IPAC2011 - List of Authors (Sammut, N.J.)

Paper	Title	Page
TUPS037	Preliminary Assessment of Beam Impact Consequences on LHC Collimators	1617
	M. Cauchi, R.W. Assmann, A. Bertarelli, R. Bruce, F. Carra, A. Dallocchio, D. Deboy, N. Mariani, A. Rossi, N.J. Sammut CERN, Geneva, Switzerland M. Cauchi, P. Mollicone UoM, Msida, Malta L. Lari IFIC, Valencia, Spain
	The correct functioning of the LHC collimation system is crucial to attain the desired LHC luminosity performance. However, the requirements to handle high intensity beams can be demanding. In this respect, the robustness of the collimators plays an important role. An accident which causes the proton beam to hit a collimator might result in severe beam-induced damage and, in some cases, replacement of the collimator, with consequent downtime for the machine. In this paper, several case studies representing different realistic beam impact scenarios are shown. A preliminary analysis of the thermal response of tertiary collimators to beam impact is presented, from which the most critical cases can be identified. Such work will also help to give an initial insight on the operational constraints of the LHC by taking into account all relevant collimator damage limits.

THPZ034	Semi-automatic Beam-based Alignment Algorithm for the LHC Collimation System	3768
	G. Valentino, R.W. Assmann, S. Redaelli, N.J. Sammut, D. Wollmann CERN, Geneva, Switzerland G. Valentino University of Malta, Information and Communication Technology, Msida, Malta
	Full beam-based alignment of the LHC collimation system was a lengthy procedure as the collimators were set up manually. A yearly alignment campaign has been sufficient for now, although in future this may lead to a decrease in the cleaning efficiency if machine parameters such as the beam orbit drift over time. Automating the collimator setup procedure can allow for more frequent alignments, therefore reducing this risk. This paper describes the design and testing of a semi-automatic algorithm as a first step towards a fully automatic setup. Its implementation in the collimator control software and future plans are described.

THPZ035	Comparison of LHC Collimation Setups with Manual and Semi-automatic Collimator Alignment	3771
	G. Valentino, R.W. Assmann, R. Bruce, F. Burkart, M. Cauchi, D. Deboy, S. Redaelli, A. Rossi, N.J. Sammut, D. Wollmann CERN, Geneva, Switzerland G. Valentino University of Malta, Information and Communication Technology, Msida, Malta
	The LHC collimation system beam-based alignment procedure has recently been upgraded to a semi-automatic process in order to increase its efficiency. In this paper, we describe the parameters used to measure the accuracy, stability and performance of the beam-based alignment of the LHC collimation system. This is followed by a comparison of the results at 450 GeV and 3.5 TeV with (1) a manual alignment and (2) with the results for semi-automatic alignment.

Paper

Title

Page

Preliminary Assessment of Beam Impact Consequences on LHC Collimators

1617

M. Cauchi, R.W. Assmann, A. Bertarelli, R. Bruce, F. Carra, A. Dallocchio, D. Deboy, N. Mariani, A. Rossi, N.J. Sammut
CERN, Geneva, Switzerland
M. Cauchi, P. Mollicone
UoM, Msida, Malta
L. Lari
IFIC, Valencia, Spain

The correct functioning of the LHC collimation system is crucial to attain the desired LHC luminosity performance. However, the requirements to handle high intensity beams can be demanding. In this respect, the robustness of the collimators plays an important role. An accident which causes the proton beam to hit a collimator might result in severe beam-induced damage and, in some cases, replacement of the collimator, with consequent downtime for the machine. In this paper, several case studies representing different realistic beam impact scenarios are shown. A preliminary analysis of the thermal response of tertiary collimators to beam impact is presented, from which the most critical cases can be identified. Such work will also help to give an initial insight on the operational constraints of the LHC by taking into account all relevant collimator damage limits.

THPZ034

Semi-automatic Beam-based Alignment Algorithm for the LHC Collimation System

3768

G. Valentino, R.W. Assmann, S. Redaelli, N.J. Sammut, D. Wollmann
CERN, Geneva, Switzerland
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta

Full beam-based alignment of the LHC collimation system was a lengthy procedure as the collimators were set up manually. A yearly alignment campaign has been sufficient for now, although in future this may lead to a decrease in the cleaning efficiency if machine parameters such as the beam orbit drift over time. Automating the collimator setup procedure can allow for more frequent alignments, therefore reducing this risk. This paper describes the design and testing of a semi-automatic algorithm as a first step towards a fully automatic setup. Its implementation in the collimator control software and future plans are described.

THPZ035

Comparison of LHC Collimation Setups with Manual and Semi-automatic Collimator Alignment

3771

G. Valentino, R.W. Assmann, R. Bruce, F. Burkart, M. Cauchi, D. Deboy, S. Redaelli, A. Rossi, N.J. Sammut, D. Wollmann
CERN, Geneva, Switzerland
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta

The LHC collimation system beam-based alignment procedure has recently been upgraded to a semi-automatic process in order to increase its efficiency. In this paper, we describe the parameters used to measure the accuracy, stability and performance of the beam-based alignment of the LHC collimation system. This is followed by a comparison of the results at 450 GeV and 3.5 TeV with (1) a manual alignment and (2) with the results for semi-automatic alignment.