IPAC2014 - List of Authors (Sapinski, M.)

Paper	Title	Page
MOOCB01	Beam-induced Quench Tests of LHC Magnets	52
	M. Sapinski, B. Auchmann, T. Bär, W. Bartmann, M. Bednarek, S. Bozyigit, C. Bracco, R. Bruce, F. Cerutti, V. Chetvertkova, K. Dahlerup-Petersen, B. Dehning, E. Effinger, J. Emery, A. Guerrero, E.B. Holzer, W. Höfle, A. Lechner, A. Priebe, S. Redaelli, B. Salvachua, R. Schmidt, N.V. Shetty, A.P. Siemko, E. Skordis, M. Solfaroli Camillocci, J. Steckert, J.A. Uythoven, D. Valuch, A.P. Verweij, J. Wenninger, D. Wollmann, M. Zerlauth, E.N. del Busto CERN, Geneva, Switzerland
	At the end of the LHC Run1 a 48-hour quench-test campaign took place to investigate the quench levels of superconducting magnets for loss durations from nanoseconds to tens of seconds. The longitudinal losses produced extended from one meter to hundreds of meters and the number of lost protons varied from 10⁸ to 10¹³. The results of these and other, previously conducted quench experiments, allow the quench levels of several types of LHC magnets under various loss conditions to be assessed. The quench levels are expected to limit LHC performance in the case of steady-state losses in the interaction regions and also in the case of fast losses initiated by dust particles all around the ring. It is therefore required to accurately adjust beam loss abort thresholds in order to maximize the operation time. A detailed discussion of these quench test results and a proposal for additional tests after the LHC restart is presented.
	Slides MOOCB01 [2.737 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOOCB01
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MOPRO019	Energy Deposition and Quench Level Calculations for Millisecond and Steady-state Quench Tests of LHC Arc Quadrupoles at 4 TeV	105
	N.V. Shetty, B. Auchmann, V. Chetvertkova, A. Lechner, A. Priebe, M. Sapinski, A.P. Verweij, D. Wollmann CERN, Geneva, Switzerland
	In 2013, beam-induced quench tests with 4 TeV protons were performed to probe the quench level of LHC arc quadrupole magnets at timescales corresponding to millisecond beam losses and steady-state losses. As the energy deposition in magnet coils cannot be measured directly, this study presents corresponding FLUKA simulations as well as estimates of quench levels derived with the QP3 code. Furthermore, beam loss monitor (BLM) signals were simulated and benchmarked against the measurements. Simulated and measured BLM signals are generally found to agree within 30 percent.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO019
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MOPRO043	Handling 1 MW Losses with the LHC Collimation System	174
	B. Salvachua, R. Bruce, F. Carra, M. Cauchi, E.B. Holzer, W. Höfle, D. Jacquet, L. Lari, D. Mirarchi, E. Nebot Del Busto, S. Redaelli, A. Rossi, M. Sapinski, R. Schmidt, G. Valentino, D. Valuch, J. Wenninger, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland M. Cauchi UoM, Msida, Malta L. Lari IFIC, Valencia, Spain
	Funding: Research supported by EU FP7 HiLumi LHC (Grant agree. 284404) The LHC superconducting magnets in the dispersion suppressor of IR7 are the most exposed to beam losses leaking from the betatron collimation system and represent the main limitation for the halo cleaning. In 2013, quench tests were performed at 4 TeV to improve the quench limit estimates, which determine the maximum allowed beam loss rate for a given collimation cleaning. The main goal of the collimation quench test was to try to quench the magnets by increasing losses at the collimators. Losses of up to 1 MW over a few seconds were generated by blowing up the beam, achieving total losses of about 5.8 MJ. These controlled losses exceeded by a factor 2 the collimation design value, and the magnets did not quench.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO043
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WEPRI092	Test and Simulation Results for Quenches Induced by Fast Losses on a LHC Quadrupole	2706
	C. Bracco, B. Auchmann, W. Bartmann, M. Bednarek, A. Lechner, M. Sapinski, R. Schmidt, N.V. Shetty, M. Solfaroli Camillocci, A.P. Verweij CERN, Geneva, Switzerland
	A test program for beam induced quenches was started in the LHC in 2011 in order to reduce as much as possible BLM-triggered beam dumps, without jeopardizing the safety of the superconducting magnets. A first measurement was performed to assess the quench level of a quadrupole located in the LHC injection region in case of fast (ns) losses. It consisted in dumping single bunches onto an injection protection collimator located right upstream of the quadrupole, varying the bunch intensity up to 3·10¹⁰ protons and ramping the quadrupole current up to 2200 A. No quench was recorded at that time. The test was repeated in 2013 with increased bunch intensity (6·10¹⁰ protons); a quench occurred when powering the magnet at 2500 A. The comparison between measurements during beam induced and quench heaters induced quenches is shown. Results of FLUKA simulations on energy deposition, calculations on quench behaviour using QP3 and the respective estimates of quench levels are also presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI092
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THPRI094	MadX Tracking Simulations to Determine the Beam loss Distributions for the LHC Quench Tests with ADT Excitation	3991
	V. Chetvertkova, B. Auchmann, T. Bär, W. Höfle, A. Priebe, M. Sapinski, R. Schmidt, A.P. Verweij, D. Wollmann CERN, Geneva, Switzerland
	Quench tests with stored beam were performed in 2013 with one of the LHC main focusing quadrupoles to experimentally verify the quench levels for beam losses in the time scales from a few milliseconds to several seconds. A novel technique combining a 3-corrector orbital bump and transverse-damper kicks was used for inducing the beam losses. MadX tracking simulations were an essential step for determining the spatial and angular beam loss distributions during the experiment. These were then used as input for further energy-deposition and quench-level calculations. In this paper the simulated beam-loss distributions for the respective time scales and experimental parameters are presented. Furthermore the sensitivity of the obtained loss-distributions to the variation of key input parameters, which were measured during the experiment, is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI094
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Paper

