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Xenon Detector

Xenon Detector. Xenon Detector Group. Contents. Cryostat Construction Detector Preparation Schedule. Cryostat Construction. Xenon Cryostat is NOT DELIVERED YET. Cryostat Construction Cold Vessel. Honeycomb Panel Construction. Thin Window Welding PMT Support Inst. Test

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Xenon Detector

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  1. Xenon Detector Xenon Detector Group

  2. Contents • Cryostat Construction • Detector Preparation • Schedule

  3. Cryostat Construction • Xenon Cryostat is NOT DELIVERED YET Cryostat Construction Cold Vessel Honeycomb Panel Construction • Thin Window Welding • PMT Support Inst. Test • Vacuum Leak Test • Pressure Test • Cryogenic Test • Pressure Test • Low-Temp Test

  4. Week 19-23 June: Warm vessel: Complete welding of all nozzle (3 days). Cold vessel: Complete welding of CF 100 flanges, braze the cooling tube (3 days) Welding test of the windows (2days) New foil fabrications (4 days). Define Honeycomb materials and geometry (2 days) delivery (15 days) Week 26-30 June: Test box preparation: warm window test box (1day); cold window test box (3days). Welding of warm window on the test box (2 days) + helium leak test (1day)+ mechanical test (1day). Machining of cold vessel (5 days). Week 3-7 July: Welding of cold window on the test box (2days)- helium lesk test (1day). New honeycomb delivered – mechanical test cold window (1day). Welding window on cold vessel (2days) Week 10-14 July: Test warm vessel (2days). Helium test of cold window (1day) Honeycomb mounting and cold test preparation (1day) Pressure test cold vessel, 4 bar, (1day) Week 17-21 July: Dry out cold vessel (1day)- helium leak test of metallic sealing on covers (1day). Mounting of the phototube supporting structure (2days) Welding of the L bracket to hold the arches (phototube supporting structure) (1day) Installation of super insulation and temperature sensors (1day) Week 24 -28 July: Alignment and vessel integration (3days) Bellows welding (3day) Week 31July - 4 Agust: Helium leak test on the welds (1day) Internal polishing (3days) Cleaning and dryout (2days) Week 7- 12 August: Preparation and installation of equipmnets for the cryocenic test (1day) Cryogenic test (4days) Week 14- 18 August: Helium leak test of cold vessel (2days) Prepartation of shipmenet (2days) Week 21- 26 August: Delivery to PSI Schedule Reported in the Last Meeting End Oct End Dec

  5. Why is Cryostat Construction Delayed? • Thin window welding and related tests took longer time than expected, which is now successfully completed. • PMT support did not fit the cold vessel wall because of deformation that had appeared during construction process.

  6. ~6mm PMT Support Installation Test • Cold vessel construction procedure • Test was performed on 29/Sep/06, but … Thin window welding Honeycomb panel Installation into the warm vessel Assemble and weld Leak test Machining Reality Ideal Support structure cannot come in • Xenon coming in. • Several mm gap • LXe R.L. 2.89 cm

  7. Protocol Update • Discussion between SIMIC and INFN • Update schedule including remachining of the cold vessel wall • Check points at milestone activities • He Leak Test, Pressure Test, etc. • Assign another SIMIC engineer who can respect the schedule in a cautious manner • In case of schedule slippage without any acceptable reason, we will stop SIMIC and continue at a different manufacturer.

  8. Remachining of the Inner Vessel Wall • Aviolamer (Pianezza, TORINO) • 6-axis milling machine • 3D Coordinate Measuring Machine 632.1 631.6 632.0 634.5 635.9

  9. PMT Support Installation Test • The welded thin window was removed for this procedure • Scraped away the inner wall by 5mm at maximum • PMT support successfully installed • Checked with a gap gauge of 200 mm with the supporting structure installed on 22/Jan/2007

  10. Vacuum Leak Test with Metal Gasket • He vacuum leak test of the cold vesselwith Helicoflex sealing (metal gasket) at a sensibility of 10-9 cc atm/sec on 14/Dec/2006 • OK at the upstream side, but not OK at the downstream side because of • Fixed by filling the hall with a metal piece, and tested again on 18/Dec/2006 welding

  11. Pressure Test • Test up to 4 bar on 19/Dec • Displacement measured at 4 different locations • The test was repeated twice • 1st test OK • 2nd test • Water leak at the upstream flange, which was later found to be due to scratch on the groove. • This was fixed and checked in another vacuum leak test performed on 22/Dec/2006 4 Bar!

  12. 1 4 3 2 Comparison with Simulation • Displacement measured at 4 bar 1.2mm 0.55mm Modeling 1.3 mm Dial. N.1 1.25mm 1.7 mm Dial. N. 2

  13. Thin Window Welding Again • The honeycomb panel and PMT structure are used to guarantee that there is no gaps between them. SIMIC is now drilling the blind thread holes to restrain the panel. • Thin Window Welding • PMT Holder Inst. Test • Vacuum Leak Test • Pressure Test • Cryogenic Test Position of the blind holes

  14. Honeycomb Panel Production

  15. The 1st panel broke down in pressure test as reported in the last meeting New (2nd) panel was designed Honeycomb thickness 19mm  26.5mm High module prepreg 0.75mm 1mm Transition with fabric only Taper Transition Honeycomb panel Thin window welded on the cold vessel Honeycomb Panel – Brief Retrospect 1st honeycomb panel pressure test 1st panel 2nd panel OK on this side

