Alignment and assembling of the cryomodule Yun He

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

Outline Ø Requirements and challenges Ø Differential thermal contractions • • • Material properties Axial differential thermal contractions among components at cold Beamline vertical thermal contraction at cold ØDealing with differential thermal contractions • • • Position change between vacuum vessel and coldmass Position change between HGRP and beamline Position change between 40 K shield and coldmass ØAssembling steps 10/3/2012 Yun HE, MLC External Review 2

Requirements and challenges Requirements Ø Allowable transverse offset (x, y): 2 mm for cavities, 1. 6 mm for quads Allowable pitch: 1. 5 mrad (1. 2 mm over the length of cavity) Ø Alignment is performed at room temperature Ø Tolerances maintained throughout thermal cycling, vacuum pumping and transport Challenges Ø Different material coefficients of thermal expansion among interfacing components 10/3/2012 Yun HE, MLC External Review 3

Differential thermal contractions • Temperature dependent material properties • Axial differential thermal contractions among components at cold • Beamline vertical thermal contraction at cold 10/3/2012 Yun HE, MLC External Review 4

Material properties -- coefficient of thermal expansion Used material data from NIST for calculations Data from NIST Material Temp. ∆L/L G 10 warp 300 K- 2 K -0. 256% SS 316 300 K-2 K -0. 319% Al 300 K-40 K -0. 350% Ti 300 K-2 K -0. 172% Nb-Ti 300 K-2 K -0. 169% Most of these values are higher than TTF used Table from Norihito. Ohuchi’s talk, SRF 2009 Table from Carlo Pagani’s paper, SRF 2005

Axial differential thermal contractions among components at cold Axial displacement due to thermal contractions of materials at cold Components Material Temperature ∆L/L ∆L HGRP Ti 300 K-2 K 0. 172% 17 mm Thermal shield Al 1100 300 K-40 K 0. 350% 34. 5 mm Beamline (cavity) Nb/SS 300 K-2 K 0. 146% 14. 5 mm Sliding post Fixed point Sliding post 9. 8 m, vacuum vessel at room temperature 7. 5 mm -- HGRP 15. 5 mm – thermal shield 9. 5 mm -- HGRP 0. 8 m 19 mm – thermal shield 8 mm – beamline 6. 5 mm – beamline 1 mm thermal contraction – cavity LHe vessel 10/3/2012 Yun HE, MLC External Review 6

40 K Components Material Temperature ∆L/L ∆L HGRP/LHe vessel Ti 300 K-2 K 0. 172% 0. 9 mm Post G 10 300 K-2 K 0. 256% <0. 3 mm 500 mm 5 K 140 mm Vertical beamline displacement at cold Moved up by ~1. 2 mm 10/3/2012 Yun HE, MLC External Review 7

Dealing with differential thermal contractions • Position change between vacuum vessel and coldmass • Position change between HGRP and beamline • Position change between 40 K shield and coldmass 10/3/2012 Yun HE, MLC External Review 8

Dealing with position change between vacuum vessel and coldmass Ø Longitudinal: middle post is fixed, while the side posts are slid able • • Brass bushing allows side post to slide on vacuum vessel top flange Replace it with roller bearings? Ø 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 Ø Coupler design allows a transverse offset up to 10 mm • Couplers will be offset at room temperature thus will be straight at cold 10/3/2012 Yun HE, MLC External Review 9

Dealing with position change between HGRP and beamline Ø Cavity flexible support • Allows 1 mm displacement Ø A bellows section in chimney of cavity Ø Key alignment of component supports • Allows beamline components to slide longitudinally relative to HGRP Ø 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 Ø Alignment results from Injector Cryomodule WPM measurements • Cavity string was aligned to 0. 2 mm after cool-down 10/3/2012 Yun HE, MLC External Review 10

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

Assembling steps 10/3/2012 Yun HE, MLC External Review 12

Assembling steps -- assemble beamline , weld 2 K-2 phase line Ø Assemble beamline in the clean room on rail support; Ø Leak check and keep beamline in UHV • • Level components in horizontal direction (Roll) with sine-plate within 0. 0005”/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 Ø Weld 2 K-2 phase pipe to chimneys of cavity/magnets LHe vessels; 10/3/2012 Yun HE, MLC External Review 13

Assembling steps -- assemble beamline , mount to HGRP/posts Ø Mount beamline string onto HGRP which is supported by three posts on assembly frame; Ø Install tuners Weld chimney between HGRP and 2 K-2 phase pipe Connect supports 10/3/2012 Yun HE, MLC External Review 14

Assembling steps – insert cooling lines, instrumentation wires, 40 K shield Ø Ø Ø Ø Install 2 K, 5 K cooling pipes; Install 40 K shield upper sheets and 40 K cooling pipes; Connect jumpers to 5 K, 40 K intercepts; Instrumentation wires Install 40 K shield lower sheets; Magnetic shields; MLI 10/3/2012 Yun HE, MLC External Review 15

Assembling steps – insert cold mass into vacuum vessel Ø Ø 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 10/3/2012 Yun HE, MLC External Review 16

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 Position of posts can be adjusted via rods/screws Reference surfaces for TH spheres Support bracket Support post 10/3/2012 Yun HE, MLC External Review 17

The End 10/3/2012 Yun HE, MLC External Review 18