HB2012 - List of Authors (Salvachua, B.)

Paper

Title

Page

A Tool Based on the BPM-interpolated Orbit for Speeding up LHC Collimator Alignment

162

G. Valentino, N.J. Sammut
University of Malta, Information and Communication Technology, Msida, Malta
R.W. Aßmann, R. Bruce, G.J. Müller, S. Redaelli, B. Salvachua
CERN, Geneva, Switzerland

Beam-based alignment of the LHC collimators is required in order to measure the orbit center and beam size at the collimator locations. During an alignment campaign in March 2012, 80 collimators were aligned at injection energy (450 GeV) using automatic alignment algorithms in 7.5 hours, the fastest setup time achieved since the start of LHC operation in 2008. Reducing the alignment time even further would allow for more frequent alignments, providing more time for physics operation. The proposed tool makes use of the BPM-interpolated orbit to obtain an estimation of the beam centers at the collimators, which can be exploited to quickly move the collimator jaws from the initial parking positions to tighter settings before beam-based alignment commences.

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]

WEO3C03

Beam Halo Dynamics and Control with Hollow Electron Beams

466

G. Stancari, G. Annala, A. Didenko, T.R. Johnson, I.A. Morozov, V. Previtali, G.W. Saewert, V.D. Shiltsev, D.A. Still, A. Valishev, L.G. Vorobiev
Fermilab, Batavia, USA
R.W. Aßmann, R. Bruce, S. Redaelli, A. Rossi, B. Salvachua, G. Valentino
CERN, Geneva, Switzerland
D.N. Shatilov
BINP SB RAS, Novosibirsk, Russia

Funding: Fermilab is operated by Fermi Research Alliance, LLC under Contract DE-AC02-07CH11359 with the US Department of Energy. Partial support was provided by the US LHC Accelerator Research Program (LARP).
Experimental measurements of beam halo diffusion dynamics with collimator scans are reviewed. The concept of halo control with a hollow electron beam collimator, its demonstration at the Tevatron, and its possible applications at the LHC are discussed.

Slides WEO3C03 [5.139 MB]

Paper	Title	Page
MOP246	A Tool Based on the BPM-interpolated Orbit for Speeding up LHC Collimator Alignment	162
	G. Valentino, N.J. Sammut University of Malta, Information and Communication Technology, Msida, Malta R.W. Aßmann, R. Bruce, G.J. Müller, S. Redaelli, B. Salvachua CERN, Geneva, Switzerland
	Beam-based alignment of the LHC collimators is required in order to measure the orbit center and beam size at the collimator locations. During an alignment campaign in March 2012, 80 collimators were aligned at injection energy (450 GeV) using automatic alignment algorithms in 7.5 hours, the fastest setup time achieved since the start of LHC operation in 2008. Reducing the alignment time even further would allow for more frequent alignments, providing more time for physics operation. The proposed tool makes use of the BPM-interpolated orbit to obtain an estimation of the beam centers at the collimators, which can be exploited to quickly move the collimator jaws from the initial parking positions to tighter settings before beam-based alignment commences.

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]

WEO3C03	Beam Halo Dynamics and Control with Hollow Electron Beams	466
	G. Stancari, G. Annala, A. Didenko, T.R. Johnson, I.A. Morozov, V. Previtali, G.W. Saewert, V.D. Shiltsev, D.A. Still, A. Valishev, L.G. Vorobiev Fermilab, Batavia, USA R.W. Aßmann, R. Bruce, S. Redaelli, A. Rossi, B. Salvachua, G. Valentino CERN, Geneva, Switzerland D.N. Shatilov BINP SB RAS, Novosibirsk, Russia
	Funding: Fermilab is operated by Fermi Research Alliance, LLC under Contract DE-AC02-07CH11359 with the US Department of Energy. Partial support was provided by the US LHC Accelerator Research Program (LARP). Experimental measurements of beam halo diffusion dynamics with collimator scans are reviewed. The concept of halo control with a hollow electron beam collimator, its demonstration at the Tevatron, and its possible applications at the LHC are discussed.
	Slides WEO3C03 [5.139 MB]