Author: Ikegami, K.
Paper Title Page
TUPO079 Numerical and Experimental Study of H Beam Dynamics in J-PARC LEBT 519
TUOP10   use link to see paper's listing under its alternate paper code  
  • T. Shibata, K. Ikegami, Y. Liu, K. Ohkoshi, M. Otani
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • A. Miura, H. Oguri, K. Shinto
    JAEA/J-PARC, Tokai-mura, Japan
  • F. Naito, K. Nanmo, A. Takagi
    KEK, Tokai, Ibaraki, Japan
  Negative hydrogen ion (H) beam dynamics in J-PARC Low Energy Beam Transport (LEBT) has been investigated by numerical modeling which calculates particle transport with effect of space charge and collision processes. Understandings of H beam transport in LEBT is important for high transmission rate from Ion Source (IS) to Radio Frequency Quadrupole (RFQ) in J-PARC in higher beam current in future. In 2017, 45 mA beam current of H has been extracted from IS in J-PARC user operation which has been increased from 30 mA in last 2 years. The beam current is planned to be increased to 50 mA in the next upgrade. As the beam current increase, IS/LEBT commissioning becomes more difficult because of the higher space charge (SC). Especially in J-PARC, vacuum pressure is around 10-5 Pa by 15 mmf orifice located in the center of LEBT. The orifice prevents residual gas injection from IS to LEBT/RFQ and thus produces stronger SC effect. In the presentation, numerical results are compared with actual results from J-PARC Linac beam commissioning. A comparison of the results shows that location of the 15 mmf orifice results in two peaks of RFQ transmission rate against SOL currents.  
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DOI • reference for this paper ※  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO082 Commissioning Status of the Linac for the iBNCT Project 174
  • M. Sato, Z. Fang, M.K. Fukuda, Y. Fukui, K. Futatsukawa, Y. Honda, K. Ikegami, H. Kobayashi, C. Kubota, T. Kurihara, T. Miura, T. Miyajima, F. Naito, K. Nanmo, T. Obina, T. Shibata, T. Sugimura, A. Takagi, E. Takasaki
    KEK, Ibaraki, Japan
  • K. Hasegawa
    JAEA, Ibaraki-ken, Japan
  • H. Kumada, Y. Matsumoto, Su. Tanaka
    Tsukuba University, Graduate School of Comprehensive Human Sciences, Ibaraki, Japan
  • N. Nagura, T. Ohba
    Nippon Advanced Technology Co., Ltd., Tokai, Japan
  • T. Onishi
    Tsukuba University, Ibaraki, Japan
  • T. Ouchi, H. Sakurayama
    ATOX, Ibaraki, Japan
  Boron neutron capture therapy (BNCT) is one of the particle-beam therapies which use secondary products from a neutron capture on boron medicaments implanted into cancer cells. This has been originally studied with neutrons from nuclear reactors, meanwhile, many activities have been recently projected with accelerator-based neutron generation. In the iBNCT (Ibaraki BNCT) project, the accelerator is consisted with a radio frequency quadrupole (RFQ) and an Alvarez type drift-tube linac (DTL). Protons extracted from an ion source are accelerated up to 3 MeV and 8 MeV, respectively, and bombarded onto a beryllium target to generate neutrons. The design of the linac is based on the J-PARC one, but the most significant difference is the higher duty factor to have a sufficient epithermal neutron flux for BNCT. We have started the commissioning from the end of 2016, and the beam current of 1.3 mA with a repetition of 50 Hz has been achieved with an acceptable stability. Further beam commissioning and reinforcement of the vacuum and cooling water system will be performed toward higher beam current. In this contribution, the current status and future prospects of the linac will be presented.  
DOI • reference for this paper ※  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)