IPAC2014 - List of Authors (Schmidt, R.)

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
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)

MOPME045	Overview on the Design of the Machine Protection System for ESS	472
	A. Nordt ESS, Lund, Sweden A. Apollonio, R. Schmidt CERN, Geneva, Switzerland
	Scope of the Machine Protection System (MPS) for the European Spallation Source (ESS) is to protect equipment located in the accelerator, target station, neutron instruments and conventional facilities, from damage induced by beam losses or malfunctioning equipment. The MPS design function is to inhibit beam production within a few microseconds for the fastest failures at a safety integrity level of SIL2 according to the IEC61508 standard. These requirements result from a hazard and risk analysis being performed for the all systems at ESS. In a next step the architecture and topology of the distributed machine interlock system has been developed and will be presented. At the same time as MPS seeks to protect equipment it must protect the beam by avoiding triggering false stops of beam production, leading to unnecessary downtime of the ESS facility.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME045
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPME047	Comparison of the Results of a Hydrodynamic Tunneling Experiment with Iterative FLUKA and BIG2 Simulations	479
	F. Burkart, J. Blanco, D. Grenier, R. Schmidt, D. Wollmann CERN, Geneva, Switzerland N.A. Tahir GSI, Darmstadt, Germany
	In 2012, a novel experiment has been performed at the CERN HiRadMat facility to study the impact of a 440 GeV proton beam generated by the Super Proton Synchrotron (SPS), on extended solid copper cylindrical targets. Substantial hydrodynamic tunneling of the protons in the target material has been observed. Iterative FLUKA and BIG2 simulations with the parameters of the actual experiment have been performed. In this paper the results of these simulations will be discussed and compared to the experimental measurements. Furthermore, the implication on the machine protection design for high intensity hadron accelerators as the current LHC and the future High Luminosity LHC will be addressed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME047
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRO015	Update on Predictions for Yearly Integrated Luminosity for HL-LHC based on Expected Machine Availability	1036
	A. Apollonio, M. Jonker, R. Schmidt, B. Todd, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland
	Machine availability is one of the key performance indicators to reach the ambitious goals for integrated luminosity in the post Long Shutdown 1 (LS1) era. Machine availability is even more important for the future High Luminosity LHC (HL-LHC) [1]. In this paper a Monte Carlo approach has been used to predict integrated luminosity as a function of LHC machine availability. The baseline model assumptions such as fault-time distributions and machine failure rate (number of fills with stable beams dumped after a failure / total number of fills with stable beams) were deduced from the observations during LHC operation in 2012. The predictions focus on operation after LS1 and its evolution towards HL-LHC. The extrapolation of relevant parameters impacting on machine availability is outlined and their corresponding impact on fault time distributions is discussed. Results for possible future operational scenarios are presented. Finally, a sensitivity analysis with relevant model parameters like fault time and machine failure rate is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO015
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRO016	Machine Protection Challenges for HL-LHC	1039
	R. Schmidt, T. Bär, J. Wenninger, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland
	LHC operation requires the flawless functioning of the machine protection systems. The energy stored in the beam was progressively increased beyond the 140 MJ range at the end of 2012 at 4 TeV/c. The further increase to 364 MJ expected for 2015 at 6.5 TeV/c should be possible with the existing protection systems. For HL-LHC, additional failure modes are considered. The stored beam energy will increase by another factor of two with respect to nominal and a factor of five more than experienced so far. The maximum beta function will increase. It is planned to install crab cavities in the LHC. With crab cavities, sudden voltage decays within 100 us after e.g. cavity quenches lead to large beam oscillations. Tracking simulations predict trajectory distortions of up to 1.5 σ in the first turn after a sudden drop of the deflecting voltage in a single cavity within 3 turns. The energy of several MJ stored in halo protons that could hit the collimator in case of such events is far above damage level, even if the collimator jaws are made of robust material. In this paper we discuss the challenges for machine protection in the HL-LHC era and possible mitigation strategies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO016
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)

