1. Overview of Main Linac Cryomodule (MLC)
Yun HE
On behalf of
Matthias Liepe, Eric Smith, James Sears, Dan Sabol, Joe Conway, Peter Quigley, Tim O’Connell, Ralf Eichhorn, Georg Hoffstaetter
10/3/2012
Yun HE, MLC External Review

2. Yun HE, MLC External Review
Linac cryomodule
0.25 m Cold-warm transition
Reduces cost and Linac length
Requires entire warm-up for repairing
Linac A
344 m with 35 cryomodules
Total 64 cryomodules
Each cryomodule unit
9.8 m long
six packages of 7-cell cavity/Coupler/tuner
a SC magnets/BPMs package
five regular HOM absorbers/two taper HOM absorbers
Cryomodule units are connected with no intervening warm breaks, and share a common insulation vacuum
Linac B
285 m with 29 cryomodules
SC magnets & BPMs
7-cell cavity
Beamline HOM absorber
Intermodule unit
nominal length: 9.8 m
10/3/2012
Yun HE, MLC External Review

3. Yun HE, MLC External Review
Cryomodule unit
Cryogenic valves
Beamline string supported by HGRP via three posts
Beam
Pneumatic gate valve
Manual gate valve
Cavity package
All ports are on aisle side in the tunnel
Coupler downstream of cavity
SC magnets downstream of cavities
10/3/2012
Yun HE, MLC External Review

4. Module interconnection Cryo-feed entry module
Slide intermodule unit
Cryogen transfer pipes welded in situ
Beamline interconnection unit connects two modules
All cryo pipes inside module
HGRP
40-80 K 5K 2K
Cryo-feed entry module, inserted between two modules
Cryogens transferred via vertical shafts to near one end of each linac
A vacuum break separates refrigerator and cryomodule vacuum
10/3/2012
Yun HE, MLC External Review

5. Cross-sectional view of module
HGRP support post + alignment
Rails
40K shield
+ Mu-metal shield
Cryogenic valves
HGRP 4”
2K-2 Phase
9.5”
Input coupler
Vacuum vessel
Φ0.965 m OD
Cavity in 2K Helium bath
10/3/2012
Yun HE, MLC External Review

6. Yun HE, MLC External Review
Cryogenic piping
6 lines of Φ50 mm pipes
6K return
bar
2K supply
subcooled bar
pre-cool gas for cool-down
80K return
bar
40K supply
bar
HGRP
1.8K gas
40K delivery
bar
2K-2 Phase
1/3 full level
4.5K supply
bar 2K
10/3/2012
Yun HE, MLC External Review

7. Cryogenic flow control
Each cryomodule has local manifolds, with the flow adjusted by four valves
JT valve – from 2K supply to 2K-2 phase
Pre-cool valve – from 2K supply to pre-cool
5K line valve – from 4.5K supply to local distribution
40K line valve – from 40K supply to local distribution
5K local distribute
JT valve
40K local distribute
Pre-cool 5K
40K
Pre-cool
Local distribute
2K-2 Phase
10/3/2012
Yun HE, MLC External Review

8. Cryogen distribution in each cryomodule
¼” SS tubes provide helium flow to HOM absorbers and couplers at 5K, K thermal intercepts
a separate line for each cavity or magnets package
10/3/2012
Yun HE, MLC External Review

9. Yun HE, MLC External Review
Prototype cryomodule
Differences of Prototype Module from Linac Module
Prototype module
Linac module
SC magnets/BPMs No
Yes
Wire position monitor
Cryogenic feeding
Front
cryo-feed cap
Side
cryo-feed module
Beamline warm-cold transition
Connection between HGRP & 2 phase
Middle & end
Middle
Cryogenic piping
With flange/elbow
pre-welded
Straight
Welded in-situ
Intermodule unit
Replaced by end cap
Cryo-feed cap
End cap
Flange-to-flange length: 10.4 m
10/3/2012
Yun HE, MLC External Review