IPAC2013 - List of Authors (Rossi, A.)

Paper

Title

Page

Simulations and Measurements of Cleaning with 100 MJ Beams in the LHC

52

R. Bruce, R.W. Aßmann, V. Boccone, C. Bracco, M. Cauchi, F. Cerutti, D. Deboy, A. Ferrari, L. Lari, A. Marsili, A. Mereghetti, E. Quaranta, S. Redaelli, G. Robert-Demolaize, A. Rossi, B. Salvachua, E. Skordis, G. Valentino, V. Vlachoudis, Th. Weiler, D. Wollmann
CERN, Geneva, Switzerland
L. Lari
IFIC, Valencia, Spain
E. Quaranta
Politecnico/Milano, Milano, Italy
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta

The CERN Large Hadron Collider is routinely storing proton beam intensities of more than 100 MJ, which puts extraordinary demands on the control of beam losses to avoid quenches of the superconducting magnets. Therefore, a detailed understanding of the LHC beam cleaning is required. We present tracking and shower simulations of the LHC's multi-stage collimation system and compare with measured beam losses, which allow us to conclude on the predictive power of the simulations.

Slides MOODB202 [6.343 MB]

MOPWO028

Recent Developments and Future Plans for SixTrack

948

R. De Maria, R. Bruce, R. Calaga, L. Deniau, M. Fjellstrom, M. Giovannozzi, L. Lari, Y.I. Levinsen, E. McIntosh, A. Mereghetti, D. Pastor Sinuela, S. Redaelli, H. Renshall, A. Rossi, F. Schmidt, R. Tomás, V. Vlachoudis
CERN, Geneva, Switzerland
R. Appleby, D.R. Brett
UMAN, Manchester, United Kingdom
D. Banfi, J. Barranco
EPFL, Lausanne, Switzerland
B. Dalena
CEA/IRFU, Gif-sur-Yvette, France
L. Lari
IFIC, Valencia, Spain
V. Previtali
Fermilab, Batavia, USA
G. Robert-Demolaize
BNL, Upton, Long Island, New York, USA

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
SixTrack is a symplectic 6D tracking code routinely used to simulate single particle trajectories in high energy circular machines like the LHC and RHIC. The paper presents the developments recently implemented and those foreseen for extending the physics models: exact Hamiltonian, different ions and charge states, RF multipoles, non-linear fringe fields, Taylor maps, e-lenses, ion scattering. Moreover new functionalities are also added like variable number of tracked particles, time dependent strengths, GPU computations with a refactoring of the core structure. The developments will benefit studies on the LHC and SPS, for collimation efficiency, ion operations, failure scenarios and HL-LHC design.

MOPWO031

High Energy Beam Impact Tests on a LHC Tertiary Collimator at CERN HiRadMat Facility

954

M. Cauchi, O. Aberle, R.W. Aßmann, A. Bertarelli, F. Carra, A. Dallocchio, D. Deboy, L. Lari, S. Redaelli, A. Rossi
CERN, Geneva, Switzerland
M. Cauchi, P. Mollicone
UoM, Msida, Malta
L. Lari
IFIC, Valencia, Spain
N.J. Sammut
University of Malta, Information and Communication Technology, Msida, Malta

The correct functioning of the collimation system is crucial to safely operate the LHC. The requirements to handle high intensity beams can be demanding. In this respect, investigating the consequences of LHC particle beams hitting tertiary collimators (TCTs) in the experimental regions is a fundamental issue for machine protection. An experimental test was designed to investigate the robustness and effects of beam accidents on a fully assembled collimator, based on accident scenarios in the LHC. This experiment, carried out at the CERN HiRadMat (High Irradiation to Materials) facility, involved 440 GeV beam impacts of different intensities on the jaws of a horizontal TCT. This paper presents the experimental setup and the preliminary results obtained together with some first outcomes from visual inspection.

MOPWO038

Cleaning Inefficiency of the LHC Collimation System during the Energy Ramp: Simulations and Measurements

975

E. Quaranta, R. Bruce, L. Lari, D. Mirarchi, S. Redaelli, A. Rossi, B. Salvachua, G. Valentino
CERN, Geneva, Switzerland
L. Lari
IFIC, Valencia, Spain
D. Mirarchi
The Imperial College of Science, Technology and Medicine, London, United Kingdom
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta

The cleaning inefficiency of the LHC collimation system has already been studied in detail at injection and top energy (450 GeV and 4 TeV respectively). In this paper the results are presented for the cleaning inefficiency at intermediate energies, simulated using the SixTrack code. The first comparisons with measured provoked losses are discussed. This study helps in benchmarking the energy dependence of the simulated inefficiency and is thus important for the extrapolation to future operation at higher energies.

