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

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

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

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

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

Yun HE, MLC External Review Cryogenic piping 6 lines of Φ50 mm pipes 6K return Gas @3 bar 2K supply subcooled liquid @1.2 bar pre-cool gas for cool-down 80K return Gas @18 bar 40K supply Gas @20 bar HGRP 1.8K gas 40K delivery Gas @20 bar 2K-2 Phase 1/3 full level 4.5K supply Fluid @3 bar 2K 10/3/2012 Yun HE, MLC External Review

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

Cryogen distribution in each cryomodule ¼” SS tubes provide helium flow to HOM absorbers and couplers at 5K, 40-80 K thermal intercepts a separate line for each cavity or magnets package 10/3/2012 Yun HE, MLC External Review

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