HB2012 - List of Authors (Mikulec, B.)

Paper

Title

Page

Beam Stability and Tail Population at SPS Scrapers

166

L.N. Drøsdal, K. Cornelis, B. Goddard, V. Kain, M. Meddahi, Ö. Mete, B. Mikulec, E. Veyrunes
CERN, Geneva, Switzerland

Before injection into the LHC the beams are scraped in the SPS to remove the tails of the transverse particle distributions. Without scraping the tail population is large enough to create losses above the beam abort thresholds of the LHC beam loss monitor system when injecting. The scrapers are only effective if correctly set up. This paper shows the results of periodical scraper scans. The beam position and beam size at the scraper is changing with time. The scraper settings hence need to follow accordingly. The scans also give insight into the transverse tail population and could therefore provide useful beam quality diagnostics. The impact on new scraper designs and setting up strategy are discussed.

MOP248

Brightness Evolution for LHC Beams during the 2012 Run

170

M. Kuhn
Uni HH, Hamburg, Germany
G. Arduini, J.F. Comblin, A. Guerrero, V. Kain, B. Mikulec, F. Roncarolo, M. Sapinski, M. Schaumann, R. Steerenberg
CERN, Geneva, Switzerland

One of the reasons for the remarkable achievements of the LHC is the excellent performance of the LHC injector chain. The evolution of the brightness in the injectors and at LHC collision in 2011 and 2012 is discussed. During certain run periods, the brightness from the beam provided by the injectors was lower than usual. Some of the issues have been identified so far and will be reported. The latest results on emittance blow-up investigations through the 2012 LHC cycle will also be presented and compared to the 2011 data. Possible implications for LHC upgrade scenarios will be mentioned.

MOP249

Tune Spread Studies at Injection Energies for the CERN Proton Synchrotron Booster

175

B. Mikulec, A. Findlay, V. Raginel, G. Rumolo, G. Sterbini
CERN, Geneva, Switzerland

In the near future, a new H⁻ injector, Linac4, will replace the current proton injector of the CERN Proton Synchrotron Booster (PSB), Linac2. The new charge-exchange injection at 160 MeV will yield higher brightness beams compared to the conventional 50 MeV multi-turn injection of Linac2. To make full use of the higher injection energy, space-charge effects will need to be understood and mitigated to optimize the intensity versus transverse emittance reach. This includes an optimization of longitudinal acceptance and distribution with a two-harmonic rf system, careful selection of the working point to accommodate the large Laslett tune-shift of approximately -0.5 and compensation of resonances within their stopbands. This paper will present calculations of the tune spread, based on measurements of longitudinal parameters and transverse emittances, for energies up to 160 MeV, different bunch densities and varying beam intensities. It should provide valuable information on the expected tune spread after the connection of Linac4 with the PSB and input for the study of resonance compensation techniques.

TUO1A01

The High Intensity/High Brightness Upgrade Program at CERN: Status and Challenges

226

S.S. Gilardoni, G. Arduini, T. Argyropoulos, S. Aumon, H. Bartosik, E. Benedetto, N. Biancacci, T. Bohl, J. Borburgh, C. Carli, F. Caspers, H. Damerau, J.F. Esteban Müller, V. Forte, R. Garoby, M. Giovannozzi, B. Goddard, S. Hancock, K. Hanke, A. Huschauer, G. Iadarola, M. Meddahi, G. Métral, B. Mikulec, E. Métral, Y. Papaphilippou, S. Persichelli, G. Rumolo, B. Salvant, F. Schmidt, E.N. Shaposhnikova, R. Steerenberg, G. Sterbini, M. Taborelli, H. Timko, M. Vretenar, R. Wasef, C. Yin Vallgren, C. Zannini
CERN, Geneva, Switzerland
G. Franchetti
GSI, Darmstadt, Germany
M. Migliorati
University of Rome "La Sapienza", Rome, Italy
A.Y. Molodozhentsev
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
M.T.F. Pivi
SLAC, Menlo Park, California, USA
V.G. Vaccaro
Naples University Federico II, Mathematical, Physical and Natural Sciences Faculty, Napoli, Italy

The future beam brilliance and intensities required by the HL-LHC (High-Luminosity LHC) project and for possible new neutrino production beams triggered a deep revision of the LHC injector performances. The analysis, progressing in the framework of the LHC Injectors Upgrade (LIU) projects, outlined major limitations mainly related to collective effects - space charge in PSB and PS, electron cloud driven and TMCI instabilities in the SPS, longitudinal coupled bunch instabilities in the PS for example - but also to the existing hardware capability to cope with beam instabilities and losses. A summary of the observations and simulation studies carried out so far, as well as the future ones, will be presented. The solution proposed to overcome the different limitations and the plans for their implementation will be also briefly reviewed.

