IPAC2015 - List of Authors (Futatsukawa, K.)

Paper	Title	Page
WEPMA052	Low Level RF Systems for J-PARC Linac 50-mA Operation	2889
	Z. Fang, Y. Fukui, K. Futatsukawa, T. Kobayashi, S. Michizono KEK, Ibaraki, Japan E. Chishiro, F. Sato, S. Shinozaki JAEA/J-PARC, Tokai-mura, Japan
	In the summer of 2014, lots of improvements were carried out in the J-PARC proton linac, including the ion source, the Radio Frequency Quadrupole linac (RFQ), and the medium-energy beam-transport line from the RFQ to the Drift Tube Linac (DTL) called as MEBT1. The output beam current of the ion source was upgraded from 20 to 50 mA. The previous RFQ with two RF power input ports was replaced by a newly developed RFQ with one input port. The RF power of the solid state amplifier for the rf cavities used in the MEBT1 section were upgraded; from 10 to 30 kW for both of the Buncher-1 and Buncher-2, and from 30 to 120 kW for the Chopper cavity. The old scraper used as dump of chopped beam after the Chopper cavity was also replaced by a new dump system using two scrapers; A new function of separating the chopped beam automatically to the two scrapers was developed by modifying the FPAG control program in the low level control systems. After those improvements, in the September 2014 the J-PARC linac was successfully upgraded for 50-mA beam operation. The details of the improvments, especially for the low level RF systems, will be reported in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMA052
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THPF039	Stability Studies for J-PARC Linac Upgrade to 50 mA/400 MeV	3785
	Y. Liu, T. Maruta KEK/JAEA, Ibaraki-Ken, Japan K. Futatsukawa, T. Miyao KEK, Ibaraki, Japan M. Ikegami FRIB, East Lansing, Michigan, USA A. Miura JAEA/J-PARC, Tokai-mura, Japan
	J-PARC linac applies the Equi-partitioning (EP) setting as the base-line design. And it is the first machine to adopt this approach at the design stage. EP condition is a natural solution for avoiding emittance exchange between transverse and longitudinal planes. At J-PARC linac it is also possible to explore off-EP settings. One of the motivations could be a lattice with relaxed envelope for mitigating the intra-beam stripping (IBSt) effects in high current H⁻ beam. During and after the energy upgrade in Jan., 2014 and beam current upgrade in Oct., 2014, experiments were carried out to study the stability and emittance evolution for the EP and off-EP settings with high current H⁻ beam at J-PARC linac for better choices of lattice and better understanding.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF039
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THPF040	Recent Progress of the Beam Commissioning in J-PARC Linac	3789
	T. Maruta, Y. Liu KEK/JAEA, Ibaraki-Ken, Japan K. Futatsukawa, T. Miyao KEK, Ibaraki, Japan M. Ikegami FRIB, East Lansing, Michigan, USA A. Miura JAEA/J-PARC, Tokai-mura, Japan
	J-PARC linac iis replaced the front-end in the summer shutdown in year 2014 to extend the maximum peak current to 50 mA from 30 mA. By the combination with the energy upgrade conducted in year 2013, it becomes possible to achieve the design beam energy of 133 kW, which is corresponding to 1 MW at the extraction of 3 GeV Rapid Cycling Sychrotron (RCS). The beam commissioning after the replacement started at Sep./27, and we can successfully accelerate the beam at peak current of 30 mA and 50 mA. In this presentation, we introduce the resent progress of the beam commissioning of the J-PARC linac.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF040
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Paper

Title

Page

Low Level RF Systems for J-PARC Linac 50-mA Operation

2889

Z. Fang, Y. Fukui, K. Futatsukawa, T. Kobayashi, S. Michizono
KEK, Ibaraki, Japan
E. Chishiro, F. Sato, S. Shinozaki
JAEA/J-PARC, Tokai-mura, Japan

In the summer of 2014, lots of improvements were carried out in the J-PARC proton linac, including the ion source, the Radio Frequency Quadrupole linac (RFQ), and the medium-energy beam-transport line from the RFQ to the Drift Tube Linac (DTL) called as MEBT1. The output beam current of the ion source was upgraded from 20 to 50 mA. The previous RFQ with two RF power input ports was replaced by a newly developed RFQ with one input port. The RF power of the solid state amplifier for the rf cavities used in the MEBT1 section were upgraded; from 10 to 30 kW for both of the Buncher-1 and Buncher-2, and from 30 to 120 kW for the Chopper cavity. The old scraper used as dump of chopped beam after the Chopper cavity was also replaced by a new dump system using two scrapers; A new function of separating the chopped beam automatically to the two scrapers was developed by modifying the FPAG control program in the low level control systems. After those improvements, in the September 2014 the J-PARC linac was successfully upgraded for 50-mA beam operation. The details of the improvments, especially for the low level RF systems, will be reported in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMA052

Export •

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

THPF039

Stability Studies for J-PARC Linac Upgrade to 50 mA/400 MeV

3785

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

J-PARC linac applies the Equi-partitioning (EP) setting as the base-line design. And it is the first machine to adopt this approach at the design stage. EP condition is a natural solution for avoiding emittance exchange between transverse and longitudinal planes. At J-PARC linac it is also possible to explore off-EP settings. One of the motivations could be a lattice with relaxed envelope for mitigating the intra-beam stripping (IBSt) effects in high current H⁻ beam. During and after the energy upgrade in Jan., 2014 and beam current upgrade in Oct., 2014, experiments were carried out to study the stability and emittance evolution for the EP and off-EP settings with high current H⁻ beam at J-PARC linac for better choices of lattice and better understanding.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF039

Export •

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

THPF040

Recent Progress of the Beam Commissioning in J-PARC Linac

3789

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

J-PARC linac iis replaced the front-end in the summer shutdown in year 2014 to extend the maximum peak current to 50 mA from 30 mA. By the combination with the energy upgrade conducted in year 2013, it becomes possible to achieve the design beam energy of 133 kW, which is corresponding to 1 MW at the extraction of 3 GeV Rapid Cycling Sychrotron (RCS). The beam commissioning after the replacement started at Sep./27, and we can successfully accelerate the beam at peak current of 30 mA and 50 mA. In this presentation, we introduce the resent progress of the beam commissioning of the J-PARC linac.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF040

Export •

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