CHAMONIX XV QRL installation and first experiences of operation

1. CHAMONIX XVQRL installation and first experiences of operation G. Riddone on behalf of the QRL team AT/ACR-cd Acknowledgements to AT/ACR-op and AT/ACR-in sections, AT/VAC, AB/CO, TS/IC, TS/SU groups for their support and collaboration 2006.01.25

2. Contents • QRL layout • Installation • Main features • Present status • Schedule • Operation  Reception tests • Schedule • Main results • Conclusions 2

3. QRL layout • QRL is a continuous cryostat of ~3.2 km length • no header (4 or 5) sectorisation 9 vacuum sub-sectors (A…I) •  vacuum insulation separate from machine Tested part is marked in blue Vacuum sub-sector “A” A - A C F D G E H B • QRL elements in one sector • ~ 38 service modules • ~ 40 fixed point/vacuum barrier elements • ~ 235 straight pipe elements • ~ 10 steps/elbows • ~ 1-2 cryogenic extensions I 3

4. QRL layout Sector 3-4 Pipe element Service module Sector 5-6 4

5. QRL sector installation • Installation of ~ 700 external supports • Positioning of ~ 325 elements • Welding and testing of ~ 325 interconnections  > 2000 welds • ~ 180 “O” type interconnections (1 butt-weld per header) • ~ 75 “C” type interconnections (2 butt-welds per header) • ~ 70 “A” type Interconnections (3 welds per header) 5

6. QRL sector installation Tool for He leak test • Overall installation: 6 teams • Installation by sub-sectors • Automatic welding for the inner headers • Nominal rate: 20 int./week • Achieved rate: 30 int./week • Manual welding of the external sleeves • Nominal rate: 20 int./week • Achieved rate: 35 int./week • NDT tests • Internal (video camera) and external visual control: 100% • Radiography tests: from 100 % to 10 % as a function of weld quality • Leak tightness tests: 100 % (each weld, each sub-sector, each sector) Head of the machine 6

7. Status of the installation 7

8. Schedule 8

9. Reception tests • QRL tests: • Sector 7-8, sub-sectors A and B: about 700 m • Sector 8-1, full sector: about 3200 m • Tests • Pressure tests • Flushing of the circuits • Cooldown • Instrumentation commissioning • Heat inleak measurements • Warmup 9

10. Reception test schedule 10

11. Pressure test Sector 8-1 11

12. Configuration for flushing and cool-down 12

13. High-flow rate flushing with He New filter (8-1) Old filter (7-8, A-B) Original colour ! 13

14. QRL layout for reception test 14

15. Tests for the sector 8-1 15

16. Cool-down Valve blockage by a “plastic film” coming from header B 16

17. Thermometer validation Header C, SSA: 8 TT fully in accordance 17

18. Heat inleak measurement B, C and D QB,C,D = (mD·hD+mB·hB) - mC·hC (indirect calculation of the mass-flow by using the heaters EH) E and F QEF = mF·(hFout-hFin) + mE ·(hEout-hEin) 18

19. Results for headers E and F • Boundary conditions • Insulation vacuum in the main envelope: • 10-6 mbar (8-1) • 10-5 mbar (7-8) • Headers E and F: 50-75 K • Headers C, D and B: 8-15 K 19

20. Results for headers C, B, D (sector 7-8, A and B) JC = jumper connection JR = junction region • - without JR and without JC ~ 0.25 W/m • JC ~ 50 W  4.2 W/JC • JR ~ 70 W  1 W/m Measurement cross-checked with independent refrigerator input 20

21. Results for headers C, B, D (sector 8-1) QRL with JR and without JC • Boundary conditions • Insulation vacuum in the main envelope: 10-6 mbar • Headers E and F: 50-75 K • Headers C, D and B: 8-15 K Mass-flow cross-checked by using the valve opening Measurement cross-checked with independent refrigerator input 21

22. Results for headers C, B, D (sector 8-1) • - without JR and without JC ~ 0.16 W/m • JC ~ 90 W  2.4 W/JC • JR ~ 35 W  0.4 W/m 22

23. Temperatures of the vacuum jacket 23

24. Conclusions 1/2 • Installation progresses well: • External support installation at 75 % • Element installation at 50 % • Installation in the sectors 3-4 and 5-6 (JR excluded) meets the target rates • At present the main concerns for the installation are: • delay for leak detection and repair • availability of singularities for the sector 1-2 (2 JR  18 elbows/steps) • installation of the QRL in UJ22 and UJ24 and possible interference with magnet transport: tooling for QRL installation shall allow the magnet transport • Pressure tests successfully performed for sectors 7-8 (A+B), 8-1 and 4-5 (without the JR) • Flushing of headers required and sufficient time shall be allocated 24

25. Conclusions 2/2 • Cold reception tests performed for sectors 7-8 (A and B) and 8-1 • Successful thermo-mechanical validation of the QRL design • Thermometer accuracy of about +/- 50 mK, much better than specification (+/- 1 K for T> 6K) • Heat inleaks to 50-75 K (headers E and F) circuit within specification • For sector 7-8 (sub-sectors A and B) heat inleaks to 4-20 K (headers B, C and D) above specification. Possible causes identified: • Higher thermal shield temperature than expected • Higher insulation vacuum than nominal • Not nominal insulation vacuum in the jumpers: impact on the heat flux through MLI • For sector 8-1 heat inleaks to 4-20 K circuit are within specification • Important: Header B heat inleaks within the specification (QRL heat inleaks represents more than 95 % of the corresponding total budget) • Other QRL sectors cold tested with the cryo-magnets: still possibility to measure the heat inleaks to the headers only (at present no allocated time for this test) 25