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TUPC134 |
Results from Commissioning of the Energy Extraction Facilities of the LHC Machine
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1383 |
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- K. H. Mess, G.-J. Coelingh, K. Dahlerup-Petersen
CERN, Geneva
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The risk of damage to the superconducting magnets, busbars and current leads of the LHC machine in case of a resistive transition (quench) is being minimized by adequate protection. The protection is based on early quench detection, bypassing the quenching magnets by cold diodes, energy density dilution in the quenching magnets using heaters and, eventually, energy extraction. For two hundred and twenty-six LHC circuits (600 A and 13 kA) extraction of the stored magnetic energy to external dump resistors was required. All these systems are now installed in the machine and the final hardware commissioning has been undertaken. After a short description of the topology and definitive features, layouts and parameters of these systems the paper will focus on the results from their successful commissioning and an analysis of the system performance.
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WEPD007 |
Detection and Location of Electrical Insulation Faults on the LHC Superconducting Circuits during the Hardware Commissioning
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2413 |
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- D. Bozzini, V. Chareyre, K. H. Mess, S. Russenschuck
CERN, Geneva
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As part of the electrical quality assurance program, all superconducting circuits of the LHC have to be subjected to a (high) DC voltage, up to 1.9 kV DC, for the testing of the electrical insulation. Circuits with an insulation fault have to be repaired before powering. Fault location within a ± 3 m range over the total length of 2700 m has been achieved in order to limit the number of interconnection openings. In this paper, the methods, tooling, and procedures for the detection and location of electrical faults will be presented in view of the practical experience gained in the LHC tunnel. Three cases of faults detected and localized during the hardware commissioning phases of the LHC will be discussed.
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WEPD010 |
Electronic Systems for the Protection of Superconducting Devices in the LHC
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2422 |
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- R. Denz, K. Dahlerup-Petersen, K. H. Mess
CERN, Geneva
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The Large Hadron Collider LHC incorporates an unprecedented amount of superconducting components: magnets, bus-bars, and current leads. Most of them require active protection in case of a transition from the superconducting to the resistive state, the so-called quench. The electronic systems ensuring the reliable quench detection and further protection of these devices have been developed and produced over the last years and are currently being put into operation. The paper will describe the various protection devices and hereby focus on the final test and commissioning phase of the system. First results from operation will be presented as well as an analysis of the system performance.
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WEPD018 |
Commissioning of the LHC Current Leads
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2446 |
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- A. Ballarino, S. A. March, K. H. Mess
CERN, Geneva
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The powering of the LHC superconducting magnets relies on more than 3000 leads transporting the current from/to the cryogenic environment and rated at currents ranging from 60 A to 13000 A. The design of these leads, about 1000 of which are based on high temperature superconducting material, was entirely done at CERN, where prototype assemblies were also assembled and tested, while the series production was done in external laboratory and companies on the basis of build-to-print specification. This report summarizes the results of the tests performed during the commissioning of the LHC machine, when the leads underwent the thermal and electrical cycles necessary for the powering of the LHC superconducting circuits.
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WEOAG01 |
Prospects for a Large Hadron Electron Collider (LHeC) at the LHC
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1903 |
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- M. Klein
Liverpool University, Science Faculty, Liverpool
- H. Aksakal
N. U, Nigde
- F. Bordry, H.-H. Braun, O. S. Brüning, H. Burkhardt, R. Garoby, J. M. Jowett, T. P.R. Linnecar, K. H. Mess, J. A. Osborne, L. Rinolfi, D. Schulte, R. Tomas, J. Tuckmantel, F. Zimmermann, A. de Roeck
CERN, Geneva
- S. Chattopadhyay, J. B. Dainton
Cockcroft Institute, Warrington, Cheshire
- A. K. Ciftci
Ankara University, Faculty of Sciences, Tandogan/Ankara
- A. Eide
EPFL, Lausanne
- B. J. Holzer
DESY, Hamburg
- P. Newman
Birmingham University, Birmingham
- E. Perez
CEA, Gif-sur-Yvette
- S. Sultansoy
TOBB ETU, Ankara
- A. Vivoli
LAL, Orsay
- F. J. Willeke
BNL, Upton, New York
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The LHeC collides a lepton beam with one of the intense, LHC, hadron beams. It achieves both e± interactions with quarks at the terascale, at eq masses in excess of 1 TeV, with a luminosity of about 1033 cm-2 s-1, and it also enables a sub-femtoscopic probe of hadronic matter at unprecedented chromodynamic energy density, at Bjorken-x values down to 10-6 in the deep inelastic scattering domain. The LHeC combines the LHC infrastructure with recent advances in radio-frequency, in linear acceleration and in other associated technologies, to enable two proposals for TeV ep collisions: a "ring-ring" option in which 7 TeV protons (and ions) collide with about 70 GeV electrons/positrons in a storage ring in the LHC tunnel and a "linac-ring" option based on an independent superconducting linear accelerator enabling single-pass collisions of electrons and positrons of up to about 140 GeV with an LHC hadron beam. Both options will be presented and compared. Steps are outlined for completing a Conceptual Design Review of the accelerator complex, beam delivery, luminosity, physics and implications for experiment, following declared support by ECFA and by CERN for a CDR.