MOPWO048

Cleaning Performance of the LHC Collimation System up to 4 TeV

1002

B. Salvachua, R.W. Aßmann, R. Bruce, M. Cauchi, D. Deboy, L. Lari, A. Marsili, D. Mirarchi, E. Quaranta, S. Redaelli, A. Rossi, G. Valentino
CERN, Geneva, Switzerland
M. Cauchi
UoM, Msida, Malta
L. Lari
IFIC, Valencia, Spain
D. Mirarchi
The Imperial College of Science, Technology and Medicine, London, United Kingdom
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta

Funding: Research supported by EU FP7 HiLumi LHC (Grant agreement 284404)
In this paper we review the performance of the LHC collimation system during 2012 and compare it with previous years. During 2012, the so-called tight settings were deployed for a better cleaning and improved beta-star reach. As a result, a record cleaning efficiency below a few 0.0001 was achieved in the cold regions where the highest beam losses occur. The cleaning in other cold locations is typically a factor of 10 better. No quenches were observed during regular operation with up to 140 MJ stored beam energy. The system stability during the year, monitored regularly to ensure the system functionality for all machine configurations, and the performance of the alignment tools are also reviewed.

THPFI046

First Results of an Experiment on Advanced Collimator Materials at CERN HiRadMat Facility

3391

A. Bertarelli, O. Aberle, R.W. Aßmann, E. Berthomé, V. Boccone, M. Calderón Cueva, F. Carra, F. Cerutti, N. Charitonidis, C. Charrondière, A. Dallocchio, M. Donzé, P. Francon, M. Garlaschè, L. Gentini, M. Guinchard, N. Mariani, A. Masi, P. Moyret, S. Redaelli, A. Rossi, S.D.M. dos Santos
CERN, Geneva, Switzerland
M. Calderón Cueva
Universidad San Francisco de Quito, Cumbayá, Colombia
N. Charitonidis
EPFL, Lausanne, Switzerland
L. Peroni, M. Scapin
Politecnico di Torino, Torino, Italy

Funding: The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement no. 227579
A comprehensive, first-of-its-kind experiment (HRMT-14) has been recently carried out at CERN HiRadMat facility on six different materials of interest for Beam Intercepting Devices (collimators, targets, dumps). Both traditional materials (Mo, W and Cu alloys) as well as advanced metal/diamond and metal/graphite composites were tested under extreme conditions as to pressure, density and temperature, leading to the development of highly dynamic phenomena as shock-waves, spallation, explosions. Experimental data were acquired, mostly in real time, relying on extensive embarked instrumentation (strain gauges, temperature and vacuum sensors) and on remote acquisition devices (laser Doppler vibrometer and high speed camera). The experiment was a success under all points of view in spite of the technological challenges and harsh environment. First measurements are in good agreement with results of complex simulations, confirming the effectiveness of the acquisition system and the reliability of advanced numerical methods when material constitutive models are completely available. Interesting information has been collected as to thermal shock robustness of tested materials.

Paper	Title	Page
MOODB202	Simulations and Measurements of Cleaning with 100 MJ Beams in the LHC	52
	R. Bruce, R.W. Aßmann, V. Boccone, C. Bracco, M. Cauchi, F. Cerutti, D. Deboy, A. Ferrari, L. Lari, A. Marsili, A. Mereghetti, E. Quaranta, S. Redaelli, G. Robert-Demolaize, A. Rossi, B. Salvachua, E. Skordis, G. Valentino, V. Vlachoudis, Th. Weiler, D. Wollmann CERN, Geneva, Switzerland L. Lari IFIC, Valencia, Spain E. Quaranta Politecnico/Milano, Milano, Italy G. Valentino University of Malta, Information and Communication Technology, Msida, Malta
	The CERN Large Hadron Collider is routinely storing proton beam intensities of more than 100 MJ, which puts extraordinary demands on the control of beam losses to avoid quenches of the superconducting magnets. Therefore, a detailed understanding of the LHC beam cleaning is required. We present tracking and shower simulations of the LHC's multi-stage collimation system and compare with measured beam losses, which allow us to conclude on the predictive power of the simulations.
	Slides MOODB202 [6.343 MB]

MOPWO028	Recent Developments and Future Plans for SixTrack	948
	R. De Maria, R. Bruce, R. Calaga, L. Deniau, M. Fjellstrom, M. Giovannozzi, L. Lari, Y.I. Levinsen, E. McIntosh, A. Mereghetti, D. Pastor Sinuela, S. Redaelli, H. Renshall, A. Rossi, F. Schmidt, R. Tomás, V. Vlachoudis CERN, Geneva, Switzerland R. Appleby, D.R. Brett UMAN, Manchester, United Kingdom D. Banfi, J. Barranco EPFL, Lausanne, Switzerland B. Dalena CEA/IRFU, Gif-sur-Yvette, France L. Lari IFIC, Valencia, Spain V. Previtali Fermilab, Batavia, USA G. Robert-Demolaize BNL, Upton, Long Island, New York, USA
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. SixTrack is a symplectic 6D tracking code routinely used to simulate single particle trajectories in high energy circular machines like the LHC and RHIC. The paper presents the developments recently implemented and those foreseen for extending the physics models: exact Hamiltonian, different ions and charge states, RF multipoles, non-linear fringe fields, Taylor maps, e-lenses, ion scattering. Moreover new functionalities are also added like variable number of tracked particles, time dependent strengths, GPU computations with a refactoring of the core structure. The developments will benefit studies on the LHC and SPS, for collimation efficiency, ion operations, failure scenarios and HL-LHC design.

