Coldex recommissioning and experimental program

2. G.Vandoni Coldexrecommissioning and experimental program on behalf of V.Baglin, G.Bregliozzi, P.Chiggiato, B.Jenninger, M.Taborelli, H.Neupert, K.Brodzinski, M.Pezzetti, V.Inglese G.Vandoni at IEFC

3. Outline • Coldex presented • Cryogenics for Coldex and Crab Cavity: a parallel view • Schedule: • recommissioning • operating • Removing • Conclusions G.Vandoni at IEFC

4. What is Coldex Cold (Bore) Ex(periment) LHC cold bore and beam screen section, for e-cloud studies Presently in SPS LSS4, exploiting the cryogenic infrastructure in BA4. BIBLIOGRAPHY Vacuum 73 (2004) 201–206 LHC Project Report 721 (2004) LHC Project Report 584 (2002) LHC Project Report 435 (2000) … displacement tables G.Vandoni at IEFC

5. Coldex history 1994 Designed as mock-up for a LHC cold vacuum chamber. Constructed at NIKHEF 1997 Delivered to CERN after acceptance tests. 1999 Installed in EPA, in synchrotron radiation beam… 2001 …then in positron and electron beams 2001 Installed in b.113 for cryo-sorber studies with gas injection. 2002 Installed in SPS, in field free region LSS4, to measure pressure, gas composition, heat load induced by e-cloud in LHC type beams. Preceded by the WAMPAC calorimeter. Exploits the cryogenic infrastructure for SPS 400MHz cavities. 2003 Change of elliptical beam screen for circular one G.Vandoni at IEFC

6. What does Coldex measure Thermal Vacuum Particles Heat load on cold bore and beam screen Total pressure Partial pressure (gas composition) Electron flux VERSUS: Beam parameters: bunch structure (train, spacing) and density (intensity scan) Beam screen conditioning (history, scrubbing, gas injection) and coating (SEY), physisorbed gas Beam screen temperature Parameters measured also on WAMPAC calorimeter: → distinction between warm and cold G.Vandoni at IEFC

7. Why is this important for the LHC • HL-LHCCarbon coated beam screen for inner triplets • Mitigation of e-cloud • Background reduction to the experiments Validation of carbon coated beam screen in Coldex • Experimental program focus:carbon coated BS • e-cloud threshold in carbon coated BS versus BS temperature 5K – 20K for: • Bunch structure (train, batches, spacing…) • Intensity scan • Heat load on carbon coated beam screen • Gas composition evolution during long term beam exposure (~ 1 week) • Electron stimulated desorption yield • Operation aspects: reconditioning time after venting, long term gas • condensation,cryogenic loops control G.Vandoni at IEFC

8. Coldex & Crab Cavity: cryogenics Cold box DISTRIBUTION SYSTEM Transfer lines Buffering and phase separation He return to refrigerator He recovery to storage He recuperation Client G.Vandoni at IEFC

9. Coldex & Crab Cavity: cryogenics Cold box DISTRIBUTION SYSTEM Broad dynamic range: 2W-18W Existing system, but not operated since 2004 Refrigeration capacity larger than max heat load || Revision (integrity, tightness, instrumentation) and recommissioning He recuperation COLDEX G.Vandoni at IEFC

10. Coldex & Crab Cavity: cryogenics Cold box DISTRIBUTION SYSTEM Refrigeration capacity close to estimated heat load || New system must be designed: Rigid transfer lines over most length Pre-cooling He recuperation CRAB CAVITY G.Vandoni at IEFC

11. Re-commissioning Coldex CRYOGENICS (TE/CRG) Cold box revision Coldex cryogenic distribution recommissioning Cryogenic instrumentation revision Cryogenic electricity & controls overhaul Revision of recovery line needed for Crab Cavity VACUUM (TE/VSC) Revision of vacuum hardware Overhaul of Vacuum and Displacement Table controls Removal, coating and installation of carbon coated Beam Screen Coldex in SPS interlock chain Preparation of Coldex removal for Crab Cavity tests: Production of parking and transport tool G.Vandoni at IEFC

12. Coldex & Crab Cavity: LS1 G.Vandoni at IEFC

13. Coldex SPS run BEAM COLDEX Access BA4 (20’) Coldexcooldown 4-5 dd Gas precondensation preparation 1 week Access BA4 (30’) 2dd to 1 week Coldex IN MD Stable, defined beam through Coldex Coldex OUT Access BA4 (30’) 1 week Coldexwarmup G.Vandoni at IEFC

14. Coldex experimental program Sep 2014 SPS startup 1 x Long term study Beam conditions: scrubbing run Scan in T SPS operation 4 to 5 x Dedicated MDs 2dd beam, each, preceded and followed by 30min access Cooldown/Warmup, in shadow of SPS operation 1 x Long term study (depending on result of 1st one) • Coldex IN: aperture limitation • Incompatible with LHC filling • Compatible with high intensity beams (fixed targets)? Nov 2015 G.Vandoni at IEFC

15. Coldex staged removal – Dec 2015 1 day 2.5 days 0.5 day • UncableColdex • Disconnect and remove cryogenic service • Remove Y chambers • Remove forward chamber • Bring Coldex forward • Charge Coldex and install on transportation tool • Park (BA5 pit?) • Remove Coldex from BA4 • Remove translation tables CRAB CAVITY cryomodule By-pass chambers Keep door open to reinstallation after crab cavity tests G.Vandoni at IEFC

16. Conclusions • Coldex: a versatile test bench for cryogenic and vacuum tests for LHC • Coldex validation of carbon coated beam screen is essential for HI-LUMI inner triplets upgrade • Specification of Crab cavity and Coldex cryogenic distribution schemes are dissimilar: parallel revision of Coldex system and development of new Crab Cavity system are the proposed baseline • Schedule for recommissioning, MDs and removal end 2015 G.Vandoni at IEFC

18. Close SPS Cold check-out and beam set-up G.Vandoni at IEFC

19. Coldex vacuum scheme TETM G.Vandoni at IEFC

20. Coldex cryogenics scheme TETM G.Vandoni at IEFC

21. LHC Beam screen 17cm Isolated segment for current measurement G.Vandoni at IEFC

22. Why not install Coldex in LHC? No cryogenic infrastructure in the LHC Impedance adapted to SPS The LHC is not a test bench G.Vandoni at IEFC