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Title: Upgrade of the LHC magnet interconnections thermal shielding

Abstract

The about 1700 interconnections (ICs) between the Large Hadron Collider (LHC) superconducting magnets include thermal shielding at 50-75 K, providing continuity to the thermal shielding of the magnet cryostats to reduce the overall radiation heat loads to the 1.9 K helium bath of the magnets. The IC shield, made of aluminum, is conduction-cooled via a welded bridge to the thermal shield of the adjacent magnets which is actively cooled. TIG welding of these bridges made in the LHC tunnel at installation of the magnets induced a considerable risk of fire hazard due to the proximity of the multi-layer insulation of the magnet shields. A fire incident occurred in one of the machine sectors during machine installation, but fortunately with limited consequences thanks to prompt intervention of the operators. LHC is now undergoing a 2 years technical stop during which all magnet's ICs will have to be opened to consolidate the magnet electrical connections. The IC thermal shields will therefore have to be removed and re-installed after the work is completed. In order to eliminate the risk of fire hazard when re-welding, it has been decided to review the design of the IC shields, by replacing the welded bridges with amore » mechanical clamping which also preserves its thermal function. An additional advantage of this new solution is the ease in dismantling for maintenance, and eliminating weld-grinding operations at removal needing radioprotection measures because of material activation after long-term operation of the LHC. This paper describes the new design of the IC shields and in particular the theoretical and experimental validation of its thermal performance. Furthermore a status report of the on-going upgrade work in the LHC is given.« less

Authors:
; ; ; ; ; ; ; ; ; ;  [1];  [2];  [3];  [4];  [5]
  1. CERN European Organization for Nuclear Research, Meyrin 1211, Geneva 23, CH (Switzerland)
  2. The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul.Radzikowskiego 152, 31-324 Krakow (Poland)
  3. NTUA National Technical University of Athens, Heeron Polytechniou 9, 15780 Zografou (Greece)
  4. Wroclaw University of Technology, Faculty of Mechanical and Power Engineering, Wyb. Wyspianskiego 27, Wroclaw, 50-370 (Poland)
  5. Lancaster University, Bailrigg, Lancaster, LA1 4YW (United Kingdom)
Publication Date:
OSTI Identifier:
22263952
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1573; Journal Issue: 1; Conference: International cryogenic materials conference, Anchorage, AK (United States), 17-21 Jun 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; CERN LHC; CRYOSTATS; DESIGN; FIRE HAZARDS; HELIUM; SUPERCONDUCTING MAGNETS; THERMAL SHIELDS

Citation Formats

Musso, Andrea, Barlow, Graeme, Bastard, Alain, Charrondiere, Maryline, Deferne, Guy, Dib, Gaëlle, Duret, Max, Guinchard, Michael, Prin, Hervé, Craen, Arnaud Vande, Villiger, Gilles, Chrul, Anna, Damianoglou, Dimitrios, Strychalski, Michał, and Wright, Loren. Upgrade of the LHC magnet interconnections thermal shielding. United States: N. p., 2014. Web. doi:10.1063/1.4860735.
Musso, Andrea, Barlow, Graeme, Bastard, Alain, Charrondiere, Maryline, Deferne, Guy, Dib, Gaëlle, Duret, Max, Guinchard, Michael, Prin, Hervé, Craen, Arnaud Vande, Villiger, Gilles, Chrul, Anna, Damianoglou, Dimitrios, Strychalski, Michał, & Wright, Loren. Upgrade of the LHC magnet interconnections thermal shielding. United States. doi:10.1063/1.4860735.
Musso, Andrea, Barlow, Graeme, Bastard, Alain, Charrondiere, Maryline, Deferne, Guy, Dib, Gaëlle, Duret, Max, Guinchard, Michael, Prin, Hervé, Craen, Arnaud Vande, Villiger, Gilles, Chrul, Anna, Damianoglou, Dimitrios, Strychalski, Michał, and Wright, Loren. Wed . "Upgrade of the LHC magnet interconnections thermal shielding". United States. doi:10.1063/1.4860735.
@article{osti_22263952,
title = {Upgrade of the LHC magnet interconnections thermal shielding},
author = {Musso, Andrea and Barlow, Graeme and Bastard, Alain and Charrondiere, Maryline and Deferne, Guy and Dib, Gaëlle and Duret, Max and Guinchard, Michael and Prin, Hervé and Craen, Arnaud Vande and Villiger, Gilles and Chrul, Anna and Damianoglou, Dimitrios and Strychalski, Michał and Wright, Loren},
abstractNote = {The about 1700 interconnections (ICs) between the Large Hadron Collider (LHC) superconducting magnets include thermal shielding at 50-75 K, providing continuity to the thermal shielding of the magnet cryostats to reduce the overall radiation heat loads to the 1.9 K helium bath of the magnets. The IC shield, made of aluminum, is conduction-cooled via a welded bridge to the thermal shield of the adjacent magnets which is actively cooled. TIG welding of these bridges made in the LHC tunnel at installation of the magnets induced a considerable risk of fire hazard due to the proximity of the multi-layer insulation of the magnet shields. A fire incident occurred in one of the machine sectors during machine installation, but fortunately with limited consequences thanks to prompt intervention of the operators. LHC is now undergoing a 2 years technical stop during which all magnet's ICs will have to be opened to consolidate the magnet electrical connections. The IC thermal shields will therefore have to be removed and re-installed after the work is completed. In order to eliminate the risk of fire hazard when re-welding, it has been decided to review the design of the IC shields, by replacing the welded bridges with a mechanical clamping which also preserves its thermal function. An additional advantage of this new solution is the ease in dismantling for maintenance, and eliminating weld-grinding operations at removal needing radioprotection measures because of material activation after long-term operation of the LHC. This paper describes the new design of the IC shields and in particular the theoretical and experimental validation of its thermal performance. Furthermore a status report of the on-going upgrade work in the LHC is given.},
doi = {10.1063/1.4860735},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1573,
place = {United States},
year = {Wed Jan 29 00:00:00 EST 2014},
month = {Wed Jan 29 00:00:00 EST 2014}
}
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