IPAC2015 - List of Authors (Auchmann, B.)

Paper	Title	Page
MOPTY055	Beam Loss Monitoring for Run 2 of the LHC	1057
	M.K. Kalliokoski, B. Auchmann, B. Dehning, F.S. Domingues Sousa, E. Effinger, J. Emery, V. Grishin, E.B. Holzer, S. Jackson, B. Kolad, E. Nebot Del Busto, O. Picha, C. Roderick, M. Sapinski, M. Sobieszek, C. Zamantzas CERN, Geneva, Switzerland
	The Beam Loss Monitoring (BLM) system of the LHC consists of over 3600 ionization chambers. The main task of the system is to prevent the superconducting magnets from quenching and protect the machine components from damage, as a result of critical beam losses. The BLM system therefore requests a beam abort when the measured dose in the chambers exceeds a threshold value. During Long Shutdown 1 (LS1) a series of modifications were made to the system. Based on the experience from Run 1 and from improved simulation models, all the threshold settings were revised, and modified where required. This was done to improve the machine safety at 7 TeV, and to reduce beam abort requests when neither a magnet quench or damage to machine components is expected. In addition to the updates of the threshold values, about 800 monitors were relocated. This improves the response to unforeseen beam losses in the millisecond time scale due to micron size dust particles present in the vacuum chamber. This contribution will discuss all the changes made to the BLM system, with the reasoning behind them.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY055
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTY045	Interactions between Macroparticles and High-Energy Proton Beams	2112
	S. Rowan, A. Apollonio, B. Auchmann, A. Lechner, O. Picha, W. Riegler, H. Schindler, R. Schmidt, F. Zimmermann CERN, Geneva, Switzerland
	A known threat to the availability of the LHC is the interaction of macroparticles (dust particles) with the LHC proton beam. At the foreseen beam energy of 6.5 TeV during Run 2, quench margins in the superconducting magnets will be 2-3 times lower, and beam losses due such interactions may result in magnet quenches. The study introduce an improved numerical model of such interactions, as well as Monte-Carlo simulations that give the probability that such events will result in a beam-dump during Run 2.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY045
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPHA016	Experimental Setups to Determine the Damage Limit of Superconducting Magnets for Instantaneous Beam Losses	3138
	V. Raginel, B. Auchmann, R. Schmidt, D. Schoerling, A.P. Verweij, D. Wollmann CERN, Geneva, Switzerland
	The damage mechanism of superconducting magnets due to the direct impact of high intensity particle beams is not well understood. Obvious candidates for upper bounds on the damage limit are overheating of insulation, and melting of the conductor. Lower bounds are obtained by the limits of elasticity in the conductor, taking into account dynamic effects (elastic stress waves). The plastic regime in between these two bounds will lead to differential thermal stress between the superconductor and stabilizer, which may lead to a permanent degradation of the magnet. An improved understanding of these mechanisms is required especially in view of the planned increase in brightness of the beams injected into the LHC and of the future High Luminosity-LHC [2] and Future Circular Collider (FCC). In this paper the plans for room temperature damage tests on critical parts of superconducting magnets and the strategy to test their damage levels at 4.3 K in the HiRadMat facility at CERN , using a 440 GeV proton beam generated by the Super Proton Synchrotron (SPS), is presented. Moreover the status of numerical simulations using FLUKA and multi-physics FEM code (ANSYS) to assess the different effect and the irradiation of the proposed experimental setup in preparation of the test is shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA016
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPHA017	Qualification of the Bypass Continuity of the Main Dipole Magnet Circuits of the LHC	3141
	S. Rowan, B. Auchmann, K. Brodzinski, Z. Charifoulline, B.I. Panev, F. Rodriguez-Mateos, I. Romera, R. Schmidt, A.P. Siemko, J. Steckert, H. Thiesen, A.P. Verweij, G.P. Willering CERN, Geneva, Switzerland H. Pfeffer Fermilab, Batavia, Illinois, USA
	The copper-stabilizer continuity measurement (CSCM) was devised in order to attain complete electrical qualification of all busbar joints, lyres, and the magnet bypass connections in the 13~kA circuits of the LHC. A CSCM is carried out at 20 K, i.e., just above the critical temperature, with resistive magnets. The circuit is then subject to an incremental series of controlled powering cycles, ultimately mimicking the decay from nominal current in the event of a magnet quench. A type test to prove the validity of such a procedure was carried out with success in April 2013, leading to the scheduling of a CSCM on all main dipole circuits up to and including 11.1 kA, i.e., the current equivalent of 6.5 TeV operation. This paper details the procedure, with respect to the type test, as well as the results and analyses of the LHC-wide qualification campaign.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPTY040	Quench Performance of the First Twin-aperture 11 T Dipole for LHC upgrades	3361
	A.V. Zlobin, N. Andreev, G. Apollinari, E.Z. Barzi, G. Chlachidze, A. Nobrega, I. Novitski, S. Stoynev, D. Turrioni Fermilab, Batavia, Illinois, USA B. Auchmann, S. Izquierdo Bermudez, M. Karppinen, L. Rossi, F. Savary, D. Smekens CERN, Geneva, Switzerland
	Funding: *Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy and European Commission under FP7 project HiLumi LHC, GA no.284404 The LHC luminosity upgrade plan foresees installation of additional collimators in Dispersion Suppressor areas around point 7 and interaction regions 1, 2 and 5. The required space for these collimators could be provided by replacing some 15-m long 8.33 T NbTi LHC main dipoles (MB) with shorter 11 T Nb3Sn dipoles (MBH) compatible with the LHC lattice and main systems. FNAL and CERN magnet groups are developing a 5.5-m long twin-aperture dipole prototype with the nominal field of 11 T at the LHC nominal current of 11.85 kA suitable for installation in the LHC. Two of these magnets with a collimator in between will replace one MB dipole. The single-aperture 2-m long dipole demonstrator and two 1-m long dipole models have been assembled and tested at FNAL in 2012-2014. The 1 m long collared coils were then assembled into the first twin-aperture Nb3Sn demonstrator dipole and tested. This paper reports test results of the first twin-aperture Nb3Sn dipole model focusing on magnet training, ramp rate sensitivity and temperature dependence of the magnet quench current. The twin-aperture dipole quench performance is compared with the data for the single-aperture models.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY040
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Beam Loss Monitoring for Run 2 of the LHC

