LINAC2018 - List of Authors (Obina, T.)

Paper	Title	Page
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 ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO082
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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TU1P03	Observation of Resonant Coherent Diffraction Radiation from a Multi-bunch Electron Beam Passing Through an Optical Cavity
	Y. Honda, A. Aryshev, R. Kato, T. Miyajima, T. Obina, M. Shimada, R. Takai, T. Uchiyama, N. Yamamoto KEK, Ibaraki, Japan T. Hotei Sokendai, Ibaraki, Japan
	Funding: This work was supported by JSPS KAKENHI Grant Number 16H05991. Energy Recovery Linac can realize a linac-type beam at a high current. An ERL test accelerator, cERL, has been constructed in KEK. Utilizing these features of the ERL beam, low emittance, short bunch, and high repetition rate, we have been developing a unique terahertz radiation source of resonant coherent diffraction radiation. An optical resonant cavity consists of two concave mirrors with a beam hole at the center was installed in the return-loop of cERL. When the multi-bunch electron beam passes through the cavity, it radiates coherent diffraction radiation in the cavity. If the round-trip time of the cavity precisely matches the beam repetition, the radiation of the bunches are stacked coherently and stimulates the energy conversion process from the beam to the radiation. Measuring the terahertz radiation power while scanning the cavity length, we observed a sharp resonance peak showing the realization of the stimulated emission. The cavity was carefully designed to tune the carrier-envelope-offset to be zero. It allows to excite wide-band longitudinal modes simultaneously, and realize a mode-locked terahertz pulse.
	Slides TU1P03 [1.740 MB]
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Paper

Title

Page

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 ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO082

About •

paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU1P03

Observation of Resonant Coherent Diffraction Radiation from a Multi-bunch Electron Beam Passing Through an Optical Cavity

Y. Honda, A. Aryshev, R. Kato, T. Miyajima, T. Obina, M. Shimada, R. Takai, T. Uchiyama, N. Yamamoto
KEK, Ibaraki, Japan
T. Hotei
Sokendai, Ibaraki, Japan

Funding: This work was supported by JSPS KAKENHI Grant Number 16H05991.
Energy Recovery Linac can realize a linac-type beam at a high current. An ERL test accelerator, cERL, has been constructed in KEK. Utilizing these features of the ERL beam, low emittance, short bunch, and high repetition rate, we have been developing a unique terahertz radiation source of resonant coherent diffraction radiation. An optical resonant cavity consists of two concave mirrors with a beam hole at the center was installed in the return-loop of cERL. When the multi-bunch electron beam passes through the cavity, it radiates coherent diffraction radiation in the cavity. If the round-trip time of the cavity precisely matches the beam repetition, the radiation of the bunches are stacked coherently and stimulates the energy conversion process from the beam to the radiation. Measuring the terahertz radiation power while scanning the cavity length, we observed a sharp resonance peak showing the realization of the stimulated emission. The cavity was carefully designed to tune the carrier-envelope-offset to be zero. It allows to excite wide-band longitudinal modes simultaneously, and realize a mode-locked terahertz pulse.

Slides TU1P03 [1.740 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)