1 LUND March 16 th, 2016 ESS ELLIPTICAL CRYOMODULE Vacuum vessel: Ports and sealing, Manufacturing feedback LUND, March 16th, 2016 Unité mixte de recherche CNRS-IN2P3 Université Paris-Sud Orsay cedex Tél. : Fax : LUND March 16 th, 2016

2 INSULATION VACUUM SEALS M-ECCTD STATUS Bell flange Elastomer Coupler flange Helicoflex He valve (x2) Elastomer Pumping port (x2?) Elastomer Jumper Elastomer Trap doors (x8) Elastomer Rupture disk pipe (x2) Elastomer Jacks(x12) Elastomer Windows (x4) CF63 Copper Central flat cover (x2) Helicoflex Tip flat cover (x2) Elastomer Safety valve Elastomer Feedthrough ports (x6) & connectors (x12) Elastomer instrumentation(x2) Elastomer Coupler He outlet (x4) Elastomer Jumper connection Elastomer Elastomeric O Ring everywhere, except: -Windows (x4), CF63 copper -Extremity central flat cover (x2), Metallic Helicoflex -Coupler flange (x4), Metallic Helicoflex

3 LUND March 16 th, 2016 INSULATION VACUUM SEALS PROPOSALS FOR H-ECCTD & SERIES PRINCIPLES -No permanent elastomeric seal due to radiations rate and normal ageing -Elastomeric O Ring seals for gaskets that can be replaced easily during maintenance operations (no opening of extremity covers, therefore removing of the cryomodule) -Aluminium for other gaskets with standard dimensions -Special metallic references (Helicoflex or similar) for non standard dimensions Aluminium gaskets

4 LUND March 16 th, 2016 INSULATION VACUUM SEALS PROPOSALS FOR H-ECCTD & SERIES Jumper connection ?? Elastomer: seals can be changed easily without removing the cryomodule from the beam line (maintenance operation) Aluminium: standard diameter Helicoflex: non standard or too big diameter

5 LUND March 16 th, 2016 VACUUM VESSEL UPDATE PROPOSALS FOR H-ECCTD & SERIES Coupler bells Turned to Helicoflex gasket Helium valve(x2) Turned to alu. gasket From 2 DN100 pumping ports to a DN160 single ? Located on the top of the vacuum vessel ( ESS design) Jumper Turned to Helicoflex gasket Pipes for rupture disks (x2) Turned to aluminium gasket Supports drilling to finalize Extremity cover (x2) Turned to Helicoflex gasket? Flange for rupture disk (x2) to rework by final machining -Other nozzles with aluminium gaskets? 1 DN160 nozzle removed for series (not for H-ECCTD)

6 LUND March 16 th, 2016 VACUUM VESSEL MANUFACTURING FEEDBACK -No major problems during fabrication. -Nozzle holes realized by machining: good position accuracy for the different ports after welding. -Acceptance report accurate after final machining, except for the jumper flange that is 3mm too low. -Some non-conformities to correct during factory acceptance, such as jacks holes not threaded in particular. -Global helium leak rate of 3x10 -8 mbar.l/s instead of mbar.l/s (too harsh, to be lowered) due to gaskets impregnation. Weld seams and nozzles checked one by one. OK. The vacuum vessel has not to be considered as a critical part, but need good manufacturing practices and a constant fabrication follow-up