1. Cryogenics for crab cavities – SPS/LHC 2 nd HiLumi LHC meeting – Frascati (Italy) 15 November 2012 K. Brodzinski and L. Tavian on behalf of cryogenic team at CERN K. Brodzinski - HiLumi LHC, Frascati 20121

2. Contents 2 Baseline for the cavities testing – general assumptions SPS BA4 cryogenic infrastructure Existing cryogenics and required modifications Budget and planning LHC cryogenics at P4 and at Hi Lumi experiments (P1 & 5) Conclusions

3. Baseline for the tests Crab Cavity test will be performed at 2 K firstly at SPS ring then integrated on LHC. (LHC is not considered as a test bench … -> that is why SPS test is required) P4 - Test on SPS then LHC P4 ?- Planned final destination on LHC K. Brodzinski - HiLumi LHC, Frascati 20123

4. Sulzer-Linde TCF20 in BA4 Nicolas Delruelle K. Brodzinski - HiLumi LHC, Frascati 20124 At SPS BA4 there is a 4.5 K cryogenic infrastructure used last time about 8 years ago for COLDEX experiment. It is foreseen to test its capacity and upgrade it for 2 K refrigeration – refurbishment is underway

5. TCF20 – and required upgrade Existing 4.5 K cryogenics Coupler heat intercept Subcooling HX VLP heater (~2 kW) He guard Warm pumping unit (1 g/s @ 15 mbar  1500 m 3 /h) JT valve VLP line 5 Cryolines Thermal shield Pressure relief valves Warm recovery line Required 2 K cryogenics All parts marked in red have to be developed, integrated, installed and commissioned. Service module Crab cavity cryostat COLDEX K. Brodzinski - HiLumi LHC, Frascati 2012

6. Crab-cavity test in SPS Additional specific 2 K equipments Warm pumping unit to be integrated in BA4 ! (new or recovered from AMS – needs service) Subcooling heat exchanger and JT valve to be integrated in dedicated service module. K. Brodzinski - HiLumi LHC, Frascati 20126

7. Crab-cavity test in SPS – limitations K. Brodzinski - HiLumi LHC, Frascati 20127 Crab cavity cooling at 2 K  TCF20 cryoplant used in pure liquefaction TCF20 means 20 l/h = 0.7 g/s of LHe Estimated thermal loads: Coupler heat intercepts: 2 W => ~0.1 g/s of liquefaction Dynamic RF load at 2 K: ~12 W => ~0.57 g/s of liquefaction Static heat inleaks (service module, cryostat, transfer lines): ? TCF20 T-S Diagram Guaranteed capacity: 87.5 W @ 4.5 K (i.e. isentropic equivalent to ~0.85 g/s of liquefaction)

8. Measured TCF20 refrigeration capacity 120 W available in refrigeration mode ! (+ 35 %) Giorgio Passardi K. Brodzinski - HiLumi LHC, Frascati 20128

9. Crab-cavity test in SPS TCF20 capacity limitation Conclusions: Liquefaction capacity measurement mandatory to confirm possibility of cooling @ 2 K Only one cavity can be tested with existing cryo plant (above loads are given for one cavity) Realistic specification needed ! Dynamic heat load old ass. (12 W) new ass. (2.5 W) (5 W per module) Coupler intercepts (2 W) (2 W) (4 W per module) Static heat load (4 W ?) (4 W ?) (5 W per SM + cryostat) Could be a difficult limit 0.70.85 1.2 Liquefaction capacity line [g/s] K. Brodzinski - HiLumi LHC, Frascati 20129

10. Crab-cavity test in SPS Additional specific 2 K equipment Refurbishment of existing equipment (4.5 K) 150 kCHF Sub cooling heat exchanger 12 kCHF Warm pumping unit (WPU)100 kCHF He guard for pressure relief valves 10 kCHF VLP heater 20 kCHF JT expansion valve4 kCHF Service Module + piping 50 kCHF Total ~350 kCHF Remarks: 1. some additional cost for cryostat design can occurred e.g. beam screen circuit 2. if WPU cannot be installed underground, a new VLP line must be integrated in the BA4 shaft (DN100 – 20 kCHF) 3. No specific purifier foreseen for impurity management of the VLP circuit, i.e. availability affected in case of 2 K refrigeration. K. Brodzinski - HiLumi LHC, Frascati 201210

11. Tentative SPS CC cryogenic schedule K. Brodzinski - HiLumi LHC, Frascati 201211 Surface equipment (GHe storage, compressor station and oil separation system) – refurbishment completed (run test to be done by end of 2012) Cold box refurbishment is underway – run test on the beginning of LS1 Installation of liquefaction test instrumentation and test performance – by 15 June 2013 (cut of cooling water in SPS BA4 until ~ 15 September 2013). Development, installation and commissioning of 2 K equipment by end of LS1 Remark: Integration of 2 K cryo equipment in the tunnel looks tight – if not possible  heavy complications – possibility of mentioned transfer line construction in the shaft to the surface = more logistics, more manpower and time required.