1057

M.K. Kalliokoski, B. Auchmann, B. Dehning, F.S. Domingues Sousa, E. Effinger, J. Emery, V. Grishin, E.B. Holzer, S. Jackson, B. Kolad, E. Nebot Del Busto, O. Picha, C. Roderick, M. Sapinski, M. Sobieszek, C. Zamantzas
CERN, Geneva, Switzerland

The Beam Loss Monitoring (BLM) system of the LHC consists of over 3600 ionization chambers. The main task of the system is to prevent the superconducting magnets from quenching and protect the machine components from damage, as a result of critical beam losses. The BLM system therefore requests a beam abort when the measured dose in the chambers exceeds a threshold value. During Long Shutdown 1 (LS1) a series of modifications were made to the system. Based on the experience from Run 1 and from improved simulation models, all the threshold settings were revised, and modified where required. This was done to improve the machine safety at 7 TeV, and to reduce beam abort requests when neither a magnet quench or damage to machine components is expected. In addition to the updates of the threshold values, about 800 monitors were relocated. This improves the response to unforeseen beam losses in the millisecond time scale due to micron size dust particles present in the vacuum chamber. This contribution will discuss all the changes made to the BLM system, with the reasoning behind them.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY055

Export •

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

TUPTY045

Interactions between Macroparticles and High-Energy Proton Beams

2112

S. Rowan, A. Apollonio, B. Auchmann, A. Lechner, O. Picha, W. Riegler, H. Schindler, R. Schmidt, F. Zimmermann
CERN, Geneva, Switzerland

A known threat to the availability of the LHC is the interaction of macroparticles (dust particles) with the LHC proton beam. At the foreseen beam energy of 6.5 TeV during Run 2, quench margins in the superconducting magnets will be 2-3 times lower, and beam losses due such interactions may result in magnet quenches. The study introduce an improved numerical model of such interactions, as well as Monte-Carlo simulations that give the probability that such events will result in a beam-dump during Run 2.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY045

Export •

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

WEPHA016

Experimental Setups to Determine the Damage Limit of Superconducting Magnets for Instantaneous Beam Losses

