IPAC2015 - List of Authors (Kinsho, M.)

Paper	Title	Page
MOPTY003	Measurement of Momentum Spread of the Injection Beam with Longitudinal Tomography Method in the J-PARC RCS	944
	M. Yoshimoto, H. Harada, H. Hotchi, M. Kinsho, P.K. Saha, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the J-PARC RCS, the beam tuning toward the design output beam power of 1MW were started after the completing of the beam energy and beam current upgrades in the LINAC. One of the important issues to achieve the 1MW beam operation is the optimization of the injection beam from the LINAC. Due to the longitudinal beam tuning in the LINAC, the momentum spread of the injected beam into the RCS was measured with the longitudinal tomography method. Our longitudinal tomography tool had been developed using the simple algorithm with the Convolution Back-Projection (CBP) method for the beam storage mode of the RCS. Accordingly, we improved this tool to expand into the acceleration mode.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY003
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WEPMA058	New Injection Bump Power Supply of the J-PARC RCS*	2908
	T. Takayanagi, N. Hayashi, K. Horino, M. Kinsho, K. Okabe, T. Ueno JAEA/J-PARC, Tokai-mura, Japan Y. Irie KEK, Ibaraki, Japan
	The new horizontal shift bump (SB) power supply for beam injection system of the J-PARC (Japan Proton Accelerator Research Complex) 3-GeV RCS (Rapid-Cycling Synchrotron) has been developed and manufactured. The injection energy was increased from 181 MeV to 400 MeV, and the power capacity of the new power supply was doubled. The power supply newly adopted a capacitor commutation method to form the trapezoid waveform pattern (bump waveform) by the IGBT (Insulated Gate Bipolar Transistor) switch. This paper reports characteristic, the problems and the user operation status about the new shift bump power supply.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMA058
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WEPMA059	Degassing of Kicker Magnet by In-situ Bake-out Method	2911
	J. Kamiya, Y. Hikichi, M. Kinsho, N. Ogiwara JAEA/J-PARC, Tokai-mura, Japan
	New method of in-situ degassing of the kicker magnet in the beam line has been developed. The heater and heat shielding panels are installed in the vacuum chamber in this method. The heater was designed considering the maintainability. The graphite was selected as the heater and the high melting point metals were used as the reflectors just near the heater. The thermal analysis and the temperature measurement with the designed heater was performed. The ideal temperature distribution for the kicker degassing was obtained. The outgassing of the graphite during rising the temperature was measured. The result showed that the outgassing was extremely suppressed by the first heating. This means the outgassing of the graphite heater was negligible as long as it is used in the beam line without exposure to the air.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMA059
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THPF043	Preliminary Studies of Laser-assisted H⁻ Stripping at 400 MeV	3795
	P.K. Saha, H. Harada, M. Kinsho, T. Maruta, K. Okabe, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan T.V. Gorlov ORNL, Oak Ridge, Tennessee, USA Y. Irie KEK, Ibaraki, Japan
	Conventional H⁻ stripping injection by using solid stripper foils in high intensity accelerators has many limitations concerning foil scattering beam losses, short lifetime of the foil including unexpected and rapid foil failure due to overheating of the foil. It is not only an issue for reliable machine operation but also for facility maintenance. In the 3-GeV RCS of J-PARC, the residual radiation level is extremely high not only near the injection area but also the used foil itself including the foil holder even at the present operation with one third of the designed 1 MW beam power. As an alternate method, later-assisted stripping of 1 GeV H⁻ beam has been intensively studied at SNS in Oak Ridge. The preparation for the next experiment is underway to demonstrate a three orders of magnitude improvement as compared to the earlier experiment. It is important to extend these studies for the lower H⁻ beam energies. In the same framework as in the SNS, laser stripping for the J-PARC H⁻ beam energy of 400 MeV has been studied in the present work. The real challenges and feasibilities at this lower energy are discussed in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF043
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THPF044	Status of the J-PARC 3 GeV RCS	3798
	M. Kinsho JAEA/J-PARC, Tokai-mura, Japan
	Beam injection energy of the RCS in J-PARC was increased from 181 MeV to 400 MeV, and user operation with beam energy of 300 kW for both the MLF and the MR was performed with high availability from February to Jun in 2014. Beam losses during beam injection period was decreased by reduction of space charge effect due to increase of beam injection energy. Since an ion source and an RFQ of the LINAC are replaced to realize 1 MW beam power at the RCS in summer maintenance period, injection beam peak current was increased from 30 mA to 50 mA. User operation was restarted from November with beam power of 300 kW. The beam power for user operation will be gradually increased after getting radiation safety permission from government. High intensity beam study was also performed and it was successfully to accelerate beam of 770 kW equivalent without beam loss except foil scattering loss. In this beam study it was cleared issues to realize 1MW operation in the RCS. Status of user operation and issues to realize high power operation in the RCS are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF044
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Paper