12. Crab cavity test at Point 4 The global scheme is no longer an option for the final HL-LHC, but a prototype cavity could be installed in Point 4 after the tests in SPS. Installation of CC prototype could be: – Coupled to the RF cryogenic upgrade at P4 with 2 K equipment to be added – Scheduled during the LS2 (2018) for possible validation tests during 2019/20/21 (before the LS3 for P1/5 upgrade). Equipment for 2 K refrigeration – a new pumping system must be added: – Additional cooling capacity: ~26 – 30 W @ 2 K per CC module, i.e. 52 – 60 W in total – Warm vs cold pumping: Pumping capacity: ~ 3 g/s  Warm pumping probably more dedicated Warm pumping OK for no continuous test (i.e. during MD period) but lower system availability for continuous operation – Extra cost: ~0.5-1 MCHF depending impurity management – Amplified space – tight integration K. Brodzinski - HiLumi LHC, Frascati 201212

13. Project Process & flow diagram without crab-cavities (4.5 K) Gérard Ferlin K. Brodzinski - HiLumi LHC, Frascati 201213 surface shaft cavern and tunnel

14. P4 upgrade for RF cooling First studies to install a cold box, 6.5 kW @ 4.5 K into UX45 cavern, above RF electrical cabinet Gérard Ferlin et al K. Brodzinski - HiLumi LHC, Frascati 201214

15. SPS and P4 CC tests – schedule K. Brodzinski - HiLumi LHC, Frascati 201215 Tentative planning of P4 cryogenics upgrade and CC integration Remarks/remind: If CC are going to P4 they can be connected with new RF refrigerator but its infrastructure will be operational only during LS2 ( 2 K part to be added) Second option is to feed CC at P4 from existing cryo distribution (2 K infrastructure to be integrated).  Clear decision about CC test at P4 is required to study corresponding requirements with related planning.

16. Crab cavities for the final local scheme Configuration: 2 modules per beam, i.e. 4 per Interaction Points (IP1 & IP5) Installation: during the LS2/3 (2018 – 2022) dedicated to the last phase of HL-LHC project Cooling capacity requirements: – 2 K cooling: ~26-30 W per CC module (i.e. 104-120 W per IP) Energy consumption consideration: – COP @ 2.0 K refrigeration: ~800-1000 W/W, i.e. a consumption of 21-30 kW of electrical power per CC module K. Brodzinski - HiLumi LHC, Frascati 201216

17. Cooling of CC modules at P1 and 5 Two possibilities: – Via the 2 new cryoplants dedicated to the new inner triplets at IP1 and IP5 or – Via the 4 existing adjacent-sector cryoplants The choice will depend strongly on: – the operating temperature of the new Inner Triplets (IT): 4.5 K vs 2 K – the total added heat loads K. Brodzinski - HiLumi LHC, Frascati 201217 Remarks: It is probably preferable to link the CC with new refrigerators for ITs, if not we will recreate currently existing in s3-4 and 4-5 unbalance which has justified upgrade of cryo at P4 Studied schemes of cryogenic upgrade for HL-LHC at P1 and 5 will be presented on Friday 16.11.2012 at 10h00 “Cryogenics for HL-LHC” by Laurent Tavian. Existing Cryo plants New Cryo plant for RFsNew Cryo plant for ITs and … CC Sector 3-4 Sector 4-5 Sector 5-6 LHC RFs

18. Conclusions Prototype crab-cavity testing in SPS: – Test possible from end 2014. – Refrigeration at 2 K: liquefaction capacity of the TCF20 must be measured and sufficient. Additional resources (P + M) must be allocated. – Additional 2 K infrastructure to be built – could be in conflict with the LS1 activities – tight to be integrated. Prototype crab-cavity testing at LHC P4: – Test possible from 2018/2019... or before using TCF20 from SPS BA4 – 2 K cooling (~1 MCHF + 2 FTE + a possible noise-insulated building tension/construction…?). Series crab-cavities for the final HL-LHC local scheme: – Cryogenic implementation during the LHC LS3 (2022) – 2 K cooling via new ITs cryoplants preferable: Option for Matching Section area to be cooled by the same cryoplant Cooling with existing sectors cryo plants not excluded but with load unbalance wrto the other LHC sectors Crab cavity prototype and cryostat study  dedicated meeting will be held in FermiLab on 13-14 December 2012 (key decisions to be taken) K. Brodzinski - HiLumi LHC, Frascati 201218