3138

V. Raginel, B. Auchmann, R. Schmidt, D. Schoerling, A.P. Verweij, D. Wollmann
CERN, Geneva, Switzerland

The damage mechanism of superconducting magnets due to the direct impact of high intensity particle beams is not well understood. Obvious candidates for upper bounds on the damage limit are overheating of insulation, and melting of the conductor. Lower bounds are obtained by the limits of elasticity in the conductor, taking into account dynamic effects (elastic stress waves). The plastic regime in between these two bounds will lead to differential thermal stress between the superconductor and stabilizer, which may lead to a permanent degradation of the magnet. An improved understanding of these mechanisms is required especially in view of the planned increase in brightness of the beams injected into the LHC and of the future High Luminosity-LHC [2] and Future Circular Collider (FCC). In this paper the plans for room temperature damage tests on critical parts of superconducting magnets and the strategy to test their damage levels at 4.3 K in the HiRadMat facility at CERN , using a 440 GeV proton beam generated by the Super Proton Synchrotron (SPS), is presented. Moreover the status of numerical simulations using FLUKA and multi-physics FEM code (ANSYS) to assess the different effect and the irradiation of the proposed experimental setup in preparation of the test is shown.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA016

Export •

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

WEPHA017

Qualification of the Bypass Continuity of the Main Dipole Magnet Circuits of the LHC

3141

S. Rowan, B. Auchmann, K. Brodzinski, Z. Charifoulline, B.I. Panev, F. Rodriguez-Mateos, I. Romera, R. Schmidt, A.P. Siemko, J. Steckert, H. Thiesen, A.P. Verweij, G.P. Willering
CERN, Geneva, Switzerland
H. Pfeffer
Fermilab, Batavia, Illinois, USA

The copper-stabilizer continuity measurement (CSCM) was devised in order to attain complete electrical qualification of all busbar joints, lyres, and the magnet bypass connections in the 13~kA circuits of the LHC. A CSCM is carried out at 20 K, i.e., just above the critical temperature, with resistive magnets. The circuit is then subject to an incremental series of controlled powering cycles, ultimately mimicking the decay from nominal current in the event of a magnet quench. A type test to prove the validity of such a procedure was carried out with success in April 2013, leading to the scheduling of a CSCM on all main dipole circuits up to and including 11.1 kA, i.e., the current equivalent of 6.5 TeV operation. This paper details the procedure, with respect to the type test, as well as the results and analyses of the LHC-wide qualification campaign.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA017

Export •

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

WEPTY040

Quench Performance of the First Twin-aperture 11 T Dipole for LHC upgrades

3361

A.V. Zlobin, N. Andreev, G. Apollinari, E.Z. Barzi, G. Chlachidze, A. Nobrega, I. Novitski, S. Stoynev, D. Turrioni
Fermilab, Batavia, Illinois, USA
B. Auchmann, S. Izquierdo Bermudez, M. Karppinen, L. Rossi, F. Savary, D. Smekens
CERN, Geneva, Switzerland

Funding: *Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy and European Commission under FP7 project HiLumi LHC, GA no.284404
The LHC luminosity upgrade plan foresees installation of additional collimators in Dispersion Suppressor areas around point 7 and interaction regions 1, 2 and 5. The required space for these collimators could be provided by replacing some 15-m long 8.33 T NbTi LHC main dipoles (MB) with shorter 11 T Nb3Sn dipoles (MBH) compatible with the LHC lattice and main systems. FNAL and CERN magnet groups are developing a 5.5-m long twin-aperture dipole prototype with the nominal field of 11 T at the LHC nominal current of 11.85 kA suitable for installation in the LHC. Two of these magnets with a collimator in between will replace one MB dipole. The single-aperture 2-m long dipole demonstrator and two 1-m long dipole models have been assembled and tested at FNAL in 2012-2014. The 1 m long collared coils were then assembled into the first twin-aperture Nb3Sn demonstrator dipole and tested. This paper reports test results of the first twin-aperture Nb3Sn dipole model focusing on magnet training, ramp rate sensitivity and temperature dependence of the magnet quench current. The twin-aperture dipole quench performance is compared with the data for the single-aperture models.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY040

Export •

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