Title

Page

Measurement of Momentum Spread of the Injection Beam with Longitudinal Tomography Method in the J-PARC RCS

944

M. Yoshimoto, H. Harada, H. Hotchi, M. Kinsho, P.K. Saha, F. Tamura, M. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the J-PARC RCS, the beam tuning toward the design output beam power of 1MW were started after the completing of the beam energy and beam current upgrades in the LINAC. One of the important issues to achieve the 1MW beam operation is the optimization of the injection beam from the LINAC. Due to the longitudinal beam tuning in the LINAC, the momentum spread of the injected beam into the RCS was measured with the longitudinal tomography method. Our longitudinal tomography tool had been developed using the simple algorithm with the Convolution Back-Projection (CBP) method for the beam storage mode of the RCS. Accordingly, we improved this tool to expand into the acceleration mode.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY003

Export •

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

WEPMA058

New Injection Bump Power Supply of the J-PARC RCS*

2908

T. Takayanagi, N. Hayashi, K. Horino, M. Kinsho, K. Okabe, T. Ueno
JAEA/J-PARC, Tokai-mura, Japan
Y. Irie
KEK, Ibaraki, Japan

The new horizontal shift bump (SB) power supply for beam injection system of the J-PARC (Japan Proton Accelerator Research Complex) 3-GeV RCS (Rapid-Cycling Synchrotron) has been developed and manufactured. The injection energy was increased from 181 MeV to 400 MeV, and the power capacity of the new power supply was doubled. The power supply newly adopted a capacitor commutation method to form the trapezoid waveform pattern (bump waveform) by the IGBT (Insulated Gate Bipolar Transistor) switch. This paper reports characteristic, the problems and the user operation status about the new shift bump power supply.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMA058

Export •

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

WEPMA059

Degassing of Kicker Magnet by In-situ Bake-out Method

2911

J. Kamiya, Y. Hikichi, M. Kinsho, N. Ogiwara
JAEA/J-PARC, Tokai-mura, Japan

New method of in-situ degassing of the kicker magnet in the beam line has been developed. The heater and heat shielding panels are installed in the vacuum chamber in this method. The heater was designed considering the maintainability. The graphite was selected as the heater and the high melting point metals were used as the reflectors just near the heater. The thermal analysis and the temperature measurement with the designed heater was performed. The ideal temperature distribution for the kicker degassing was obtained. The outgassing of the graphite during rising the temperature was measured. The result showed that the outgassing was extremely suppressed by the first heating. This means the outgassing of the graphite heater was negligible as long as it is used in the beam line without exposure to the air.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMA059

Export •

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

THPF043

Preliminary Studies of Laser-assisted H⁻ Stripping at 400 MeV

3795

P.K. Saha, H. Harada, M. Kinsho, T. Maruta, K. Okabe, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T.V. Gorlov
ORNL, Oak Ridge, Tennessee, USA
Y. Irie
KEK, Ibaraki, Japan

Conventional H⁻ stripping injection by using solid stripper foils in high intensity accelerators has many limitations concerning foil scattering beam losses, short lifetime of the foil including unexpected and rapid foil failure due to overheating of the foil. It is not only an issue for reliable machine operation but also for facility maintenance. In the 3-GeV RCS of J-PARC, the residual radiation level is extremely high not only near the injection area but also the used foil itself including the foil holder even at the present operation with one third of the designed 1 MW beam power. As an alternate method, later-assisted stripping of 1 GeV H⁻ beam has been intensively studied at SNS in Oak Ridge. The preparation for the next experiment is underway to demonstrate a three orders of magnitude improvement as compared to the earlier experiment. It is important to extend these studies for the lower H⁻ beam energies. In the same framework as in the SNS, laser stripping for the J-PARC H⁻ beam energy of 400 MeV has been studied in the present work. The real challenges and feasibilities at this lower energy are discussed in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF043

Export •

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

THPF044

Status of the J-PARC 3 GeV RCS

3798

M. Kinsho
JAEA/J-PARC, Tokai-mura, Japan

Beam injection energy of the RCS in J-PARC was increased from 181 MeV to 400 MeV, and user operation with beam energy of 300 kW for both the MLF and the MR was performed with high availability from February to Jun in 2014. Beam losses during beam injection period was decreased by reduction of space charge effect due to increase of beam injection energy. Since an ion source and an RFQ of the LINAC are replaced to realize 1 MW beam power at the RCS in summer maintenance period, injection beam peak current was increased from 30 mA to 50 mA. User operation was restarted from November with beam power of 300 kW. The beam power for user operation will be gradually increased after getting radiation safety permission from government. High intensity beam study was also performed and it was successfully to accelerate beam of 770 kW equivalent without beam loss except foil scattering loss. In this beam study it was cleared issues to realize 1MW operation in the RCS. Status of user operation and issues to realize high power operation in the RCS are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF044

Export •

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