THPRO117	Infrastructure Controls Integration at ESS	3168
	D.P. Piso, J. Lundgren, M. Reščič, R. Sjöholm ESS, Lund, Sweden T. Ranstorp ÅF, Malmö, Sweden R. Schmidt CERN, Geneva, Switzerland
	The European Spallation Source (ESS) project is starting the construction of buildings June 2014. When the access to linac tunnel and gallery building is ready, the commissioning of the first sections of the accelerator starts. A proper operation of the machine relies on the services provided by different infrastructure systems (water cooling, electrical power system, ventilation, etc.) These systems will be used long before beam operation starts and need to be operated via the Integrated Control System (ICS) from the Control Room. Due to the number and variety of these systems, their heterogeneous characteristics and the different teams of designers, the integration process into ICS is challenging. Experience in other facilities [2,3] shows that a late integration produces higher maintenance and operation costs, and even impact on the reliability of the machine. This paper presents the strategy developed by two partners, the Controls and Conventional Facilities Division (CF). It is planned to capture the requirements for the interfaces and to ensure an early integration of Infrastructure Systems into the EPICS environment. First results of this approach are shown for some systems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO117
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRO118	A PLC Test Bench at ESS	3171
	D.P. Piso, M. Reščič ESS, Lund, Sweden G. Cijan Cosylab, Ljubljana, Slovenia R. Schmidt CERN, Geneva, Switzerland
	The European Spallation Source (ESS) is an accelerator- driven neutron spallation source. The Integrated Controls Systems (ICS) is responsible for providing control and mon- itoring for all parts of the machine (accelerator, target, neu- tron scattering systems and conventional facilities) [1]. A large number of applications have been identified across all parts of the facility where PLCs will be used: cryogenics, vacuum, water-cooling, power systems, safety and protec- tion systems. The Controls Division at ESS is deploying a PLC Test Bench. The motivation is to evaluate different technologies, to test PLCs and their integration into EPICS, to prototype control systems and use the test bench as PLC software development platform. This report defines the ar- chitecture of this infrastructure. The first stage to procure a first set of hardware and to perform initial tests has already been finished, consisting of a comparison between the per- formance of the s7plc EPICS driver and the Modbus EPICS driver. The results of these tests are discussed and future plans for this infrastructure are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO118
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPME172	Experimental Results from the Characterization of Diamond Particle Detectors with a High Intensity Electron Beam	3671
	F. Burkart, R. Schmidt, O. Stein, D. Wollmann CERN, Geneva, Switzerland E. Griesmayer CIVIDEC Instrumentation, Wien, Austria
	Understanding the sources of ultra-fast failures, with durations of less than 3 LHC turns, is important for a safe operation of the LHC, as only passive protection is possible in these time scales. Diamond particle detectors with bunch-by-bunch resolution and high dynamic range have been successfully used to improve the understanding of some new ultra-fast loss mechanisms discovered in the LHC. To fully exploit their potential, diamond detectors were characterized with a high-intensity electron beam (10⁵ to 1010 electrons per shot). For the first time their efficiency and linearity has been measured in such a wide range of intensities. In this paper the experimental setup will be described and the signals of the different detectors will be discussed. Finally, future applications of these detectors in high-radiation applications will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME172
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRI019	Reliability and Availability Modeling for Accelerator Driven Facilities	3803
	O. Rey Orozko, E. Bargalló, A. Nordt ESS, Lund, Sweden A. Apollonio, R. Schmidt CERN, Geneva, Switzerland
	Accelerator driven facilities are and will have to be designed to a very high level of reliability and beam availability to meet expectations of the users and experiments. In order to fulfill these demanding requirements on reliability and overall beam availability, statistical models have been developed. We compare different statistical reliability models as well as tools in terms of their performance, capacity and user-friendliness. In addition we also benchmarked some of the existing models. We will present in detail a tool being used for LHC and LINAC4 which is based on the commercially available software package Isograph and a tool using Excel, which was developed in house for ESS-systems. The impact of an early reliability modeling on the design of mission critical systems will be presented as well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRI093	CSCM: EXPERIMENTAL AND SIMULATION RESULTS	3988
	S. Rowan, B. Auchmann, K. Brodzinski, Z. Charifoulline, R. Denz, V. Roger, I. Romera, R. Schmidt, A.P. Siemko, J. Steckert, H. Thiesen, A.P. Verweij, G.P. Willering, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland H. Pfeffer Fermilab, Batavia, Illinois, USA
	The copper-stabilizer continuity measurement - or CSCM - was devised to obtain a direct and complete qualification of the continuity in the 13 kA bypass circuits of the LHC, especially in the copper-stabilizer of the busbar joints and the bolted connections in the diode-leads. The circuit under test is brought to ~20 K, a voltage is applied to open the diodes, and the low-inductance circuit is powered with a pre-defined series of current profiles. The profiles are designed to successively increase the thermal load on the busbar joints up to a level that corresponds to worst-case operating conditions at nominal energy. In this way, the circuit is tested for thermal runaways in the joints - the very process that could prove catastrophic if it occurred under nominal conditions with the full circuit energy. Surveillance software and a numerical model were devised to carry out the analysis and ensure complete protection of the circuit from over-heating. A type test of the CSCM was successfully carried out in April 2013 on one main dipole and one main quadrupole circuit of the LHC. This paper describes the analysis procedure, the numerical model, and results of this first type test.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI093
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)

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)

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)

