SNS PPU Cryomodule Thermal Shield SNS PPU CRYOMODULE PDR SNS PPU CRYOMODULE PDR SNS PPU Cryomodule Thermal Shield Matt Marchlik Matt Marchlik Wednesday, February 27 2019 Wednesday, February 27 2019

Fabrication/Procurement methodology Remaining Tasks Summary Outline Requirements Design Assembly Component/function Fabrication/Procurement methodology Remaining Tasks Summary

Requirements Provide 50 K thermal radiation shielding to the cold mass Allow for thermal contraction from 300 – 50 K Handle the shipping design loads (4 vertical, 5 longitudinal, 1.5 transverse) The shipping design loads and geometry mass has not significantly changed from the original design. The design is assumed to be adequate based on past performance

Design – Assembly Overview Supply End Shield Extension Shield segments Axial nitronic rod patch panels Tuner access Panels Helium line Shield to space frame supports Field probe cable Heat intercept blocks Return End Shield Extension All shield segments and patch panels are made from (C11000 ETP Cu)

Design – Nitronic Rod Clearance Axial rod clearance slots have been widened by ~.64” per recommendation of assembly personnel Transverse rod clearance Clearance for thermal contraction verified

Design – Tuner Access Panels (other hidden) Panel support bracket

Design – Shield/Space Frame Support Shield support bands (G11) Corner support clamps (304 SS) Shield Spacer (G11)

Design – Field probe cable intercept block Original intercept block Updated intercept block The bottom block bolts onto the shield body. No back access is needed to clamp/unclamp the cable. The original block had three cable grooves Field probe cable heat intercept block was reduced in size and complexity

Design – Nitronic Rod Intercepts Each transverse nitronic rod is heat intercepted inside of the thermal shield Axial rods are not intercepted in the original design It is assumed that previous calculations showed that the heat leak through the much longer rods is negligible The original strap was made from solid copper sheet. An equivalent capacity braided copper strap was selected to replace the solid one TIG braze

Design – Helium Line 7/8 in OD, .045 in wall copper tubing runs along the length of the shield Tubing is segmented into 4 pieces by bellows assemblies The tubing segments are torch brazed to the shield segment’s strain relief cut outs Verified the wall thickness is acceptable per ASME B31.3 Verified that the SS to Cu adapter is acceptable per ASME B16.22

Design – Helium Line Brazed Shield Subassembly Bellows lock rods prevent over stretch SS to SS weld TIG braze SS to Cu socket braze Bellows assemblies integrated between each shield segment Tube brazed to the strain relief fingers of the shield segments

Design – Shield Extensions Each end of the shield is capped by an extension assembly Allow for end can connections to be made Supports will vary from the standard flat straps shown here. Currently being designed

Design – Thermal Contraction The shield assembly mounts “rigidly”(some flexibility in G11 supports) to the spaceframe. 300 – 50 K thermal contraction is ~.8 in Hardware will be omitted at two seams of the assembly to allow each segment to contract individually. Done procedurally during assembly. Some thermal contraction relief provided by twist in the 3/16” thick G11 bands

Procurement The entire assembly, including extensions, will be procured as a complete assembly. The SOW will be the primary fabrication control document. Drawings will direct fabricators to SOW Fabrication plan/traveler Materials Welding The shield circuit welds will be considered “code welds”. WPS PQR Dimensional verification Vendor site visits/witnessing Shipping

Finalize and review any new drawings Start extension drawings Remaining Design Minor changes to shield extensions Shield extension supports Drawings Finalize and review any new drawings Start extension drawings Procurement SOW PR  PO

Summary Preliminary thermal shield design is in good shape Interfaces with other subsystems have been verified Currently being considered as extensions are developed Existing drawings have been reviewed Extensions still under development Majority(~90%) of drawings for design changes have been started Extension drawings still to be created A couple of minor patch panel drawings to be created Procurement path understood

Backup Shield cooling line code calcs

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