1. Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 1 Horizontal Tests in a Vertical Cryostat Shrikant Pattalwar STFC Daresbury Laboratory UK

2. Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 2 Outline Introduction Test Configuration Seek Comments / Suggestion

3. UK contribution €184m Total Construction cost €1.84B ESS Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 3

4. STFC ESS Delivery ~1.2m ~6m In February 2015 STFC requested to procure and test all high-β SRF elliptical cavities: Nb procurement Dressed cavity fabrication with industry Vertical tests Shipment to CEA Saclay for CM integration Testing rate of ~1 cavity/week  Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 4

5. Dressed Cavity Total of 84 dressed 704 MHz cavities: Plus 4 possible spares. Operating specification: 20 MV/m @ Q o > 5 x 10 9 Testing specification: 23.9 MV/m @ Q o > 5 x 10 9 Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 5

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7. CRYOGENICS OF EUROPEAN XFEL ACCELERATOR MODULE TEST FACILITY Bozhko Y., Petersen B., Schnautz T., Sellmann D., Wang X.L, Zhirnov A., Zolotov A., DESY Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 7 Conventional Method 1Immerse the Object (Cavity) in liquid helium bath (Vertical Cryostat) 2Pump on the Liquid helium bath with either cold compressor or Vacuum Pump to reduce the bath pressure to 30 mbar ( 2 K) 3Use 2K heat exchanger + JT valve to maintain liquid helium level Testing XFEL cavities at DESY 3 2 1

8. Vertical Cryostat for High-  Cavities Requirements work out be: Usable LHe vessel diameter ~1.5 m (Diameter of a 704 MHz cavity ~ 0.5 m) Cryostat becomes sufficiently large to test cavities horizontally LHe bath volume ~3500 l LHe required per test ~7500 l Gas handling capacity ~20 g/S (2K Hex, 2K pump, distribution Pipes, Valves, safety devices, etc. ) Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 8

9. Alternative Approach: Horizontal Tests in a Vertical Cryostat Test 3 cavities simultaneously. Each cavity already has its own helium vessel: Necessary and sufficient condition is to cool the cavity to 2K Can be easily achieved by filling liquid helium in its own vessel (with a volume of ~ only 50 l) Cryogenic Requirements: LHe per test reduces from: ~7500 l to ~1500 l (factor of 5!) Gas handling capacity reduces from: ~20 g/S to < 2 g/S (factor of 10!) Significantly simplified and lower cost ancillaries (2K Hex, 2K pump, distribution Pipes, Valves, safety devices, etc. ) Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 9

10. 10 Horizontal tests – Performance in near final configuration Automatic leak checks on helium vessel (Not possible in bath cryostat) More confidence in performance More than 75% saving on LHe Reduced test duration (quick cool- down/ warm up) Lower Operational Hazards (due to lower gas flow/less quantity of LHe) 75 % Saving on LHe and Gas Storage Risks / Issues Additional assembly steps Additional leak checks during assembly 20 g/S 2 g/S 10,000 l 2,000 l Benefits

11. Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 11 Test configurations/Pros & Cons

12. Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 12 Typical Test Scenario (excluding cavity Assembly) Test can continue for few extra days if required

13. Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 13 KEEP CLEAR Cryogenic Schematic

14. Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 14 Summary Proposal to conduct tests in horizontal configuration in a vertical cryostat Major benefits are due to substantial reduction in LHe consumption And also due to reduction in mass flow, leading to reduction in size the 2K system Mounting of Cavities on the Insert becomes more complicated but can be managed by introducing additional QC processes. So far we do not see any show stoppers or many issues We welcome any comments / suggestions/ identification of any potential issues Thank You

15. Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 15 Additional Slides

16. Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 16

17. Filename_20150922_ESS_VTF17 40K GHe from Cryoplant 4K LHe from Dewar HTR From Cryo-Plant LHe 40 K GHe To GHe Recovery JT Instrumentation for 2K Distribution TI 203 TI 205 LI 215 TI 208 TI 207 TI 206 TI204 TI 201 TI 202 TI 211 TI 210 TI 212 PI 221 PI 222 FM216 PI 223 FM217 FM218 PI 224 PI 225 PI 226 PI 227 PI 228 CV 261 CV 262 CV 263 CV 264 JT 265 CV 266 CV 267 MV 268 HT 271HT 272

18. Filename_20150922_ESS_VTF18 Instrumentation for CSI TI 107A/B V1 V2 V3 T1 T2 T3 Outside vacuum chamber Inside vacuum chamber Cooling pipes for shield cooling Dressed cavities LHe bottom fill demountable joints LHe top fill demountable joints RF probes Gas cooled radiation baffles LHe reservoir PRE-COOL (4K) 2K RTN RF Port Turbo x 3 2K SUPPLY 80K RTN 40K SUPPLY I-Port Thermal Shield WARM GHe Individual Bayonet Connections or Compound Transfer Lines TI 101A TI 101B TI 102A TI 104 TI 105 TI 103B TI 103A TI 102B TI 106 LI 111 PI 112 A/B PI 114 TI 107A/B TI 108A/B TI 109A/B TI 110A/B PI 113 A/B HT 171 HT 175 HT 174 HT 173 HT 172

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21. Filename_20150922_ESS_VTF21 1. Helium Top Fill Port Add extra CF/ISO flange as collar so that the weld-region is not disturbed. 2. Helium bottom FillCF to Flexible pipe 3. Beam Pipe VacuumCoupler Port(ISO flange via all metal angle valve) 4. RF input couplerBeam pipe side flange-2 5. RF pick upBeam pipe side flange-2 5a (OR) Pick up point 5b 6. Mounts for T-sensors? Cu mounts to bolt 4 cernox on each cavity 7. Film Heater50 W Items 3,4 and 5 factory mounted on the cavity Cavity transported in Vacuum or in N2 at what pressure? Cavity Interfaces 1 2 3 4 5a 5b Modification 6 7

22. Shrikant_Pattalwar TTC 2015 Dec 1, 2015 SLAC 22