MOPME045

Overview on the Design of the Machine Protection System for ESS

472

A. Nordt
ESS, Lund, Sweden
A. Apollonio, R. Schmidt
CERN, Geneva, Switzerland

Scope of the Machine Protection System (MPS) for the European Spallation Source (ESS) is to protect equipment located in the accelerator, target station, neutron instruments and conventional facilities, from damage induced by beam losses or malfunctioning equipment. The MPS design function is to inhibit beam production within a few microseconds for the fastest failures at a safety integrity level of SIL2 according to the IEC61508 standard. These requirements result from a hazard and risk analysis being performed for the all systems at ESS. In a next step the architecture and topology of the distributed machine interlock system has been developed and will be presented. At the same time as MPS seeks to protect equipment it must protect the beam by avoiding triggering false stops of beam production, leading to unnecessary downtime of the ESS facility.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME045

Export •

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

MOPME047

Comparison of the Results of a Hydrodynamic Tunneling Experiment with Iterative FLUKA and BIG2 Simulations

479

F. Burkart, J. Blanco, D. Grenier, R. Schmidt, D. Wollmann
CERN, Geneva, Switzerland
N.A. Tahir
GSI, Darmstadt, Germany

In 2012, a novel experiment has been performed at the CERN HiRadMat facility to study the impact of a 440 GeV proton beam generated by the Super Proton Synchrotron (SPS), on extended solid copper cylindrical targets. Substantial hydrodynamic tunneling of the protons in the target material has been observed. Iterative FLUKA and BIG2 simulations with the parameters of the actual experiment have been performed. In this paper the results of these simulations will be discussed and compared to the experimental measurements. Furthermore, the implication on the machine protection design for high intensity hadron accelerators as the current LHC and the future High Luminosity LHC will be addressed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME047

Export •

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

TUPRO015

Update on Predictions for Yearly Integrated Luminosity for HL-LHC based on Expected Machine Availability

1036

A. Apollonio, M. Jonker, R. Schmidt, B. Todd, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland

Machine availability is one of the key performance indicators to reach the ambitious goals for integrated luminosity in the post Long Shutdown 1 (LS1) era. Machine availability is even more important for the future High Luminosity LHC (HL-LHC) [1]. In this paper a Monte Carlo approach has been used to predict integrated luminosity as a function of LHC machine availability. The baseline model assumptions such as fault-time distributions and machine failure rate (number of fills with stable beams dumped after a failure / total number of fills with stable beams) were deduced from the observations during LHC operation in 2012. The predictions focus on operation after LS1 and its evolution towards HL-LHC. The extrapolation of relevant parameters impacting on machine availability is outlined and their corresponding impact on fault time distributions is discussed. Results for possible future operational scenarios are presented. Finally, a sensitivity analysis with relevant model parameters like fault time and machine failure rate is discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO015

Export •

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

TUPRO016

Machine Protection Challenges for HL-LHC

1039

R. Schmidt, T. Bär, J. Wenninger, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland

LHC operation requires the flawless functioning of the machine protection systems. The energy stored in the beam was progressively increased beyond the 140 MJ range at the end of 2012 at 4 TeV/c. The further increase to 364 MJ expected for 2015 at 6.5 TeV/c should be possible with the existing protection systems. For HL-LHC, additional failure modes are considered. The stored beam energy will increase by another factor of two with respect to nominal and a factor of five more than experienced so far. The maximum beta function will increase. It is planned to install crab cavities in the LHC. With crab cavities, sudden voltage decays within 100 us after e.g. cavity quenches lead to large beam oscillations. Tracking simulations predict trajectory distortions of up to 1.5 σ in the first turn after a sudden drop of the deflecting voltage in a single cavity within 3 turns. The energy of several MJ stored in halo protons that could hit the collimator in case of such events is far above damage level, even if the collimator jaws are made of robust material. In this paper we discuss the challenges for machine protection in the HL-LHC era and possible mitigation strategies.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO016

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)

THPRO117

Infrastructure Controls Integration at ESS

3168

D.P. Piso, J. Lundgren, M. Reščič, R. Sjöholm
ESS, Lund, Sweden
T. Ranstorp
ÅF, Malmö, Sweden
R. Schmidt
CERN, Geneva, Switzerland

The European Spallation Source (ESS) project is starting the construction of buildings June 2014. When the access to linac tunnel and gallery building is ready, the commissioning of the first sections of the accelerator starts. A proper operation of the machine relies on the services provided by different infrastructure systems (water cooling, electrical power system, ventilation, etc.) These systems will be used long before beam operation starts and need to be operated via the Integrated Control System (ICS) from the Control Room. Due to the number and variety of these systems, their heterogeneous characteristics and the different teams of designers, the integration process into ICS is challenging. Experience in other facilities [2,3] shows that a late integration produces higher maintenance and operation costs, and even impact on the reliability of the machine. This paper presents the strategy developed by two partners, the Controls and Conventional Facilities Division (CF). It is planned to capture the requirements for the interfaces and to ensure an early integration of Infrastructure Systems into the EPICS environment. First results of this approach are shown for some systems.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO117

