IPAC2011 - List of Authors (Cruikshank, P.)

Paper	Title	Page
TUPS018	Observations of Electron Cloud Effects with the LHC Vacuum System	1560
	V. Baglin, G. Bregliozzi, P. Chiggiato, P. Cruikshank, B. Henrist, J.M. Jimenez, G. Lanza CERN, Geneva, Switzerland
	In autumn 2010, during the LHC beam commissioning, electron-cloud effects producing pressure rise in common and single vacuum beam pipes, were observed. To understand the potential limitations for future operation, dedicated machine studies were performed with beams of 50 and 75 ns bunch spacing at energy of 450 GeV. In order to push further the LHC performances, a scrubbing run was held in spring 2011. This paper summarizes the vacuum observations made during these periods. The effects of bunch intensity and different filling schemes on the vacuum levels are discussed. Simulations taking into account the effective pumping speed at the location of the vacuum gauge are introduced. As a consequence, the different vacuum levels observed along the LHC ring could be explained. Finally, the results obtained during the scrubbing run are shown together with an estimation of pressure profiles during the 2011 run.

TUPS020	Leak Tightness of LHC Cold Vacuum Systems	1566
	P. Cruikshank, S.D. Claudet, W. Maan, L. Mourier, A. Perrier-Cornet, N. Provot CERN, Geneva, Switzerland
	The cold vacuum systems of the LHC machine have been in operation since 2008. While a number of acceptable helium leaks were known to exist prior to cooldown and have not significantly evolved over the last years, several new leaks have occurred which required immediate repair activities or mitigating solutions to permit operation of the LHC. The LHC vacuum system is described together with a summary and timetable of known air and helium leaks and their impact on the functioning of the cryogenic and vacuum systems. Where leaks have been investigated and repaired, the cause and failure mechanism is described. We elaborate the mitigating solutions that have been implemented to avoid degradation of known leaks and minimize their impact on cryogenic operation and LHC availability, and finally a recall of the consolidation program to be implemented in the next LHC shutdown.

TUPS022	MedAustron Beam Vacuum System : From sources to Patient Treatment Rooms	1572
	J.M. Jimenez, P. Cruikshank, L. Faisandel, W. Maan CERN, Geneva, Switzerland T. Hauser, G. Hulla, P. Landrot, J. Wallner EBG MedAustron, Wr. Neustadt, Austria
	The MedAustron beam vacuum system is a complex system integrating different technical solutions from the source to the patient treatment rooms. The specified vacuum performances combined with the challenging integration issues require technical compromise which will be presented in this poster. The status of the design of the vacuum system will be reviewed and the pending issues will be explained.

Paper

Title

Page

Observations of Electron Cloud Effects with the LHC Vacuum System

1560

V. Baglin, G. Bregliozzi, P. Chiggiato, P. Cruikshank, B. Henrist, J.M. Jimenez, G. Lanza
CERN, Geneva, Switzerland

In autumn 2010, during the LHC beam commissioning, electron-cloud effects producing pressure rise in common and single vacuum beam pipes, were observed. To understand the potential limitations for future operation, dedicated machine studies were performed with beams of 50 and 75 ns bunch spacing at energy of 450 GeV. In order to push further the LHC performances, a scrubbing run was held in spring 2011. This paper summarizes the vacuum observations made during these periods. The effects of bunch intensity and different filling schemes on the vacuum levels are discussed. Simulations taking into account the effective pumping speed at the location of the vacuum gauge are introduced. As a consequence, the different vacuum levels observed along the LHC ring could be explained. Finally, the results obtained during the scrubbing run are shown together with an estimation of pressure profiles during the 2011 run.

TUPS020

Leak Tightness of LHC Cold Vacuum Systems

1566

P. Cruikshank, S.D. Claudet, W. Maan, L. Mourier, A. Perrier-Cornet, N. Provot
CERN, Geneva, Switzerland

The cold vacuum systems of the LHC machine have been in operation since 2008. While a number of acceptable helium leaks were known to exist prior to cooldown and have not significantly evolved over the last years, several new leaks have occurred which required immediate repair activities or mitigating solutions to permit operation of the LHC. The LHC vacuum system is described together with a summary and timetable of known air and helium leaks and their impact on the functioning of the cryogenic and vacuum systems. Where leaks have been investigated and repaired, the cause and failure mechanism is described. We elaborate the mitigating solutions that have been implemented to avoid degradation of known leaks and minimize their impact on cryogenic operation and LHC availability, and finally a recall of the consolidation program to be implemented in the next LHC shutdown.

TUPS022

MedAustron Beam Vacuum System : From sources to Patient Treatment Rooms

1572

J.M. Jimenez, P. Cruikshank, L. Faisandel, W. Maan
CERN, Geneva, Switzerland
T. Hauser, G. Hulla, P. Landrot, J. Wallner
EBG MedAustron, Wr. Neustadt, Austria

The MedAustron beam vacuum system is a complex system integrating different technical solutions from the source to the patient treatment rooms. The specified vacuum performances combined with the challenging integration issues require technical compromise which will be presented in this poster. The status of the design of the vacuum system will be reviewed and the pending issues will be explained.