Alignment and assembling of the cryomodule Yun He, James Sears, Matthias Liepe MLC external review October 03, 2012

10/3/2012Yun HE, MLC External Review2 Outline  Requirements and challenges  Differential thermal contractions Material properties Axial differential thermal contractions among components at cold Beamline vertical thermal contraction at cold  Dealing with differential thermal contractions Position change between vacuum vessel and coldmass Position change between HGRP and beamline Position change between 40K shield and coldmass  Assembling steps

10/3/2012Yun HE, MLC External Review3 Requirements and challenges Requirements  Allowable transverse offset (x,y): 2mm for cavities, 1.6 mm for quads Allowable pitch: 1.5 mrad (1.2 mm over the length of cavity)  Alignment is performed at room temperature  Tolerances maintained throughout thermal cycling, vacuum pumping and transport Challenges  Different material coefficients of thermal expansion among interfacing components

10/3/2012Yun HE, MLC External Review4 Differential thermal contractions Temperature dependent material properties Axial differential thermal contractions among components at cold Beamline vertical thermal contraction at cold

Table from Norihito. Ohuchi’s talk, SRF2009 Table from Carlo Pagani’s paper, SRF2005 Material properties -- coefficient of thermal expansion MaterialTemp.∆L/L G10 warp300K- 2K-0.256% SS K-2K-0.319% Al300K-40K-0.350% Ti300K-2K-0.172% Nb-Ti300K-2K-0.169% Data from NIST Used material data from NIST for calculations Most of these values are higher than TTF used

10/3/2012Yun HE, MLC External Review6 Axial differential thermal contractions among components at cold Fixed point 9.8 m, vacuum vessel at room temperature 9.5 mm -- HGRP 19 mm – thermal shield 8 mm – beamline Axial displacement due to thermal contractions of materials at cold ComponentsMaterialTemperature∆L/L∆L HGRPTi300K-2K0.172%17 mm Thermal shieldAl K-40K0.350%34.5 mm Beamline (cavity)Nb/SS300K-2K0.146%14.5 mm 7.5 mm -- HGRP 15.5 mm – thermal shield 6.5 mm – beamline Sliding post 1 mm thermal contraction – cavity LHe vessel 0.8 m

10/3/2012Yun HE, MLC External Review7 Vertical beamline displacement at cold 500 mm 140 mm ComponentsMaterialTemperature∆L/L∆L HGRP/LHe vessel Ti300K-2K0.172%0.9 mm PostG10300K-2K0.256%<0.3 mm 40K 5K Moved up by ~1.2 mm

10/3/2012Yun HE, MLC External Review8 Dealing with differential thermal contractions Position change between vacuum vessel and coldmass Position change between HGRP and beamline Position change between 40K shield and coldmass

 Longitudinal: middle post is fixed, while the side posts are slid able  Vertical: Bellows section allows displacements of beamline at cold Beamline port on end flange of warm-cold transition will be higher by 1.2 mm, so the bellows will be bent at room temperature  Coupler design allows a transverse offset up to10 mm Couplers will be offset at room temperature thus will be straight at cold 9 Brass bushing allows side post to slide on vacuum vessel top flange Replace it with roller bearings? Dealing with position change between vacuum vessel and coldmass 10/3/2012Yun HE, MLC External Review

10/3/2012Yun HE, MLC External Review10  Cavity flexible support Allows 1 mm displacement  A bellows section in chimney of cavity  Key alignment of component supports Allows beamline components to slide longitudinally relative to HGRP  Bellows in HOM absorbers HOM loads are made of stainless steal but the bellows in the HOM loads will take the difference between the length changes of the cavities and HOM loads and the HGRP  Alignment results from Injector Cryomodule WPM measurements Cavity string was aligned to 0.2 mm after cool-do wn Dealing with position change between HGRP and beamline

11 Fixed post Sliding post Left/right posts can move relative to shield in axial direction during cool-down At room temperature, side post is  offset to vac vessel port center  Concentric to shield opening At cold, side post is moved due to HGRP contraction, became  concentric to vac vessel port center  Slightly offset to shield opening center 10/3/2012Yun HE, MLC External Review Dealing with position change between shield and cold mass (posts)

10/3/2012Yun HE, MLC External Review12 Assembling steps

10/3/2012Yun HE, MLC External Review13 Assembling steps -- assemble beamline, weld 2K-2 phase line  Assemble beamline in the clean room on rail support;  Leak check and keep beamline in UHV Level components in horizontal direction (Roll) with sine-plate within ”/10”; No need to align them in other directions as bellows in HOM absorbers allow for adjustment once the beamline string is mounted to precision machined HGRP supports  Weld 2K-2 phase pipe to chimneys of cavity/magnets LHe vessels;

10/3/2012Yun HE, MLC External Review14 Assembling steps -- assemble beamline, mount to HGRP/posts  Mount beamline string onto HGRP which is supported by three posts on assembly frame;  Install tuners Connect supports Weld chimney between HGRP and 2K-2 phase pipe

10/3/2012Yun HE, MLC External Review15 Assembling steps – insert cooling lines, instrumentation wires,40K shield  Install 2K, 5K cooling pipes;  Install 40K shield upper sheets and 40K cooling pipes;  Connect jumpers to 5K, 40K intercepts;  Instrumentation wires  Install 40K shield lower sheets;  Magnetic shields;  MLI

10/3/2012Yun HE, MLC External Review16 Assembling steps – insert cold mass into vacuum vessel  Rail cold mass into vacuum vessel;  Mount alignment brackets to support post;  Jack up brackets to relieve the cold mass weight from rails;  Align post position with respect to the vacuum vessel fiducial points Rails for cold mass insertion Alignment bracket Vacuum vessel reference arm, with precision machined conical centering surface for a TH-sphere or reflector

Position of posts can be adjusted via rods/screws 1710/3/2012Yun HE, MLC External Review Assembling steps – align cold mass to vacuum vessel references Adjust positions of posts relative to vacuum vessel reference arms; Lock the position of middle post and the position of side posts in horizontal direction; Install cryogenic valves; connections of valves to pipes Support post Support bracket Reference surfaces for TH spheres

10/3/2012Yun HE, MLC External Review18 The End