Export •

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

THPRO118

A PLC Test Bench at ESS

3171

D.P. Piso, M. Reščič
ESS, Lund, Sweden
G. Cijan
Cosylab, Ljubljana, Slovenia
R. Schmidt
CERN, Geneva, Switzerland

The European Spallation Source (ESS) is an accelerator- driven neutron spallation source. The Integrated Controls Systems (ICS) is responsible for providing control and mon- itoring for all parts of the machine (accelerator, target, neu- tron scattering systems and conventional facilities) [1]. A large number of applications have been identified across all parts of the facility where PLCs will be used: cryogenics, vacuum, water-cooling, power systems, safety and protec- tion systems. The Controls Division at ESS is deploying a PLC Test Bench. The motivation is to evaluate different technologies, to test PLCs and their integration into EPICS, to prototype control systems and use the test bench as PLC software development platform. This report defines the ar- chitecture of this infrastructure. The first stage to procure a first set of hardware and to perform initial tests has already been finished, consisting of a comparison between the per- formance of the s7plc EPICS driver and the Modbus EPICS driver. The results of these tests are discussed and future plans for this infrastructure are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO118

Export •

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

THPME172

Experimental Results from the Characterization of Diamond Particle Detectors with a High Intensity Electron Beam

3671

F. Burkart, R. Schmidt, O. Stein, D. Wollmann
CERN, Geneva, Switzerland
E. Griesmayer
CIVIDEC Instrumentation, Wien, Austria

Understanding the sources of ultra-fast failures, with durations of less than 3 LHC turns, is important for a safe operation of the LHC, as only passive protection is possible in these time scales. Diamond particle detectors with bunch-by-bunch resolution and high dynamic range have been successfully used to improve the understanding of some new ultra-fast loss mechanisms discovered in the LHC. To fully exploit their potential, diamond detectors were characterized with a high-intensity electron beam (10⁵ to 1010 electrons per shot). For the first time their efficiency and linearity has been measured in such a wide range of intensities. In this paper the experimental setup will be described and the signals of the different detectors will be discussed. Finally, future applications of these detectors in high-radiation applications will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME172

Export •

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

THPRI019

Reliability and Availability Modeling for Accelerator Driven Facilities

3803

O. Rey Orozko, E. Bargalló, A. Nordt
ESS, Lund, Sweden
A. Apollonio, R. Schmidt
CERN, Geneva, Switzerland

Accelerator driven facilities are and will have to be designed to a very high level of reliability and beam availability to meet expectations of the users and experiments. In order to fulfill these demanding requirements on reliability and overall beam availability, statistical models have been developed. We compare different statistical reliability models as well as tools in terms of their performance, capacity and user-friendliness. In addition we also benchmarked some of the existing models. We will present in detail a tool being used for LHC and LINAC4 which is based on the commercially available software package Isograph and a tool using Excel, which was developed in house for ESS-systems. The impact of an early reliability modeling on the design of mission critical systems will be presented as well.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI019

Export •

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

THPRI093

CSCM: EXPERIMENTAL AND SIMULATION RESULTS

3988

S. Rowan, B. Auchmann, K. Brodzinski, Z. Charifoulline, R. Denz, V. Roger, I. Romera, R. Schmidt, A.P. Siemko, J. Steckert, H. Thiesen, A.P. Verweij, G.P. Willering, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland
H. Pfeffer
Fermilab, Batavia, Illinois, USA

The copper-stabilizer continuity measurement - or CSCM - was devised to obtain a direct and complete qualification of the continuity in the 13 kA bypass circuits of the LHC, especially in the copper-stabilizer of the busbar joints and the bolted connections in the diode-leads. The circuit under test is brought to ~20 K, a voltage is applied to open the diodes, and the low-inductance circuit is powered with a pre-defined series of current profiles. The profiles are designed to successively increase the thermal load on the busbar joints up to a level that corresponds to worst-case operating conditions at nominal energy. In this way, the circuit is tested for thermal runaways in the joints - the very process that could prove catastrophic if it occurred under nominal conditions with the full circuit energy. Surveillance software and a numerical model were devised to carry out the analysis and ensure complete protection of the circuit from over-heating. A type test of the CSCM was successfully carried out in April 2013 on one main dipole and one main quadrupole circuit of the LHC. This paper describes the analysis procedure, the numerical model, and results of this first type test.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI093

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)