Slides TUO1A01 [12.748 MB]

Paper	Title	Page
MOP247	Beam Stability and Tail Population at SPS Scrapers	166
	L.N. Drøsdal, K. Cornelis, B. Goddard, V. Kain, M. Meddahi, Ö. Mete, B. Mikulec, E. Veyrunes CERN, Geneva, Switzerland
	Before injection into the LHC the beams are scraped in the SPS to remove the tails of the transverse particle distributions. Without scraping the tail population is large enough to create losses above the beam abort thresholds of the LHC beam loss monitor system when injecting. The scrapers are only effective if correctly set up. This paper shows the results of periodical scraper scans. The beam position and beam size at the scraper is changing with time. The scraper settings hence need to follow accordingly. The scans also give insight into the transverse tail population and could therefore provide useful beam quality diagnostics. The impact on new scraper designs and setting up strategy are discussed.

MOP248	Brightness Evolution for LHC Beams during the 2012 Run	170
	M. Kuhn Uni HH, Hamburg, Germany G. Arduini, J.F. Comblin, A. Guerrero, V. Kain, B. Mikulec, F. Roncarolo, M. Sapinski, M. Schaumann, R. Steerenberg CERN, Geneva, Switzerland
	One of the reasons for the remarkable achievements of the LHC is the excellent performance of the LHC injector chain. The evolution of the brightness in the injectors and at LHC collision in 2011 and 2012 is discussed. During certain run periods, the brightness from the beam provided by the injectors was lower than usual. Some of the issues have been identified so far and will be reported. The latest results on emittance blow-up investigations through the 2012 LHC cycle will also be presented and compared to the 2011 data. Possible implications for LHC upgrade scenarios will be mentioned.

MOP249	Tune Spread Studies at Injection Energies for the CERN Proton Synchrotron Booster	175
	B. Mikulec, A. Findlay, V. Raginel, G. Rumolo, G. Sterbini CERN, Geneva, Switzerland
	In the near future, a new H⁻ injector, Linac4, will replace the current proton injector of the CERN Proton Synchrotron Booster (PSB), Linac2. The new charge-exchange injection at 160 MeV will yield higher brightness beams compared to the conventional 50 MeV multi-turn injection of Linac2. To make full use of the higher injection energy, space-charge effects will need to be understood and mitigated to optimize the intensity versus transverse emittance reach. This includes an optimization of longitudinal acceptance and distribution with a two-harmonic rf system, careful selection of the working point to accommodate the large Laslett tune-shift of approximately -0.5 and compensation of resonances within their stopbands. This paper will present calculations of the tune spread, based on measurements of longitudinal parameters and transverse emittances, for energies up to 160 MeV, different bunch densities and varying beam intensities. It should provide valuable information on the expected tune spread after the connection of Linac4 with the PSB and input for the study of resonance compensation techniques.

TUO1A01	The High Intensity/High Brightness Upgrade Program at CERN: Status and Challenges	226
	S.S. Gilardoni, G. Arduini, T. Argyropoulos, S. Aumon, H. Bartosik, E. Benedetto, N. Biancacci, T. Bohl, J. Borburgh, C. Carli, F. Caspers, H. Damerau, J.F. Esteban Müller, V. Forte, R. Garoby, M. Giovannozzi, B. Goddard, S. Hancock, K. Hanke, A. Huschauer, G. Iadarola, M. Meddahi, G. Métral, B. Mikulec, E. Métral, Y. Papaphilippou, S. Persichelli, G. Rumolo, B. Salvant, F. Schmidt, E.N. Shaposhnikova, R. Steerenberg, G. Sterbini, M. Taborelli, H. Timko, M. Vretenar, R. Wasef, C. Yin Vallgren, C. Zannini CERN, Geneva, Switzerland G. Franchetti GSI, Darmstadt, Germany M. Migliorati University of Rome "La Sapienza", Rome, Italy A.Y. Molodozhentsev J-PARC, KEK & JAEA, Ibaraki-ken, Japan M.T.F. Pivi SLAC, Menlo Park, California, USA V.G. Vaccaro Naples University Federico II, Mathematical, Physical and Natural Sciences Faculty, Napoli, Italy
	The future beam brilliance and intensities required by the HL-LHC (High-Luminosity LHC) project and for possible new neutrino production beams triggered a deep revision of the LHC injector performances. The analysis, progressing in the framework of the LHC Injectors Upgrade (LIU) projects, outlined major limitations mainly related to collective effects - space charge in PSB and PS, electron cloud driven and TMCI instabilities in the SPS, longitudinal coupled bunch instabilities in the PS for example - but also to the existing hardware capability to cope with beam instabilities and losses. A summary of the observations and simulation studies carried out so far, as well as the future ones, will be presented. The solution proposed to overcome the different limitations and the plans for their implementation will be also briefly reviewed.
	Slides TUO1A01 [12.748 MB]