HB2016 - Table of Session: WEE1 (Working Group E

Paper	Title	Page
WEPM1X01	Performance of Linac-4 Instrumentation During Commissioning	385
	U. Raich CERN, Geneva, Switzerland
	Linac-4 is CERN’s new H⁻ Linac, which will replace the aging Linac-2 proton machine. Linac-4 is being built and commissioned in stages. While the machine is permanently equipped with the standard beam instrumentation necessary to ensure smooth operation, three dedicated measurement benches have also been designed to commission the source and LEBT at 45 keV, the MEBT and its chopper at 3 MeV as well as the first DTL tank at 12 MeV and finally the full DTL at 50 MeV and CCDTL at 100 MeV. The beam after the PIMS structures at the Linac’s full energy of 160 MeV will be sent to a beam dump and commissioned with permanently installed instruments. Installation and commissioning of the machine up to the CCDTL is now complete. This contribution will present the results from the various commissioning stages, showing the performance of the various diagnostic devices used and comparing the data obtained to simulations.
	Slides WEPM1X01 [10.600 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-HB2016-WEPM1X01
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPM2X01	High Power Target Instrumentation at J-PARC for Neutron and Muon Sources	391
	S.I. Meigo, A. Akutsu, K. Ikezaki, T.K. Kawasaki, H. Kinoshita, M. Nishikawa, M. Ooi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan H. Fujimori, S.F. Fukuta KEK/JAEA, Ibaraki-Ken, Japan
	Funding: This work is partly supported by the MEXT Grant-in-Aid for Scientific Research (C) Grant no. 26390114. At the J-PARC, spallation neutron and muon sources are injected 3-GeV proton beam with power of 1 MW extracted from 25 Hz Rapid Cycling Synchrotron (RCS). Recently several shots of the beam with equivalent power of 1 MW were successfully delivered to the targets without significant beam loss. Since the pitting erosion on the mercury target vessel utilized for spallation neutron source is known to be proportional to the 4th power of the beam current density, peak current density at the target should be kept as low as possible so that we have developed beam-flattening system by nonlinear beam optics using octupole magnets. To carry out the beam tuning efficiently, beam-tuning tool had been developed by using SAD code system. It is found that the shape of the beam can be controlled as designed. By using anti-correlated painting at the injection of the RCS, the beam was found to be shaped more flat distribution. The peak current density at the target can be reduced by 30 % with the present nonlinear optics without significant beam loss around at octupole magnets, which mitigates 76 % of the damage at the target vessel.
	Slides WEPM2X01 [9.327 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-HB2016-WEPM2X01
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPM3X01	Developments in High-Precision Fast Wire Scanners for High Intensity Proton Accelerators
	B. Dehning CERN, Geneva, Switzerland
	Wire scanners are the preferred proton beam profile measurement instruments. The scanner profile width measurement accuracy is unsurpassed and the scanners are applicable for a large beam intensity range. The transverse beam profile is sampled by the movement of a thin wire through the beam measuring impacting beam intensity and wire position. The equipment challenges are in the accurate measurement of the wire position during the high speed scan. The scan speed is maximized to cope with high intensity proton beams by limiting the energy deposition in the wire. In the contribution the operational scanner designs will be presented and their limits will be discussed. Novel approaches to overcome some limitations will be presented as well.
	Slides WEPM3X01 [2.370 MB]
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Performance of Linac-4 Instrumentation During Commissioning

385

U. Raich
CERN, Geneva, Switzerland

Linac-4 is CERN’s new H⁻ Linac, which will replace the aging Linac-2 proton machine. Linac-4 is being built and commissioned in stages. While the machine is permanently equipped with the standard beam instrumentation necessary to ensure smooth operation, three dedicated measurement benches have also been designed to commission the source and LEBT at 45 keV, the MEBT and its chopper at 3 MeV as well as the first DTL tank at 12 MeV and finally the full DTL at 50 MeV and CCDTL at 100 MeV. The beam after the PIMS structures at the Linac’s full energy of 160 MeV will be sent to a beam dump and commissioned with permanently installed instruments. Installation and commissioning of the machine up to the CCDTL is now complete. This contribution will present the results from the various commissioning stages, showing the performance of the various diagnostic devices used and comparing the data obtained to simulations.

Slides WEPM1X01 [10.600 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-HB2016-WEPM1X01

Export •

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

WEPM2X01

High Power Target Instrumentation at J-PARC for Neutron and Muon Sources

391

S.I. Meigo, A. Akutsu, K. Ikezaki, T.K. Kawasaki, H. Kinoshita, M. Nishikawa, M. Ooi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
H. Fujimori, S.F. Fukuta
KEK/JAEA, Ibaraki-Ken, Japan

Funding: This work is partly supported by the MEXT Grant-in-Aid for Scientific Research (C) Grant no. 26390114.
At the J-PARC, spallation neutron and muon sources are injected 3-GeV proton beam with power of 1 MW extracted from 25 Hz Rapid Cycling Synchrotron (RCS). Recently several shots of the beam with equivalent power of 1 MW were successfully delivered to the targets without significant beam loss. Since the pitting erosion on the mercury target vessel utilized for spallation neutron source is known to be proportional to the 4th power of the beam current density, peak current density at the target should be kept as low as possible so that we have developed beam-flattening system by nonlinear beam optics using octupole magnets. To carry out the beam tuning efficiently, beam-tuning tool had been developed by using SAD code system. It is found that the shape of the beam can be controlled as designed. By using anti-correlated painting at the injection of the RCS, the beam was found to be shaped more flat distribution. The peak current density at the target can be reduced by 30 % with the present nonlinear optics without significant beam loss around at octupole magnets, which mitigates 76 % of the damage at the target vessel.

Slides WEPM2X01 [9.327 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-HB2016-WEPM2X01

Export •

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

WEPM3X01

Developments in High-Precision Fast Wire Scanners for High Intensity Proton Accelerators

B. Dehning
CERN, Geneva, Switzerland

Wire scanners are the preferred proton beam profile measurement instruments. The scanner profile width measurement accuracy is unsurpassed and the scanners are applicable for a large beam intensity range. The transverse beam profile is sampled by the movement of a thin wire through the beam measuring impacting beam intensity and wire position. The equipment challenges are in the accurate measurement of the wire position during the high speed scan. The scan speed is maximized to cope with high intensity proton beams by limiting the energy deposition in the wire. In the contribution the operational scanner designs will be presented and their limits will be discussed. Novel approaches to overcome some limitations will be presented as well.

Slides WEPM3X01 [2.370 MB]

Export •

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