Title

Page

Beam-induced Quench Tests of LHC Magnets

52

M. Sapinski, B. Auchmann, T. Bär, W. Bartmann, M. Bednarek, S. Bozyigit, C. Bracco, R. Bruce, F. Cerutti, V. Chetvertkova, K. Dahlerup-Petersen, B. Dehning, E. Effinger, J. Emery, A. Guerrero, E.B. Holzer, W. Höfle, A. Lechner, A. Priebe, S. Redaelli, B. Salvachua, R. Schmidt, N.V. Shetty, A.P. Siemko, E. Skordis, M. Solfaroli Camillocci, J. Steckert, J.A. Uythoven, D. Valuch, A.P. Verweij, J. Wenninger, D. Wollmann, M. Zerlauth, E.N. del Busto
CERN, Geneva, Switzerland

At the end of the LHC Run1 a 48-hour quench-test campaign took place to investigate the quench levels of superconducting magnets for loss durations from nanoseconds to tens of seconds. The longitudinal losses produced extended from one meter to hundreds of meters and the number of lost protons varied from 10⁸ to 10¹³. The results of these and other, previously conducted quench experiments, allow the quench levels of several types of LHC magnets under various loss conditions to be assessed. The quench levels are expected to limit LHC performance in the case of steady-state losses in the interaction regions and also in the case of fast losses initiated by dust particles all around the ring. It is therefore required to accurately adjust beam loss abort thresholds in order to maximize the operation time. A detailed discussion of these quench test results and a proposal for additional tests after the LHC restart is presented.

