文档介绍：ryogenic refrigerationrefrigeration forfor thethe LHCLHC
Philippe Lebrun
CERN, Geneva, Switzerland
MaTeFu Spring Training School
Cadarache, 5-9 April 2009
The largest scientific instrument in the world …
…based on advanced technology
23 km of high -field superconducting s
operating in superfluid helium at K
SuperconductorsSuperconductors forfor highhigh --fieldfield s
3000
NbTi @ K
2500 NbTi @ K
Nb3Sn @ K
LHC Spec Cable 1
2000
LHC Spec Cable 2
1500 + 3 tesla
Jc [A/mm2] Jc 1000
500
0
6 7 8 9 10 11 12
B [T]
ryogenic systemsystem layoutlayout
• 5 cryogenic islands
• 8 cryogenic plants, each serving adjacent sector, interconnected when possible
• Cryogenic distribution line feeding each sector
Configuration of cryogenics at LHC even point
Odd point Even point Odd point
MP Storage MP Storage MP Storage
K New Existing K
Refrigeration K K Refrigeration
Unit Refrigerator Refrigerator Unit
Warm Warm Warm Warm
pressor
Station Station Station Station
Cold Box Upper
Cold Box
ShaftShaftShaft Surface Surface Surface
Lower
Cold Box
Cold Cold
pressor Cavern Cavern Cavern
box InterconnectionInterconnection Box Box box
DistributionDistribution Line Line DistributionDistribution Line Line
Cryostats, DFB, ACS Cryostats, DFB, ACS Tunnel Tunnel Tunnel
LHC Sector ( km) LHC Sector ( km)
ryogenic plantsplants
K refrigerators K refrigeration units
(18 kW @ K) ( kW @ K)
ryogenic storagestorage andand distributiondistribution
Vertical transfer line Vertical
GHe storage LIN storage
Cryo- string Distribution line Interconnection box
AnalysisAnalysis && managementmanagement ofof heatheat loadsloads
Analysis Management
• Heat inleaks
– Radiation 70 K shield, MLI
– Residual gas conduction Vacuum < 10 -4 Pa
– Solid conduction Non-metallic supports
Heat intercepts
• Joule heating
– Superconductor splices Resistance < a few nΩ
• Beam-in