  16. Pressure Test of the 2nd Panel • Pressure testwas stopped at 2.5 bar to check the panel internal surface • Small crack on the surface • The panel was tested again with proper SIM between the panel and test box • Curvature of the panel OK • Curvature of the test box NO • Succeeded to apply up to 4 Bar • Repeated 4 times • Break down at the end SIM SIM Pressure

  17. The 3rd Panel • Internal reinforcement at the edges. • Fiberwith lower module but with a betterElongation (T300, used in aerospace applications with over 20 year service history). • 1.5mm prepreg thickness with 8 piles (1mm in the 2nd panel • Space-approved Resin epoxy (Hysol EA9361) Internal reinforcement “Coca-Cola can” shape

  18. Construction of the 3rd Panel • The 3rd panel requires more intermediated construction steps and a lot of preparation of parts prior to gluing and assembly • Forming the external skin • Forming the honeycomb • Machining the honeycomb • Forming the external skin • Gluing the reinforcement to the central honeycomb in the primary mold • Gluing the external skin to the honeycomb using paste adhesive • Gluing the internal skin to the rest parts with pasteadhesive • Two additional molds are necessary Central honeycomb External skin Internal reinforcement Internal skin

  19. Rohacell Honeycomb glued to the Z reinforcement and rohacell Z reinforcement Inner skin Construction Status of the 3rd Panel • Delivery to Pisa in this week • Pressure and low temperature test soon after that before bringing to SIMIC on 21/Feb Outer Skin

  20. Updated Construction Schedule Cryogenic Test Shipping to PSI

  21. Detector Preparation Xenon Storage Cables and Related Electronics NaI Detector for Pi0 Calibration C-W Proton Acc  Peter’s Presentation Nickel 9 MeV Gamma Generator

  22. GXe pump (10-50L/min) Heat exchanger GXe storage tank Getter+Oxysorb Cryocooler LN2 (100W) LN2 Cryocooler (>150W) Liquid pump (100L/h) Purifier 1000L storage dewar LXe Calorimeter Liquid circulating purifier Xenon Storage • ~900L in liquid, largest amount of LXe ever liquefied in the world • Very stable • Pressure raise 0.003MPa/h w/o cooling • 0.111 MPa  0.2 MPa in 44 hours

  23. Cables and Related Electronics • Signal and HV cables have been already laid down • Signal Splitter and HV power supply are ready, too • HV Controller • GUI for Xe HV control • Runs in monitor mode of meganalyzer • 2D PMT map with markers • Some more functions • Will be tested soon with real HV modules

  24. 60o NaI Detector for Pi0 Calibration • 9 NaI (Tl) Crystals, 62.5x62.5x305mm • Each viewed by 2 APDs (5mm x 5mm) • Electronics Test with MEG DAQ (DRS) at PiE5 • Cosmic-Ray data • Need to improve S/N • APD with larger active are • 2 x 5mm x 5mm  10mm x 10mm COMIC DRS Data

  25. A B C New Neutron BG Measurement • Multiple locations with different detectors (PiE5 in Dec/2006) • Bonner Sphere • NaI activation method with Cd foil wrapping • Total flux 3.7 n /sec/cm2, Thermal flux 0.5n /sec/cm2 • Small enough for Xe Detector PMT operation m beam • 4” x 4” cylinder; • activation technique • thermal and non-thermal separattion by using Cd-wrapping method • Precise measurement of thermal neutron flux and estimate of non thermal neutron flux. • 3He counter • 2”, 3”, 5”, 8”, 10”, 12”spheres • Neutron energy spectrum determination: • sphere response functions • numerical unfolding codes.

  26. m radiative decay Laser 20 cm 3 cm LED Laser Lower beam intensity < 107 Is necessary to reduce pile-ups Better st, makes it possible to take data with higher beam intensity A few days ~ 1 week to get enough statistics g e m (rough) relative timing calib. < 2~3 nsec n n PMT Gain Higher V with light att. Can be repeated frequently p0 gg p- + p  p0 + n p0  gg (55MeV, 83MeV) p- + p  g + n (129MeV) 10 days to scan all volume precisely (faster scan possible with less points) LH2 target alpha Xenon Calibration PMT QE & Att. L Cold GXe LXe e+ g e- Nickel g Generator Proton Acc Li(p,)Be LiF target at COBRA center 17.6MeV g ~daily calib. Can be used also for initial setup 9 MeV Nickelγ-line on off quelle K Bi NaI Illuminate Xe from the back Source (Cf) transferred by comp air  on/off Tl Li(p, 1) at 14.6 MeV F Polyethylene 0.25 cm Nickel plate Li(p, 0) at 17.6 MeV New

  27. 17/June End of Liquefaction Schedule • Available online at • http://meg.web.psi.ch/subprojects/install/xenon.html • April • Cryostat delivery to PSI • Alignment at PiE5 • Start of PMT installation • May • Complete PMT installation • Check electrical connection • Start evacuation • June • Pre-cooling • Liquefaction • Purification • Liquefaction (liquid transfer) will end on 17/June • After the detector is ready, • PMT HV adjust, gain calibration, and a-source (and Cosmic-Ray) data acquisition (2 Weeks) • Proton Acc DAQ (2 Weeks) • p0 run (3 Weeks, 10 Days full DAQ) • Radiative m decay run with lower beam intensity (2 Weeks)

  28. Summary • Cryostat construction • Many problems occurred, but they are getting solved one by one • Honeycomb panel will be delivered to Pisa in this week and tested before bringing it to SIMIC • Cryostat delivery to PSI in April after a cryogenic test • Detector preparation is in good condition • Calibration procedures • pi0 • C-W Acc • Nickel g • Neutron measurement performed again • BG level is expected to be small enough for the xenon detector operation

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