Slides MOOCB01 [2.737 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOOCB01

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRO019

Energy Deposition and Quench Level Calculations for Millisecond and Steady-state Quench Tests of LHC Arc Quadrupoles at 4 TeV

105

N.V. Shetty, B. Auchmann, V. Chetvertkova, A. Lechner, A. Priebe, M. Sapinski, A.P. Verweij, D. Wollmann
CERN, Geneva, Switzerland

In 2013, beam-induced quench tests with 4 TeV protons were performed to probe the quench level of LHC arc quadrupole magnets at timescales corresponding to millisecond beam losses and steady-state losses. As the energy deposition in magnet coils cannot be measured directly, this study presents corresponding FLUKA simulations as well as estimates of quench levels derived with the QP3 code. Furthermore, beam loss monitor (BLM) signals were simulated and benchmarked against the measurements. Simulated and measured BLM signals are generally found to agree within 30 percent.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRO043

Handling 1 MW Losses with the LHC Collimation System

174

B. Salvachua, R. Bruce, F. Carra, M. Cauchi, E.B. Holzer, W. Höfle, D. Jacquet, L. Lari, D. Mirarchi, E. Nebot Del Busto, S. Redaelli, A. Rossi, M. Sapinski, R. Schmidt, G. Valentino, D. Valuch, J. Wenninger, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland
M. Cauchi
UoM, Msida, Malta
L. Lari
IFIC, Valencia, Spain

Funding: Research supported by EU FP7 HiLumi LHC (Grant agree. 284404)
The LHC superconducting magnets in the dispersion suppressor of IR7 are the most exposed to beam losses leaking from the betatron collimation system and represent the main limitation for the halo cleaning. In 2013, quench tests were performed at 4 TeV to improve the quench limit estimates, which determine the maximum allowed beam loss rate for a given collimation cleaning. The main goal of the collimation quench test was to try to quench the magnets by increasing losses at the collimators. Losses of up to 1 MW over a few seconds were generated by blowing up the beam, achieving total losses of about 5.8 MJ. These controlled losses exceeded by a factor 2 the collimation design value, and the magnets did not quench.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO043

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRI092

Test and Simulation Results for Quenches Induced by Fast Losses on a LHC Quadrupole

2706

C. Bracco, B. Auchmann, W. Bartmann, M. Bednarek, A. Lechner, M. Sapinski, R. Schmidt, N.V. Shetty, M. Solfaroli Camillocci, A.P. Verweij
CERN, Geneva, Switzerland

A test program for beam induced quenches was started in the LHC in 2011 in order to reduce as much as possible BLM-triggered beam dumps, without jeopardizing the safety of the superconducting magnets. A first measurement was performed to assess the quench level of a quadrupole located in the LHC injection region in case of fast (ns) losses. It consisted in dumping single bunches onto an injection protection collimator located right upstream of the quadrupole, varying the bunch intensity up to 3·10¹⁰ protons and ramping the quadrupole current up to 2200 A. No quench was recorded at that time. The test was repeated in 2013 with increased bunch intensity (6·10¹⁰ protons); a quench occurred when powering the magnet at 2500 A. The comparison between measurements during beam induced and quench heaters induced quenches is shown. Results of FLUKA simulations on energy deposition, calculations on quench behaviour using QP3 and the respective estimates of quench levels are also presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI092

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRI094

MadX Tracking Simulations to Determine the Beam loss Distributions for the LHC Quench Tests with ADT Excitation

3991

V. Chetvertkova, B. Auchmann, T. Bär, W. Höfle, A. Priebe, M. Sapinski, R. Schmidt, A.P. Verweij, D. Wollmann
CERN, Geneva, Switzerland

Quench tests with stored beam were performed in 2013 with one of the LHC main focusing quadrupoles to experimentally verify the quench levels for beam losses in the time scales from a few milliseconds to several seconds. A novel technique combining a 3-corrector orbital bump and transverse-damper kicks was used for inducing the beam losses. MadX tracking simulations were an essential step for determining the spatial and angular beam loss distributions during the experiment. These were then used as input for further energy-deposition and quench-level calculations. In this paper the simulated beam-loss distributions for the respective time scales and experimental parameters are presented. Furthermore the sensitivity of the obtained loss-distributions to the variation of key input parameters, which were measured during the experiment, is discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI094

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)