1. Manoj Kumar, B. N. Duttagupta, Rajvir Singh Doohan, S. K. Joshi, A. K. Sagar, L. Chowdhary, Rekhya Naika, Prabhat Kumar Gupta, Vivek Nema, Hemant Kumar Patel and Pradeep Kumar Kush Raja Ramanna Centre for Advanced Technology, Indore 452013, Madhya Pradesh, India CRYOGENIC INFRASTRUCTURE AT RRCAT FOR CHARACTERIZATION OF SCRF CAVITIES AT 2K

2. CRYOGENIC INFRASTRUCTURE AT RRCAT  RRCAT is developing infrastructure for making SCRF cavities for future advanced accelerators.  Characterisation of these cavities require large amount of liquid helium during testing.

3. Cut away section of cryostat pits Liquid Helium vessel parameters Inside diameter: 0.9 m Depth of LHe vessel: 4.86 m Liquid hold. capacity : 3,000 liter

4. Scheme showing cryogenic components Gas bag Recovery compressor LN 2 Dewar HP He gas cylinders Cryo. Transfer line L He Dewar Cryostat 2K pumping station He gas return line

5. Cryostat with cryogenic fluid transfer lines locally made liquid Helium transfer line transfer rate 100 liter/hrs Movable shieldHelium vapor return line Liquid nitrogen line N2 gas return line

6. Commissioning of 145 litres/hour helium liquefier for testing SCRF cavities at 2 Kelvin  Liquefier commissioning completed in three months after receiving at RRCAT – positioning, installation and commissioing  This liquefier is part of the dedicated facility to test SCRF cavities.  Each test requires about 3,000 liters of liquid helium. Liquefier cold box 10,000 liters helium Dewar Control panel

7. 2K pumping station Mechanical booster pumps Vacuum pumps CP120112 m 3 /hr. SP250330 m 3 /hr. Booster pumps EH12001435 m 3 /hr. EH26003110 m 3 /hr.

8. Cavity Test cycle

9. Enlarged view of test cycle

10. Minimum temperature in VTS during testing

11. Commissioning of Vertical Test Facility This facility is operational since November 15, 2013. Result of first test

12. 1.6K

13. Cryogenic team members with muliti fluid transfer lines during fabrication of liquid nitrogen and liquid Helium lines. Enhancement of Cryogenic Infrastructure

14. Helium gas recovery bags were made through local industry. These bags were installed during 2007, since then these are in regular use

15. Outer view: Main Building (extreme right), Compressor room and High + medium pressure helium gas storage shed. Inside View of the main building. Cryogenics Building for testing SCRF Cavities

16. Enhancement of Cryogenic Infrastructure Water capacity of each Cylinder: 2,250 liters ~ 50 x Regular Cylinder Manufactured by M/s Everest Kanto Cylinders Ltd., INDIA Large helium cylinder Equivalent storage capacity 10,000 liters of LHe Quantity:24 Nos Length:12 m Dia.:0.56 m

17. Helium gas recovery compressor [Cap. 210 Nm 3 / hr, 140 bar, 90 kW] Enhancement of Cryogenic Infrastructure

18. Protection against pressurization hazards Multiple relief valves and bursting disks ensure safety of cryostat vessel

19. Transfer of liquid Helium to VTS  LHe and LN 2 multi fluid transfer lines fabricated in-house with multiple bayonet coupling and successfully deployed  Next step is to use supercritical helium transfer for overcoming the problems of heat in-leak during transfer.

20. SUMMARY  VTS is the largest test facilities to test SCRF cavities below 2K nationwide.  The authors acknowledge all the team members of Cryogenics Engineering lab of RRCAT for putting untiring efforts during building, tuning and commissioning of the cryogenic systems together.

21. Thank You!