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Slides
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WEPD016 |
Electrical Quality Assurance of the Superconducting Circuits during LHC Machine Assembly
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2440 |
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- S. Russenschuck, D. Bozzini, V. Chareyre, O. Desebe, K. H. Mess
CERN, Geneva
- M. Bednarek, D. P. Dworak, E. Gornicki, P. Jurkiewicz, P. J. Kapusta, A. Kotarba, J. Ludwin, S. Olek, M. Talach, M. Zieblinski
HNINP, Kraków
- M. Klisch, B. Prochal
AGH, Cracow
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Based on the LHC powering reference database, all-together 1712 superconducting circuits have been electrically wired and interconnected in the various cryogenic lines of the LHC machine. Continuity, magnet polarity, and the quality of the electrical insulation have been the main objectives of the Electrical Quality Assurance (ELQA) activities during the LHC machine assembly. Another activity aimed at ensuring the coherence between the reference database on one side, and the polarity conventions used for beam simulation and magnetic measurements. With the assembly of the LHC now completed, the paper reviews the methods and procedures established for the ELQA, as well as the employed time and resources. The qualification results will be presented with the emphasis on the detected electrical non-conformities and their possible impact on the performance of the LHC machine.
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WEPD028 |
Performance of the Superconducting Corrector Magnet Circuits during the Commissioning of the LHC
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2470 |
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- W. Venturini Delsolaro, V. Baggiolini, A. Ballarino, B. Bellesia, F. Bordry, A. Cantone, M. P. Casas Lino, C. CastilloTrello, N. Catalan-Lasheras, Z. Charifoulline, C. Charrondiere, G. D'Angelo, K. Dahlerup-Petersen, G. De Rijk, R. Denz, M. Gruwe, V. Kain, M. Karppinen, B. Khomenko, G. Kirby, S. L.N. Le Naour, A. Macpherson, A. Marqueta Barbero, K. H. Mess, M. Modena, R. Mompo, V. Montabonnet, D. Nisbet, V. Parma, M. Pojer, L. Ponce, A. Raimondo, S. Redaelli, V. Remondino, H. Reymond, A. Rijllart, R. I. Saban, S. Sanfilippo, K. M. Schirm, R. Schmidt, A. P. Siemko, M. Solfaroli Camillocci, H. Thiesen, Y. Thurel, A. Vergara-Fernández, A. P. Verweij, R. Wolf, M. Zerlauth
CERN, Geneva
- A. Castaneda, I. Romera Ramirez
CIEMAT, Madrid
- SF. Feher, R. H. Flora
Fermilab, Batavia, Illinois
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The LHC is a complex machine requiring more than 7400 superconducting corrector magnets distributed along a circumference of 26.7 km. These magnets are powered in 1380 different electrical circuits with currents ranging from 60 A up to 600 A. Among the corrector circuits the 600 A corrector magnets form the most diverse and differentiated magnet circuits. About 60000 high current connections had to be made. A minor fault in a circuit or one of the superconducting connections would have severe consequences for the accelerator operation. All magnets are wound from various types of Nb-Ti superconducting strands, and many contain resistors to by-pass the current in case of the transition to the normal conducting state in case of a quench, and hence reduce the hot spot temperature. In this paper the performance of these magnet circuits is presented, focussing on the quench current and quench behaviour of the magnets. Quench detection and the performance of the electrical interconnects will be dealt with. The results as measured on the entire circuits will be compared to the test results obtained during the reception tests of the individual magnets.
