HB2012 - List of Authors (Schaumann, M.)

Paper

Title

Page

Quench Tests at the Large Hadron Collider with Collimation Losses at 3.5 Z TeV

157

S. Redaelli, R.W. Aßmann, G. Bellodi, K. Brodzinski, R. Bruce, F. Burkart, M. Cauchi, D. Deboy, B. Dehning, E.B. Holzer, J.M. Jowett, E. Nebot Del Busto, M. Pojer, A. Priebe, A. Rossi, M. Sapinski, M. Schaumann, R. Schmidt, M. Solfaroli Camillocci, G. Valentino, R. Versteegen, J. Wenninger, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland
L. Lari
IFIC, Valencia, Spain

The Large Hadron Collider (LHC) has been operating since 2010 at 3.5 TeV and 4.0 TeV without experiencing quenches induced by losses from circulating beams. This situation might change at 7 TeV where the reduced margins in the superconducting magnets. The critical locations are the dispersion suppressors (DSs) at either side of the cleaning and experimental insertions, where dispersive losses are maximum. It is therefore crucial to understand in detail the quench limits with beam loss distributions alike those occurring in standard operation. In order to address this aspect, quench tests were performed by inducing large beam losses on the primary collimators of the betatron cleaning insertion, for proton and lead ion beams of 3.5 Z TeV, to probe the quench limits of the DS magnets. Losses up to 500 kW were achieved without quenches. The measurement technique and the results obtained are presented, including observations of heat loads in the cryogenics system.

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.

WEO1C06

Measurement and Simulation of Luminosity Leveling in LHC via Beam Separation

451

S. Paret, J. Qiang
LBNL, Berkeley, California, USA
R. Alemany-Fernandez, R. Calaga, R. Giachino, W. Herr, D. Jacquet, G. Papotti, T. Pieloni, L. Ponce, M. Schaumann
CERN, Geneva, Switzerland
R. Miyamoto
ESS, Lund, Sweden

Funding: This work supported by the US LHC Accelerator Research Program and the National Energy Research Scientific Computing Center of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
Leveling of the luminosity in LHC by means of separating the beams colliding at an interaction point is examined. An experiment in which the separation of the beams was stepwise increased to up to 2.5 times the beam width is presented. The luminosity at all IPs and emittance of the beams were measured to detect possible side effects of the collision with an offset. Strong-strong simulations that closely follow the experimental setup are discussed and compared with the measurements. Finally, potential alternatives for luminosity leveling are briefly described.

Slides WEO1C06 [1.031 MB]

Paper	Title	Page
MOP245	Quench Tests at the Large Hadron Collider with Collimation Losses at 3.5 Z TeV	157
	S. Redaelli, R.W. Aßmann, G. Bellodi, K. Brodzinski, R. Bruce, F. Burkart, M. Cauchi, D. Deboy, B. Dehning, E.B. Holzer, J.M. Jowett, E. Nebot Del Busto, M. Pojer, A. Priebe, A. Rossi, M. Sapinski, M. Schaumann, R. Schmidt, M. Solfaroli Camillocci, G. Valentino, R. Versteegen, J. Wenninger, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland L. Lari IFIC, Valencia, Spain
	The Large Hadron Collider (LHC) has been operating since 2010 at 3.5 TeV and 4.0 TeV without experiencing quenches induced by losses from circulating beams. This situation might change at 7 TeV where the reduced margins in the superconducting magnets. The critical locations are the dispersion suppressors (DSs) at either side of the cleaning and experimental insertions, where dispersive losses are maximum. It is therefore crucial to understand in detail the quench limits with beam loss distributions alike those occurring in standard operation. In order to address this aspect, quench tests were performed by inducing large beam losses on the primary collimators of the betatron cleaning insertion, for proton and lead ion beams of 3.5 Z TeV, to probe the quench limits of the DS magnets. Losses up to 500 kW were achieved without quenches. The measurement technique and the results obtained are presented, including observations of heat loads in the cryogenics system.

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.

WEO1C06	Measurement and Simulation of Luminosity Leveling in LHC via Beam Separation	451
	S. Paret, J. Qiang LBNL, Berkeley, California, USA R. Alemany-Fernandez, R. Calaga, R. Giachino, W. Herr, D. Jacquet, G. Papotti, T. Pieloni, L. Ponce, M. Schaumann CERN, Geneva, Switzerland R. Miyamoto ESS, Lund, Sweden
	Funding: This work supported by the US LHC Accelerator Research Program and the National Energy Research Scientific Computing Center of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Leveling of the luminosity in LHC by means of separating the beams colliding at an interaction point is examined. An experiment in which the separation of the beams was stepwise increased to up to 2.5 times the beam width is presented. The luminosity at all IPs and emittance of the beams were measured to detect possible side effects of the collision with an offset. Strong-strong simulations that closely follow the experimental setup are discussed and compared with the measurements. Finally, potential alternatives for luminosity leveling are briefly described.
	Slides WEO1C06 [1.031 MB]