IPAC2014 - List of Authors (Okamura, M.)

Paper	Title	Page
MOPRI010	Laser Ablation Ion Source for the KEK Digital Accelerator	598
	N. Munemoto Department of Energy Sciences, Tokyo Institute of Technology, Yokohama, Japan Y. Fuwa, S. Ikeda, M. Kumaki RIKEN, Saitama, Japan Y. Fuwa Kyoto ICR, Uji, Kyoto, Japan S. Ikeda, K. Takayama TIT, Yokohama, Japan M. Kumaki RISE, Tokyo, Japan M. Okamura BNL, Upton, Long Island, New York, USA S. Takano, K. Takayama KEK, Ibaraki, Japan K. Takayama Sokendai, Ibaraki, Japan
	KEK Digital Accelerator (DA) is a small scale induction synchrotron and operated at 10Hz and recently has succeeded to accelerate gaseous ions. There is a strong demand of fully striped carbon ions because the DA is regarded as the second generation of cancer therapy driver, which does not require an injector and electron stripper. We need a novel carbon ion source providing C⁶⁺ beams, which are directly injected into the DA and accelerated up to required energy. For this purpose, a laser ablation ion source(LAIS) is promising. To obtain high yield C⁶⁺ ions from ablation plasma, the laser irradiation condition has been evaluated and relationship between beam properties of charge spectrum, intensity, and temperature, and carbon target materials were examined. Two laser systems, long pulse (6 ns) and short pulse (170 ps), were employed to irradiate a graphite and amorphous carbon target. The current densities and profile of the generated plasmas in time were measured and charge state distributions were analyzed. In addition we will report a full design integrating this LAIS, the extraction system, the longitudinal chopper system, and the low energy beam transport line. T.Yoshimoto et al., presented in this conference ** N.Munemoto et al., Proceedings of ICIS2013, published in Rev. Sci. Inst.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI010
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MOPRI011	Control of Plasma Flux with Pulsed Solenoid for Laser Ion Source	601
SUSPSNE027	use link to see paper's listing under its alternate paper code
	S. Ikeda, K. Horioka TIT, Yokohama, Japan Y. Fuwa, S. Ikeda, M. Kumaki RIKEN, Saitama, Japan T. Kanesue, M. Okamura BNL, Upton, Long Island, New York, USA
	We discuss the behavior of laser-ablation plasma spreading through a pulsed solenoidal field to minimize the beam emittance of laser-ablation ion source (LIS). LIS is expected to produce high-flux and low emittance ion beams from various solid materials in vacuum because of the high drift velocity and low temperature of the ablation plasma due to the adiabatic expansion. However, the ion flux level from the ablation plasma into an extraction gap changes within a pulse and then the shape of the sheath boundary changes transiently. Then, the integrated emittance is larger than the stroboscopic emittance at a certain time slice. To prevent the transient effect, we tried to control the plasma flux with a pulsed solenoidal magnetic field. The field is expected to change the direction of the plasma flow like a lens. By changing the magnetic flux density according to the transient flux level of ablation plasma, we can expect to control the plasma flux at the extraction gap. To investigate the controllability of the plasma flow, we measured the plasma flux as a function of parameters of the pulsed magnetic field. We scanned ion probes along the beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI011
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WEOAB01	The Commissioning of the Laser Ion Source for RHIC-EBIS	1890
	T. Kanesue, J.G. Alessi, E.N. Beebe, M.R. Costanzo, L. DeSanto, R.F. Lambiase, D. Lehn, C.J. Liaw, V. LoDestro, M. Okamura, R.H. Olsen, A.I. Pikin, D. Raparia, A.N. Steszyn BNL, Upton, Long Island, New York, USA S. Ikeda TIT, Yokohama, Japan K. Kondo, M. Sekine RLNR, Tokyo, Japan
	Funding: Work supported by NASA and Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy A new laser ion source (LIS) for low charge state ion production was installed on RHIC-EBIS. This is the first LIS to be combined with an Electron Beam Ion Source (EBIS) type heavy ion source. The LIS provides intense low charge state ions from any solid state material, with low emittance and narrow pulse length. These features make it suitable as an external source of 1+ ions that can be injected into the EBIS trap for charge breeding. In addition, a LIS is the only type ion source which can allow rapid switching among many ion species, even on pulse-by-pulse basis, by changing either laser path or target position, to strike the material of choice. The EBIS works as a charge breeder, with the extracted high charge state ions used in the following accelerators. The beams from LIS will be used for RHIC and NASA Space Radiation Laboratory (NSRL) at BNL. The rapid beam switching, which was not possible with existing ion sources, will expand the research field at NSRL as a galactic cosmic ray simulator. The results of commissioning will be shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEOAB01
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Paper

