HB2012 - List of Authors (Baudrenghien, P.)

Paper

Title

Page

LHC Impedance Model: Experience with High Intensity Operation in the LHC

349

B. Salvant, O. Aberle, G. Arduini, R.W. Aßmann, V. Baglin, M.J. Barnes, P. Baudrenghien, A. Bertarelli, C. Bracco, R. Bruce, X. Buffat, F. Carra, F. Caspers, G. Cattenoz, S.D. Claudet, H.A. Day, J.F. Esteban Müller, M. Garlaschè, L. Gentini, B. Goddard, A. Grudiev, B. Henrist, W. Herr, S. Jakobsen, R.J. Jones, G. Lanza, L. Lari, T. Mastoridis, N. Mounet, E. Métral, A.A. Nosych, J.L. Nougaret, S. Persichelli, T. Pieloni, A.M. Piguiet, S. Redaelli, F. Roncarolo, G. Rumolo, B. Salvachua, M. Sapinski, E.N. Shaposhnikova, L.J. Tavian, M.A. Timmins, J.A. Uythoven, A. Vidal, R. Wasef, D. Wollmann
CERN, Geneva, Switzerland
A.V. Burov
Fermilab, Batavia, USA
S.M. White
BNL, Upton, Long Island, New York, USA

The CERN Large Hadron Collider (LHC) is now in luminosity production mode and has been pushing its performance in the past months by increasing the proton beam brightness, the collision energy and the machine availability. As a consequence, collective effects have started to become more and more visible and have effectively slowed down the performance increase of the machine. Among these collective effects, the interaction of brighter LHC bunches with the longitudinal and transverse impedance of the machine has been observed to generate beam induced heating and transverse instabilities since 2010. This contribution reviews the current LHC impedance model obtained from theory, simulations and bench measurements as well as a selection of measured effects with the LHC beam.

Slides WEO1A02 [7.991 MB]

THO1C04

Performances and Future Plans of the LHC RF

565

P. Baudrenghien, T. Mastoridis
CERN, Geneva, Switzerland

The ramp-up of the LHC operation has been exceptionally fast: from the first acceleration of a single bunch at nominal intensity (1.1· E11 p) to 3.5 TeV/c on May 2010, to the accumulation of 11 fb-1 integrated luminosity two years later (June 2012). On the RF side this was made possible by a few key design choices and several developments, that allow reliable LHC operation with 0.35 A DC beam at 4 TeV/c (1380 bunches at 50 ns spacing, 1.5·10¹¹ p per bunch). This paper reviews the RF design and presents its performance. Plans are also outlined that would allow operation with 25 ns bunch spacing (doubling the beam current) and even increased bunch intensity with the target of above 1A DC current per beam, without big modification to the existing RF power system.

Slides THO1C04 [9.945 MB]

Paper	Title	Page
WEO1A02	LHC Impedance Model: Experience with High Intensity Operation in the LHC	349
	B. Salvant, O. Aberle, G. Arduini, R.W. Aßmann, V. Baglin, M.J. Barnes, P. Baudrenghien, A. Bertarelli, C. Bracco, R. Bruce, X. Buffat, F. Carra, F. Caspers, G. Cattenoz, S.D. Claudet, H.A. Day, J.F. Esteban Müller, M. Garlaschè, L. Gentini, B. Goddard, A. Grudiev, B. Henrist, W. Herr, S. Jakobsen, R.J. Jones, G. Lanza, L. Lari, T. Mastoridis, N. Mounet, E. Métral, A.A. Nosych, J.L. Nougaret, S. Persichelli, T. Pieloni, A.M. Piguiet, S. Redaelli, F. Roncarolo, G. Rumolo, B. Salvachua, M. Sapinski, E.N. Shaposhnikova, L.J. Tavian, M.A. Timmins, J.A. Uythoven, A. Vidal, R. Wasef, D. Wollmann CERN, Geneva, Switzerland A.V. Burov Fermilab, Batavia, USA S.M. White BNL, Upton, Long Island, New York, USA
	The CERN Large Hadron Collider (LHC) is now in luminosity production mode and has been pushing its performance in the past months by increasing the proton beam brightness, the collision energy and the machine availability. As a consequence, collective effects have started to become more and more visible and have effectively slowed down the performance increase of the machine. Among these collective effects, the interaction of brighter LHC bunches with the longitudinal and transverse impedance of the machine has been observed to generate beam induced heating and transverse instabilities since 2010. This contribution reviews the current LHC impedance model obtained from theory, simulations and bench measurements as well as a selection of measured effects with the LHC beam.
	Slides WEO1A02 [7.991 MB]

THO1C04	Performances and Future Plans of the LHC RF	565
	P. Baudrenghien, T. Mastoridis CERN, Geneva, Switzerland
	The ramp-up of the LHC operation has been exceptionally fast: from the first acceleration of a single bunch at nominal intensity (1.1· E11 p) to 3.5 TeV/c on May 2010, to the accumulation of 11 fb-1 integrated luminosity two years later (June 2012). On the RF side this was made possible by a few key design choices and several developments, that allow reliable LHC operation with 0.35 A DC beam at 4 TeV/c (1380 bunches at 50 ns spacing, 1.5·10¹¹ p per bunch). This paper reviews the RF design and presents its performance. Plans are also outlined that would allow operation with 25 ns bunch spacing (doubling the beam current) and even increased bunch intensity with the target of above 1A DC current per beam, without big modification to the existing RF power system.
	Slides THO1C04 [9.945 MB]