1. Overview of elliptical cryomodules vacuum system Vacuum Equipment Standardization meeting 19-20 February 2014 P. Bosland – C. Darve – N. Elias

2. General layout of the elliptical cavity cryomodule

3. Cryomodule Vacuum P&ID Insulating vacuum pumping system Cavity string pumping through the gate valves ! Cleanliness of the connected components ! 4 gauges for coupler protection and cavity vacuum monitoring

4. PI70Pressure Indicator Manometer PT70Vacuum gauge Penning PT71Vacuum gauge Pirani PT72Vacuum gauge Penning PT73Vacuum gauge Pirani SV70Safety valve 1,1-1,5 bara HV70Hand valve ? HV71Hand valve HV72Hand valve HV73Hand valve HV74Hand valve ? MPG70Main Pumping group Rotary vane pump TMP70Turbo Pumping group Turbomolecular pump Instruments for insulation vacuum PT10Vacuum gauge Penning DN40CF : Balzers IKR70 PT10Vacuum gauge Penning DN40CF : Balzers IKR70 PT10Vacuum gauge Penning DN40CF : Balzers IKR70 PT10Vacuum gauge Penning DN40CF : Balzers IKR70 GV80Gate Valve DN 100: pneumatic VAT48: 48240-CE44 GV81Gate Valve DN 100: pneumatic VAT48: 48240-CE44 XXxxVacuum gauge XXxxIon pump Instruments for beam vacuum

5. Need of leak detection efficient for cryogenic pipes saturated with He gas

6. 2. Insulating vacuum characteristics (a) – should reach better, enhanced by cryopumping (<10 -6 maximum at low temperature) (b) – from ambient pressure, or <24h?, outgassing of MLI might be important factor Medium & high beta cryomodules Vacuum tank volume (m3)7,2 LHe vessel volume (m3)0,35 Insulation volume (m3)6,4 290K vacuum vessel surface (m2)30 290K space frame surface (m2)20 50K thermal shield surface (m2)50 2K surface (m2)40 50K MLI (m2)1500 2K MLI (m2)400 Pressure (mbar) (a)< 10 -5 Pump down time (h) (b)Tbd nominal pumping speed (l/s)Tbd Pumping port diameter (mm)Tbd

7. 2. Beam pipe vacuum characteristics Medium & high beta cryomodules Cavity string volume (m3)7,2 Cavity string surface (m2) (almost all surface @ 2K)40 Pressure (mbar)< 10 -9 Pump down time (h)Tbd nominal pumping speed (l/s)Tbd Pumping port diameter (mm)Tbd

8. Some requests, proposals and requirements: 1.Need of slow pumping and refilling system for the cavity vacuum. 2.Vacuum gauges on the couplers = protection of the couplers  IKR70 (used for SPL couplers) 2.Insulating vacuum pumping groups permanently installed and permanently pumping (like XFEL, SOLEIL) 3.Primary pumps outside the tunnel 4.Need of special turbo pumps designed for working under high level of radiation ? 5.No bake out of the cavity vacuum and of the insulation vacuum.

9. Needed gases: Compressed air for electro-pneumatic valve actuation Helium for leak tests Helium for cavity RF processing ? Very clean and filtered N2 (or Ar ?) for very slow refilling of the cavities Filetered N2 for insulation vacuum refilling Other gas for leak detection on helium circuit pipes (Ar ?)

10. LHC Design Report p 351

11. LHC Design Report p 353

12. Storage and shipping of the cryomodules: * Cavity vacuum: refilled or under vacuum ? * insulation vacuum: refilled (N2)