Title

Page

Laser Ablation Ion Source for the KEK Digital Accelerator

598

N. Munemoto
Department of Energy Sciences, Tokyo Institute of Technology, Yokohama, Japan
Y. Fuwa, S. Ikeda, M. Kumaki
RIKEN, Saitama, Japan
Y. Fuwa
Kyoto ICR, Uji, Kyoto, Japan
S. Ikeda, K. Takayama
TIT, Yokohama, Japan
M. Kumaki
RISE, Tokyo, Japan
M. Okamura
BNL, Upton, Long Island, New York, USA
S. Takano, K. Takayama
KEK, Ibaraki, Japan
K. Takayama
Sokendai, Ibaraki, Japan

KEK Digital Accelerator (DA) is a small scale induction synchrotron and operated at 10Hz and recently has succeeded to accelerate gaseous ions*. There is a strong demand of fully striped carbon ions because the DA is regarded as the second generation of cancer therapy driver, which does not require an injector and electron stripper. We need a novel carbon ion source providing C⁶⁺ beams, which are directly injected into the DA and accelerated up to required energy. For this purpose, a laser ablation ion source(LAIS) is promising**. To obtain high yield C⁶⁺ ions from ablation plasma, the laser irradiation condition has been evaluated and relationship between beam properties of charge spectrum, intensity, and temperature, and carbon target materials were examined. Two laser systems, long pulse (6 ns) and short pulse (170 ps), were employed to irradiate a graphite and amorphous carbon target. The current densities and profile of the generated plasmas in time were measured and charge state distributions were analyzed. In addition we will report a full design integrating this LAIS, the extraction system, the longitudinal chopper system, and the low energy beam transport line.
* T.Yoshimoto et al., presented in this conference
** N.Munemoto et al., Proceedings of ICIS2013, published in Rev. Sci. Inst.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI010

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MOPRI011

Control of Plasma Flux with Pulsed Solenoid for Laser Ion Source

601

SUSPSNE027

use link to see paper's listing under its alternate paper code

S. Ikeda, K. Horioka
TIT, Yokohama, Japan
Y. Fuwa, S. Ikeda, M. Kumaki
RIKEN, Saitama, Japan
T. Kanesue, M. Okamura
BNL, Upton, Long Island, New York, USA

We discuss the behavior of laser-ablation plasma spreading through a pulsed solenoidal field to minimize the beam emittance of laser-ablation ion source (LIS). LIS is expected to produce high-flux and low emittance ion beams from various solid materials in vacuum because of the high drift velocity and low temperature of the ablation plasma due to the adiabatic expansion. However, the ion flux level from the ablation plasma into an extraction gap changes within a pulse and then the shape of the sheath boundary changes transiently. Then, the integrated emittance is larger than the stroboscopic emittance at a certain time slice. To prevent the transient effect, we tried to control the plasma flux with a pulsed solenoidal magnetic field. The field is expected to change the direction of the plasma flow like a lens. By changing the magnetic flux density according to the transient flux level of ablation plasma, we can expect to control the plasma flux at the extraction gap. To investigate the controllability of the plasma flow, we measured the plasma flux as a function of parameters of the pulsed magnetic field. We scanned ion probes along the beam.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI011

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

WEOAB01

The Commissioning of the Laser Ion Source for RHIC-EBIS

1890

T. Kanesue, J.G. Alessi, E.N. Beebe, M.R. Costanzo, L. DeSanto, R.F. Lambiase, D. Lehn, C.J. Liaw, V. LoDestro, M. Okamura, R.H. Olsen, A.I. Pikin, D. Raparia, A.N. Steszyn
BNL, Upton, Long Island, New York, USA
S. Ikeda
TIT, Yokohama, Japan
K. Kondo, M. Sekine
RLNR, Tokyo, Japan

Funding: Work supported by NASA and Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
A new laser ion source (LIS) for low charge state ion production was installed on RHIC-EBIS. This is the first LIS to be combined with an Electron Beam Ion Source (EBIS) type heavy ion source. The LIS provides intense low charge state ions from any solid state material, with low emittance and narrow pulse length. These features make it suitable as an external source of 1+ ions that can be injected into the EBIS trap for charge breeding. In addition, a LIS is the only type ion source which can allow rapid switching among many ion species, even on pulse-by-pulse basis, by changing either laser path or target position, to strike the material of choice. The EBIS works as a charge breeder, with the extracted high charge state ions used in the following accelerators. The beams from LIS will be used for RHIC and NASA Space Radiation Laboratory (NSRL) at BNL. The rapid beam switching, which was not possible with existing ion sources, will expand the research field at NSRL as a galactic cosmic ray simulator. The results of commissioning will be shown.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEOAB01

Export •

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