The HiLumi LHC Design Study (a sub-system of HL-LHC) is co-funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
Cooling Update(27 March 2014)
Rob van Weelderen, Cryogenic Group, Technology Department, CERN
Overview• Fluka Heat Loads + Explicit Design Margins• 1.9 K Heat load limits for IT with – double HX in
Q1 to Q3 + intermediate pumping• 1.9 K Heat load limits for D1 – CP with –single
HX and with/without intermediate pumping• Beamscreen cooling
Placing of cryo-equipment considered (variant 4)
Q1,Q2a,Q2b,Q3: actively cooled for about 41 m, double-HXs neededCP,D1 : actively cooled for about 16 m, single-HXs desired
• Phase-separator &• Piping entries/exits
• Phase-separator &• Piping entries/exits• QRL-jumper
• SM &• QRL-jumper• Phase-
separator• Piping
entries/exits
20 30 40 50 60 70 80distance to IP (m)
Q1 Q3Q2a Q2bM
CB
X
MC
BX
MC
BX
CP D1
Q: 140 T/mMCBX: 2.1 T 2.5/4.5 T mD1: 5.6 T 35 T m
Additional low pressure pumping
D1 & IT: Fluka heat loads
Courtesy L. S. ESPOSITO
However these values have to be augmented due to additional loads
D1 & IT: Fluka + additional heat loads
beam-screen contact load 0.5W/mstatic heat load 0.5W/mcryostat ends 16Welectron cloud 150Wimage currents ?W
Q1-Q2A ~ 247 W,Q2B-Q1B ~ 322 W,D1+CP ~ 202 W,Beam screens ~ 633 W
Image currents 0.5 W/m on BS (tbc)
What will be our design choice?
Propose + 20 % margin:~ 925 W at 1.9 K,~ 759 W at BS
Heat Loads (W) 50 cm gap in ICs 50 cm gap in ICs3Magnet cold mass Beam screen
Q1A + Q1B 110 150Q2A + orbit corr. 105 50Q2B + orbit corr. 130 70Q3A + Q3B 160 60CP 70 45D1 (160 mm) 100 50Interconnects 25 85beam-screen contact load 27 -27static heat load 27 0cryostat ends 16 0electron cloud 0 150image currents 0 ?Total 771 633
Minimal need(569 W)
Practical T-regulation limit,(800 W)
Hard limit,HX overflowing(1000 W)
D1 + CP (~14.9 m long) needed 202 W without contingency
1) Using a full length double HX: 250 W at 2x49 mm ID, 2x58 mm Yoke-holes2) Using a full length single HX : 125 W at 1x49 mm ID, 1x58 mm Yoke-hole Not enough!
- Limited by vapour velocity (green is ok)- No good regulation possible/HX-area (red, forbidden)
- Intermediate pumping between CP and D1 and with single HX, limited by HX-area
"Power (W), 6m 1HX" "single 6m long HX ID (mm)"40 3545 4050 4555 5060 5565 6070 6575 70
"Power (W)" "Double HX ID (mm)" "single HX ID (mm)"50 24 32100 32 44150 38 53200 44 61250 49300 53350 57400 61
