CHAMONIX XV

QRL installation and first experiences of operationG. 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

ContentsQRL layout

InstallationMain featuresPresent statusSchedule

Operation Reception testsSchedule Main results

Conclusions

QRL layoutTested part is marked in blueAGFEDCBHIA - Vacuum sub-sector AQRL is a continuous cryostat of ~3.2 km lengthno header (4 or 5) sectorisation 9 vacuum sub-sectors (AI) vacuum insulation separate from machineQRL elements in one sector~ 38 service modules ~ 40 fixed point/vacuum barrier elements ~ 235 straight pipe elements~ 10 steps/elbows~ 1-2 cryogenic extensions

QRL layout Sector 3-4Sector 5-6Pipe elementService module

QRL sector installationInstallation of ~ 700 external supportsPositioning of ~ 325 elementsWelding 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)

QRL sector installationOverall installation: 6 teams Installation by sub-sectorsAutomatic welding for the inner headersNominal rate: 20 int./weekAchieved rate: 30 int./weekManual welding of the external sleeves Nominal rate: 20 int./weekAchieved rate: 35 int./weekNDT testsInternal (video camera) and external visual control: 100%Radiography tests: from 100 % to 10 % as a function of weld qualityLeak tightness tests: 100 % (each weld, each sub-sector, each sector)

Head of the machine

Status of the installation

Schedule

Reception testsQRL tests:Sector 7-8, sub-sectors A and B: about 700 mSector 8-1, full sector: about 3200 m

TestsPressure testsFlushing of the circuitsCooldownInstrumentation commissioningHeat inleak measurements Warmup

Reception test schedule

Pressure testSector 8-1

Configuration for flushing and cool-down

High-flow rate flushing with HeOriginal colour !New filter(8-1)Old filter(7-8, A-B)

QRL layout for reception test

Tests for the sector 8-1

Cool-downValve blockage by a plastic film coming from header B

Thermometer validationHeader C, SSA: 8 TT fully in accordance

Heat inleak measurementQB,C,D = (mDhD+mBhB) - mChC (indirect calculation of the mass-flow by using the heaters EH)QEF = mF(hFout-hFin) + mE (hEout-hEin) B, C and DE and F

EH

EH

TT

mD , hD

header D

header C

header B

TT

Heat inleaks

mB , hB

mC , hC

TT

TT

EH

EH

TT

TT

TT

Results for headers E and FBoundary conditionsInsulation vacuum in the main envelope: 10-6 mbar (8-1) 10-5 mbar (7-8) Headers E and F: 50-75 KHeaders C, D and B: 8-15 K

[W]Sector 7-8Sector 8-1Calculated24009850Measured2250 +/- 150 9000 +/- 400

Results for headers C, B, D (sector 7-8, A and B)- without JR and without JC ~ 0.25 W/m JC ~ 50 W 4.2 W/JC JR ~ 70 W 1 W/mMeasurement cross-checked with independent refrigerator inputJC = jumper connectionJR = junction region

Results for headers C, B, D (sector 8-1)Boundary conditionsInsulation vacuum in the main envelope: 10-6 mbar Headers E and F: 50-75 KHeaders C, D and B: 8-15 KMeasurement cross-checked with independent refrigerator inputMass-flow cross-checked by using the valve opening

QRL with JR and without JC

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

Temperatures of the vacuum jacket

Conclusions 1/2Installation 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 ratesAt present the main concerns for the installation are: delay for leak detection and repairavailability 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

Conclusions 2/2Cold reception tests performed for sectors 7-8 (A and B) and 8-1 Successful thermo-mechanical validation of the QRL designThermometer 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 expectedHigher insulation vacuum than nominalNot 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 specificationImportant: 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)