HB2014 - Table of Session: THO1LR (Working Group A)

Paper

Title

Page

Long-term Beam Losses in the CERN Injector Chain

325

S.S. Gilardoni, G. Arduini, H. Bartosik, E. Benedetto, H. Damerau, V. Forte, M. Giovannozzi, B. Goddard, S. Hancock, K. Hanke, A. Huschauer, M. Kowalska, M. McAteer, M. Meddahi, B. Mikulec, E. Métral, Y. Papaphilippou, G. Rumolo, E.N. Shaposhnikova, G. Sterbini, R. Wasef
CERN, Geneva, Switzerland

For the production of the LHC type beams, but also for the high intensity ones, the budget allocated to losses in the CERN injector chain is maintained as tight as possible, in particular to keep as low as possible the activation of the different machine elements. Various beam dynamics effects, like for example beam interaction with betatronic resonances, beam instabilities, but also reduced efficiency of the RF capture processes or RF noise, can produce losses even on a very long time scale. The main different mechanisms producing long term losses observed in the CERN injectors, and their cure or mitigation, will be revised.

Slides THO1LR01 [5.913 MB]

THO1LR02

Recent Commissioning of High-Intensity Proton Beams in J-PARC Main Ring

Y. Sato, T. Koseki, J. Takano, S. Yamada, N. Yamamoto
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
H. Harada, M.J. Shirakata, F. Tamura
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
S. Igarashi
KEK, Ibaraki, Japan

In the J-PARC, the main ring (MR) provides high power proton beams of 240 kW (1.24·10¹⁴ protons per pulse) to the neutrino experiment. The linac energy was upgraded from 181 MeV to 400 MeV in 2013, and its current is going to be from 30 mA to 50 mA in 2014. If the beam losses are minimized and localized in the MR, the MR will have the capability to provide over 300 kW after the upstream upgrades. Based on the upgrades and improvements of the 3-50BT and the MR in 2013 and 2014, following approaches have been tested and commissioned: 2nd harmonic RFs under the faster rise-up time improvement of the injection kickers, to increase bunching factor; intra-bunch feed-back system and chromaticity patterned correction, to suppress instability; intra-bunch feed-back, tail and reflection improvement of the injection kickers, and 6D matching between the 3-50BT and the MR, to reduce injection losses; achromatic tuning at the collimator section of the 3-50BT to cut beam halo effectively; collimator upgrades, aperture enlargement at dispersion peaks, and momentum spread control, to localize beam losses in the collimator section; new operation point survey.

Slides THO1LR02 [2.553 MB]

THO1LR03

Recent Development in the Mitigation of Long Term High Intensity Beam Loss

330

G. Franchetti, S. Aumon, F. Kesting, H. Liebermann, C. Omet, D. Ondreka, R. Singh
GSI, Darmstadt, Germany
S.S. Gilardoni, A. Huschauer, F. Schmidt, R. Wasef
CERN, Geneva, Switzerland

In this talk it is presented the state of the art studies to mitigate the long term beam loss in the FAIR accelerator. The effect of high intensity is discussed in relation with high intensities. In particular the discussion is made on the interplay of space charge with coupled machine resonance as the 3rd order. A new development in the theory of the 3rd order resonance is used to discuss the periodic crossing of resonances, hence the mitigation of the resonance effects, and experimental investigation (CERN-PS, and GSI) are addressed and interpreted.

Paper	Title	Page
THO1LR01	Long-term Beam Losses in the CERN Injector Chain	325
	S.S. Gilardoni, G. Arduini, H. Bartosik, E. Benedetto, H. Damerau, V. Forte, M. Giovannozzi, B. Goddard, S. Hancock, K. Hanke, A. Huschauer, M. Kowalska, M. McAteer, M. Meddahi, B. Mikulec, E. Métral, Y. Papaphilippou, G. Rumolo, E.N. Shaposhnikova, G. Sterbini, R. Wasef CERN, Geneva, Switzerland
	For the production of the LHC type beams, but also for the high intensity ones, the budget allocated to losses in the CERN injector chain is maintained as tight as possible, in particular to keep as low as possible the activation of the different machine elements. Various beam dynamics effects, like for example beam interaction with betatronic resonances, beam instabilities, but also reduced efficiency of the RF capture processes or RF noise, can produce losses even on a very long time scale. The main different mechanisms producing long term losses observed in the CERN injectors, and their cure or mitigation, will be revised.
	Slides THO1LR01 [5.913 MB]

THO1LR02	Recent Commissioning of High-Intensity Proton Beams in J-PARC Main Ring
	Y. Sato, T. Koseki, J. Takano, S. Yamada, N. Yamamoto J-PARC, KEK & JAEA, Ibaraki-ken, Japan H. Harada, M.J. Shirakata, F. Tamura JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan S. Igarashi KEK, Ibaraki, Japan
	In the J-PARC, the main ring (MR) provides high power proton beams of 240 kW (1.24·10¹⁴ protons per pulse) to the neutrino experiment. The linac energy was upgraded from 181 MeV to 400 MeV in 2013, and its current is going to be from 30 mA to 50 mA in 2014. If the beam losses are minimized and localized in the MR, the MR will have the capability to provide over 300 kW after the upstream upgrades. Based on the upgrades and improvements of the 3-50BT and the MR in 2013 and 2014, following approaches have been tested and commissioned: 2nd harmonic RFs under the faster rise-up time improvement of the injection kickers, to increase bunching factor; intra-bunch feed-back system and chromaticity patterned correction, to suppress instability; intra-bunch feed-back, tail and reflection improvement of the injection kickers, and 6D matching between the 3-50BT and the MR, to reduce injection losses; achromatic tuning at the collimator section of the 3-50BT to cut beam halo effectively; collimator upgrades, aperture enlargement at dispersion peaks, and momentum spread control, to localize beam losses in the collimator section; new operation point survey.
	Slides THO1LR02 [2.553 MB]

THO1LR03	Recent Development in the Mitigation of Long Term High Intensity Beam Loss	330
	G. Franchetti, S. Aumon, F. Kesting, H. Liebermann, C. Omet, D. Ondreka, R. Singh GSI, Darmstadt, Germany S.S. Gilardoni, A. Huschauer, F. Schmidt, R. Wasef CERN, Geneva, Switzerland
	In this talk it is presented the state of the art studies to mitigate the long term beam loss in the FAIR accelerator. The effect of high intensity is discussed in relation with high intensities. In particular the discussion is made on the interplay of space charge with coupled machine resonance as the 3rd order. A new development in the theory of the 3rd order resonance is used to discuss the periodic crossing of resonances, hence the mitigation of the resonance effects, and experimental investigation (CERN-PS, and GSI) are addressed and interpreted.