MOPWO031	High Energy Beam Impact Tests on a LHC Tertiary Collimator at CERN HiRadMat Facility	954
	M. Cauchi, O. Aberle, R.W. Aßmann, A. Bertarelli, F. Carra, A. Dallocchio, D. Deboy, L. Lari, S. Redaelli, A. Rossi CERN, Geneva, Switzerland M. Cauchi, P. Mollicone UoM, Msida, Malta L. Lari IFIC, Valencia, Spain N.J. Sammut University of Malta, Information and Communication Technology, Msida, Malta
	The correct functioning of the collimation system is crucial to safely operate the LHC. The requirements to handle high intensity beams can be demanding. In this respect, investigating the consequences of LHC particle beams hitting tertiary collimators (TCTs) in the experimental regions is a fundamental issue for machine protection. An experimental test was designed to investigate the robustness and effects of beam accidents on a fully assembled collimator, based on accident scenarios in the LHC. This experiment, carried out at the CERN HiRadMat (High Irradiation to Materials) facility, involved 440 GeV beam impacts of different intensities on the jaws of a horizontal TCT. This paper presents the experimental setup and the preliminary results obtained together with some first outcomes from visual inspection.

MOPWO038	Cleaning Inefficiency of the LHC Collimation System during the Energy Ramp: Simulations and Measurements	975
	E. Quaranta, R. Bruce, L. Lari, D. Mirarchi, S. Redaelli, A. Rossi, B. Salvachua, G. Valentino CERN, Geneva, Switzerland L. Lari IFIC, Valencia, Spain D. Mirarchi The Imperial College of Science, Technology and Medicine, London, United Kingdom G. Valentino University of Malta, Information and Communication Technology, Msida, Malta
	The cleaning inefficiency of the LHC collimation system has already been studied in detail at injection and top energy (450 GeV and 4 TeV respectively). In this paper the results are presented for the cleaning inefficiency at intermediate energies, simulated using the SixTrack code. The first comparisons with measured provoked losses are discussed. This study helps in benchmarking the energy dependence of the simulated inefficiency and is thus important for the extrapolation to future operation at higher energies.

MOPWO048	Cleaning Performance of the LHC Collimation System up to 4 TeV	1002
	B. Salvachua, R.W. Aßmann, R. Bruce, M. Cauchi, D. Deboy, L. Lari, A. Marsili, D. Mirarchi, E. Quaranta, S. Redaelli, A. Rossi, G. Valentino CERN, Geneva, Switzerland M. Cauchi UoM, Msida, Malta L. Lari IFIC, Valencia, Spain D. Mirarchi The Imperial College of Science, Technology and Medicine, London, United Kingdom G. Valentino University of Malta, Information and Communication Technology, Msida, Malta
	Funding: Research supported by EU FP7 HiLumi LHC (Grant agreement 284404) In this paper we review the performance of the LHC collimation system during 2012 and compare it with previous years. During 2012, the so-called tight settings were deployed for a better cleaning and improved beta-star reach. As a result, a record cleaning efficiency below a few 0.0001 was achieved in the cold regions where the highest beam losses occur. The cleaning in other cold locations is typically a factor of 10 better. No quenches were observed during regular operation with up to 140 MJ stored beam energy. The system stability during the year, monitored regularly to ensure the system functionality for all machine configurations, and the performance of the alignment tools are also reviewed.

THPFI046	First Results of an Experiment on Advanced Collimator Materials at CERN HiRadMat Facility	3391
	A. Bertarelli, O. Aberle, R.W. Aßmann, E. Berthomé, V. Boccone, M. Calderón Cueva, F. Carra, F. Cerutti, N. Charitonidis, C. Charrondière, A. Dallocchio, M. Donzé, P. Francon, M. Garlaschè, L. Gentini, M. Guinchard, N. Mariani, A. Masi, P. Moyret, S. Redaelli, A. Rossi, S.D.M. dos Santos CERN, Geneva, Switzerland M. Calderón Cueva Universidad San Francisco de Quito, Cumbayá, Colombia N. Charitonidis EPFL, Lausanne, Switzerland L. Peroni, M. Scapin Politecnico di Torino, Torino, Italy
	Funding: The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement no. 227579 A comprehensive, first-of-its-kind experiment (HRMT-14) has been recently carried out at CERN HiRadMat facility on six different materials of interest for Beam Intercepting Devices (collimators, targets, dumps). Both traditional materials (Mo, W and Cu alloys) as well as advanced metal/diamond and metal/graphite composites were tested under extreme conditions as to pressure, density and temperature, leading to the development of highly dynamic phenomena as shock-waves, spallation, explosions. Experimental data were acquired, mostly in real time, relying on extensive embarked instrumentation (strain gauges, temperature and vacuum sensors) and on remote acquisition devices (laser Doppler vibrometer and high speed camera). The experiment was a success under all points of view in spite of the technological challenges and harsh environment. First measurements are in good agreement with results of complex simulations, confirming the effectiveness of the acquisition system and the reliability of advanced numerical methods when material constitutive models are completely available. Interesting information has been collected as to thermal shock robustness of tested materials.