accelerator control system. The dump temperature was included in the MPS. We also developed new interlock system that can stop the beam immediately when the beam current exceed the limit.
Hatakeyama, Shuichiro; Yoshimoto, Masahiro
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.703 - 705, 2014/10
The J-PARC LINAC introduced ACS (Annular-ring Coupled Structure) cavity and now available the 400 MeV beam extraction. As for the RCS (Rapid Cycling Synchrotron) the power supply of the injection magnets were replaced those can acceptable the 400 MeV beam injection. Because there occured many troubles of equipments in the early phase of the beam study, we desired to shorten the measurement time of the beam monitor to determine the parameters. In this report it is described the signal processing system of MWPM (Multi-wire profile monitor) which is used to measure the injection beam profile for better accuracy and shorter measurement time.
Miyawaki, Nobumasa; Fukuda, Mitsuhiro*; Kurashima, Satoshi; Kashiwagi, Hirotsugu; Okumura, Susumu; Arakawa, Kazuo*; Kamiya, Tomihiro
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1179 - 1181, 2014/10
no abstracts in English
Sawamura, Masaru; Nagai, Ryoji; Nishimori, Nobuyuki; Hajima, Ryoichi; Iwashita, Yoshihisa*; Fujisawa, Hiroshi*; Tongu, Hiromu*; Kubo, Takayuki*; Saeki, Takayuki*
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.618 - 620, 2014/10
no abstracts in English
Hajima, Ryoichi; Ferdows, M.*
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.432 - 435, 2014/10
no abstracts in English
Shinto, Katsuhiro; Ichikawa, Masahiro; Takahashi, Yasuyuki*; Kubo, Takashi*; Tsutsumi, Kazuyoshi; Kikuchi, Takayuki; Kasugai, Atsushi; Sugimoto, Masayoshi; Gobin, R.*; Girardot, P.*; et al.
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1009 - 1012, 2014/10
The prototype accelerator is being developed as an engineering validation for the International Fusion Materials Irradiation Facility (IFMIF) equipped with an accelerator-driven-type neutron source for developing fusion reactor materials. This prototype accelerator is a deuteron linear accelerator consisting of an injector, an RFQ, a superconducting linac and their auxiliaries. It aims to produce a CW D
beam with the energy and current of 9 MeV/125 mA. The injector test was completed at CEA/Saclay in 2012 for producing a CW H beam and a CW D beam with the energy and current of 100 keV/140 mA. After the beam test at CEA/Saclay, the injector was transported to the International Fusion Energy Research Centre (IFERC) located in Rokkasho, Aomori, Japan. In the end of 2013, installation of the injector was started at IFERC for the injector beam test beginning from summer 2014 in order to obtain better beam qualities to be satisfied with the injection and acceleration of the following accelerators. In this paper, some results of the injector beam test performed at CEA/Saclay and the status quo of the installation of the injector at IFERC are presented.
Nagai, Ryoji; Hajima, Ryoichi; Mori, Michiaki; Shizuma, Toshiyuki; Akagi, Tomoya*; Kosuge, Atsushi*; Honda, Yosuke*; Urakawa, Junji*
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1328 - 1331, 2014/10
A high intensity 
-ray source from the laser Compton scattering (LCS) by an electron beam in an energy-recovery linac (ERL) is a key technology for a nondestructive assay system to identify nuclear materials. In order to demonstrate accelerator and laser technologies required for a LCS photon generation, a LCS photon source is under construction at the Compact ERL (cERL). The LCS photon source consists of a mode-locked fiber laser and a laser enhancement cavity. A beamline and an experimental hatch are also under construction. The commissioning of the LCS photon source will be started in February 2015 and LCS photon generation is scheduled in March 2015.
Nagai, Ryoji; Hajima, Ryoichi; Mori, Michiaki; Shizuma, Toshiyuki; Akagi, Tomoya*; Kosuge, Atsushi*; Honda, Yosuke*; Urakawa, Junji*
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.839 - 842, 2014/10
In order to demonstrate accelerator and laser technologies required for a laser Compton scattering (LCS) photon generation, a LCS photon source is under construction at the Compact ERL (cERL). We considered the flux monitors for the adjustment LCS photon source. A thin scintillator detector and a silicon drift detector are employed as flux monitors and are installed at the upstream part of the LCS beamline. The background signal level due to the bremsstrahlung of the electron beam was measured by a CsI(pure) scintillator. In the result of the measurement, the background signal is acceptable level for the flux monitors.
Nomura, Masahiro; Yamamoto, Masanobu; Shimada, Taihei; Tamura, Fumihiko; Omori, Chihiro*; Toda, Makoto*; Hasegawa, Katsushi*; Hara, Keigo*; Yoshii, Masahito*
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1037 - 1041, 2014/10
J-PARC 3 GeV RCS and Main Ring (MR) employ RF cavities loaded with Magnetic Alloy (MA) cores. The RF cavities in RCS employ un-cut cores and the RF cavities in MR employ cut cores to increase the Q-value. In this paper, we discuss the magnetic characteristics of cut cores. At first, we show the fundamental magnetic characteristics of cut core and the influence of leakage magnetic field. Next, we discuss the relation between Rp of un-cut core and cut core. At last, we show what parameters are effective to increase the cut core Rp. Rp is a key parameter to achieve a high field gradient for increasing the beam power.
Nagai, Ryoji; Sawamura, Masaru; Nishimori, Nobuyuki; Hajima, Ryoichi
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1016 - 1018, 2014/10
In order to realize a high-brightness and monochromatic light source based on accelerator technologies, increasing of the cathode surface field of an electron gun is mandatory. Dust-free technique is a key technology to realize a high-field electron gun. We propose a new style dust-free technique. In this paper, R&D status and result of the preliminary test of the dust-free technique are reported.
Ueno, Tomoaki; Takayanagi, Tomohiro; Horino, Koki; Hayashi, Naoki; Kinsho, Michikazu
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1135 - 1138, 2014/10
In 3-GeV RCS (Rapid-Cycling Synchrotron) of J-PARC (Japan Proton Accelerator Research Complex), the beam commissioning test with 400 MeV beam injection energy from LINAC (Linear Accelerator) was started in January, 2014 and the J-PARC user operation was started in February of the year. The performance of the paint bump power supply was upgraded, which is 1.6 times the output current and 2 times the output voltage. The new power supply operation was started without a trouble on schedule. However, after the test operation of the new shift bump (SB) power supply, the trouble of the circuit part was frequent. Therefore the excitation wave pattern of the horizontal paint bump power supply, which was combined the function of the horizontal shift bump power supply pattern and the painting injection pattern, was demanded. In this paper, the contents of the upgraded power supply of the horizontal paint bump and the method of the any output wave pattern formation is reported.