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WEPD029 |
Performance of the Main Dipole Magnet Circuits of the LHC during Commissioning
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2473 |
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- A. P. Verweij, V. Baggiolini, A. Ballarino, B. Bellesia, F. Bordry, A. Cantone, M. P. Casas Lino, A. Castaneda, C. CastilloTrello, N. Catalan-Lasheras, Z. Charifoulline, G.-J. Coelingh, G. D'Angelo, K. Dahlerup-Petersen, G. De Rijk, R. Denz, M. Gruwe, V. Kain, B. Khomenko, G. Kirby, S. L.N. Le Naour, A. Macpherson, A. Marqueta Barbero, K. H. Mess, M. Modena, R. Mompo, V. Montabonnet, D. Nisbet, V. Parma, M. Pojer, L. Ponce, A. Raimondo, S. Redaelli, H. Reymond, D. Richter, A. Rijllart, I. Romera, R. I. Saban, S. Sanfilippo, R. Schmidt, A. P. Siemko, M. Solfaroli Camillocci, H. Thiesen, Y. Thurel, W. Venturini Delsolaro, A. Vergara-Fernández, R. Wolf, M. Zerlauth
CERN, Geneva
- SF. Feher, R. H. Flora
Fermilab, Batavia, Illinois
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During hardware commissioning of the Large Hadron Collider, 8 main dipole circuits and 16 main quadrupole circuits are tested at 1.9 K and up to their nominal current. Each dipole circuit contains 154 magnets of 15 m length, and has a total stored energy of up to 1.1 GJ. Each quadrupole circuit contains 47 or 51 magnets of 5.4 m length, and has a total stored energy of up to 20 MJ. All magnets are wound from Nb-Ti superconducting Rutherford cables, and contain heaters to quickly force the transition to the normal conducting state in case of a quench, and hence reduce the hot spot temperature. In this paper the performance of these circuits is presented, focusing on the quench current and quench behaviour of the magnets. Quench detection, heater performance, operation of the cold bypass diodes, cryogenic recovery time, electrical joints, and possible magnet-to-magnet quench propagation will be dealt with. The results as measured on the entire circuits will be compared to the test results obtained during the reception tests of the individual magnets.
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WEPP052 |
A Storage Ring Based Option for the LHeC
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2638 |
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- F. J. Willeke
BNL, Upton, New York
- F. Bordry, H.-H. Braun, O. S. Brüning, H. Burkhardt, J. M. Jowett, T. P.R. Linnecar, K. H. Mess, S. Myers, J. A. Osborne, F. Zimmermann
CERN, Geneva
- S. Chattopadhyay
Cockcroft Institute, Warrington, Cheshire
- J. B. Dainton, M. Klein
Liverpool University, Science Faculty, Liverpool
- B. J. Holzer
DESY, Hamburg
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The LHeC aims at the generation of Hadron-Lepton collisions with center of mass energies in the TeV scale and luminosities of the order of 1033 cm-2 sec-1 by taking advantage of the existing LHC 7 TeV proton ring and adding a high energy electron accelerator. This paper presents technical considerations and potential parameter choices for such a machine and outlines some of the challenges arising when an electron storage ring based option, constructed within the existing infrastructure of the LHC, is chosen.
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WEPP154 |
Linac-LHC ep Collider Options
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2847 |
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- F. Zimmermann, F. Bordry, H.-H. Braun, O. S. Brüning, H. Burkhardt, R. Garoby, T. P.R. Linnecar, K. H. Mess, J. A. Osborne, L. Rinolfi, D. Schulte, R. Tomas, J. Tuckmantel, A. de Roeck
CERN, Geneva
- H. Aksakal
N. U, Nigde
- S. Chattopadhyay
Cockcroft Institute, Warrington, Cheshire
- A. K. Ciftci
Ankara University, Faculty of Sciences, Tandogan/Ankara
- J. B. Dainton
Liverpool University, Science Faculty, Liverpool
- A. Eide
EPFL, Lausanne
- B. J. Holzer
DESY, Hamburg
- M. Klein
University of Liverpool, Liverpool
- S. Sultansoy
TOBB ETU, Ankara
- A. Vivoli
LAL, Orsay
- F. J. Willeke
BNL, Upton, New York
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We describe various parameter scenarios for a ring-linac ep collider based on LHC and an independent s.c. electron linac. Luminosities of order 1032/cm2/s can be achieved with a standard ILC-like linac, operated either in pulsed or cw mode, with acceptable beam power. Reaching much higher luminosities, up to 1034/cm2/s and beyond, would require the use of two linacs and the implementation of energy recovery. Advantages and challenges of a ring-linac ep collider vis-a-vis an alternative ring-ring collider are discussed.
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