IPAC2018 - List of Authors (Maruta, T.)

Paper	Title	Page
TUPAK008	Longitudinal Bunch Size Measurements with an RF Deflector at J-PARC LINAC	974
	M. Otani, K. Futatsukawa KEK, Ibaraki, Japan K. Hirano, A. Miura JAEA/J-PARC, Tokai-mura, Japan Y. Liu KEK/JAEA, Ibaraki-Ken, Japan T. Maruta FRIB, East Lansing, USA
	Measurement of the longitudinal bunch size is important for the stable beam operation. Especially in a medium energy beam transport (MEBT) located after a radio-frequency quadrupole in J-PARC, it is necessary to measure the bunch size with minimum set of equipment to avoid subsequent emittance growth due to space charge. We had proposed a longitudinal size measurement with an rf deflector normally used for deflecting theμbunch; phase spread is migrated to spatial one if the reference particle arrives at the deflector when the voltage is rising in time and is zero. Then a buncher cavity located upstream of the deflector is utilized to scan the phase spread to measure the longitudinal beam parameters. In this poster, recent measurement results are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAK008
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TUPAL040	Ion Beam Studies in the FRIB Front End	1094
	T. Yoshimoto, K. Fukushima, S.M. Lidia, T. Maruta, P.N. Ostroumov, G. Pozdeyev, H.T. Ren FRIB, East Lansing, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 and the National Science Foundation under Cooperative Agreement PHY-1102511. The commissioning of the FRIB Front End with 12 keV/u argon beam started in the spring of 2017. Beam profile monitors were used to evaluate RMS Twiss parameters in various locations along the beam line. Beam dynamics in the LEBT was simulated using full 3D model of beam optics elements in the tracking codes. We found a good consistency between measured and simulated data. A beam image viewer was used to measure the beam density distribution in the real space. A hollow beam structure was observed in the Ar⁹⁺ beam with the current of ~20 eμA. Extensive beam dynamics study with 3D tracking code suggests that the hollow density distribution can be generated by space charge effects of the multi-component, multi-charge state ion beam just after the ECR ion source. This paper reports studies of a mechanism that can produce a hollow beam structure. E. Pozdeyev, invited talk at this conference
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL040
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THYGBF4	Accelerator Physics Advances in FRIB (Facility for Rare Isotope Beams)	2950
	P.N. Ostroumov, N.K. Bultman, M. Ikegami, S.M. Lidia, S.M. Lund, G. Machicoane, T. Maruta, A.S. Plastun, G. Pozdeyev, X. Rao, J. Wei, T. Xu, T. Yoshimoto, Q. Zhao FRIB, East Lansing, USA C.Y. Wong NSCL, East Lansing, Michigan, USA
	Funding: Work supported by the U.S. DOE Office of Science under Cooperative Agreement DE-SC0000661 and the NSF under Cooperative Agreement PHY-1102511, the State of Michigan and Michigan State University. This paper presents recent developments of accelerator physics related topics for the Facility for Rare Isotope Beams (FRIB) being built at Michigan State University. While extensive beam dynamics simulations including all known errors do not show uncontrolled beam losses in the linac, ion beam contaminants extracted from the ECR ion source together with main ion beam can produce significant losses after the charge stripper. These studies resulted in development of beam collimation system at relatively low energy of 16 MeV/u and room temperature bunchers instead of originally planned superconducting ones. Commissioning of the Front End enabled detailed beam physics studies accompanied with the simulations using several beam dynamics codes. Settings of beam optics devices from the ECR to MEBT has been developed and applied to meet important project milestones. Similar work is planned for the beam commissioning of the first 3 cryomodules in the superconducting linac.
	Slides THYGBF4 [11.092 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THYGBF4
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Paper

Title

Page

Longitudinal Bunch Size Measurements with an RF Deflector at J-PARC LINAC

974

M. Otani, K. Futatsukawa
KEK, Ibaraki, Japan
K. Hirano, A. Miura
JAEA/J-PARC, Tokai-mura, Japan
Y. Liu
KEK/JAEA, Ibaraki-Ken, Japan
T. Maruta
FRIB, East Lansing, USA

Measurement of the longitudinal bunch size is important for the stable beam operation. Especially in a medium energy beam transport (MEBT) located after a radio-frequency quadrupole in J-PARC, it is necessary to measure the bunch size with minimum set of equipment to avoid subsequent emittance growth due to space charge. We had proposed a longitudinal size measurement with an rf deflector normally used for deflecting theμbunch; phase spread is migrated to spatial one if the reference particle arrives at the deflector when the voltage is rising in time and is zero. Then a buncher cavity located upstream of the deflector is utilized to scan the phase spread to measure the longitudinal beam parameters. In this poster, recent measurement results are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAK008

Export •

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

TUPAL040

Ion Beam Studies in the FRIB Front End

1094

T. Yoshimoto, K. Fukushima, S.M. Lidia, T. Maruta, P.N. Ostroumov, G. Pozdeyev, H.T. Ren
FRIB, East Lansing, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 and the National Science Foundation under Cooperative Agreement PHY-1102511.
The commissioning of the FRIB Front End with 12 keV/u argon beam started in the spring of 2017*. Beam profile monitors were used to evaluate RMS Twiss parameters in various locations along the beam line. Beam dynamics in the LEBT was simulated using full 3D model of beam optics elements in the tracking codes. We found a good consistency between measured and simulated data. A beam image viewer was used to measure the beam density distribution in the real space. A hollow beam structure was observed in the Ar⁹⁺ beam with the current of ~20 eμA. Extensive beam dynamics study with 3D tracking code suggests that the hollow density distribution can be generated by space charge effects of the multi-component, multi-charge state ion beam just after the ECR ion source. This paper reports studies of a mechanism that can produce a hollow beam structure.
*E. Pozdeyev, invited talk at this conference

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL040

Export •

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

THYGBF4

Accelerator Physics Advances in FRIB (Facility for Rare Isotope Beams)

2950

P.N. Ostroumov, N.K. Bultman, M. Ikegami, S.M. Lidia, S.M. Lund, G. Machicoane, T. Maruta, A.S. Plastun, G. Pozdeyev, X. Rao, J. Wei, T. Xu, T. Yoshimoto, Q. Zhao
FRIB, East Lansing, USA
C.Y. Wong
NSCL, East Lansing, Michigan, USA

Funding: Work supported by the U.S. DOE Office of Science under Cooperative Agreement DE-SC0000661 and the NSF under Cooperative Agreement PHY-1102511, the State of Michigan and Michigan State University.
This paper presents recent developments of accelerator physics related topics for the Facility for Rare Isotope Beams (FRIB) being built at Michigan State University. While extensive beam dynamics simulations including all known errors do not show uncontrolled beam losses in the linac, ion beam contaminants extracted from the ECR ion source together with main ion beam can produce significant losses after the charge stripper. These studies resulted in development of beam collimation system at relatively low energy of 16 MeV/u and room temperature bunchers instead of originally planned superconducting ones. Commissioning of the Front End enabled detailed beam physics studies accompanied with the simulations using several beam dynamics codes. Settings of beam optics devices from the ECR to MEBT has been developed and applied to meet important project milestones. Similar work is planned for the beam commissioning of the first 3 cryomodules in the superconducting linac.

Slides THYGBF4 [11.092 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THYGBF4

Export •

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