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Canary Cage Update. LANL Steve Elliott Vic Gehman Vince Guiseppe Keith Rielage. UW Tom Burritt Mark Howe Mike Marino Alexis Schubert John Wilkerson. Canary Cage Overview. Test stand for thermal and mechanical aspects of Majorana Radiative crystal cooling Detector string design
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Canary Cage Update LANL Steve Elliott Vic Gehman Vince Guiseppe Keith Rielage UW Tom Burritt Mark Howe Mike Marino Alexis Schubert John Wilkerson Cryostat Workshop November 29-30, 2007
Canary Cage Overview • Test stand for thermal and mechanical aspects of Majorana • Radiative crystal cooling • Detector string design • Goal is to operate a string of “canary” detectors • Located in LANL basement lab • Cryostat is OHFC copper • Not low mass • Not low background Cryostat Workshop November 29-30, 2007
Canary Cage Design temperature sensors cold finger support ring cryostat lead shield preamps LN dewar cold finger preamp box cold trap detector housing Cryostat Workshop November 29-30, 2007 detector string
Detector Strings • Cryostat has 3-string capacity • Each string can hold 3 detectors • Thermal test string holds 3 detector blanks • Stainless steel for approximate thermal mass and emissivity of Ge crystals • Thermocouple mounted on each crystal • Thermocouple readouts at preamp box Mounting points for temperature sensors Cryostat Workshop November 29-30, 2007
Canary Cooling Cryostat Workshop November 29-30, 2007
RGA Data • October 2007 • After baking cryostat for one day, pumping over a weekend H2O N2 CO2 Cryostat Workshop November 29-30, 2007
Glove Box Cryostat Workshop November 29-30, 2007
Recent Work • LN controller (AMI 286) calibrated and added to Orca to monitor LN consumption • Signal and HV cable in place and wired to feed throughs • Parts ready • Butt splices for signal and HV connections to existing wires on crystal • Teflon tubing for insulation • Baking procedure established and tested for safe temperature • External heat tape • Light bulb inside of dewar • Pumping and baking in progress Cryostat Workshop November 29-30, 2007
Plans for the near future • Add a functioning canary detector • Canberra p-type detector attached to dipstick • 1.5% at 1332 keV • Transfer to an empty detector string • Make the signal and HV connections • Insert into Canary Cage • Possibly replace one stainless steel blank with an old Ge(Li) crystal • Attach a temperature sensor • Eliminate assumptions about thermal properties of germanium • Pump, bake, cool • Make external preamp connections • Bias detector • Characterize detector Cryostat Workshop November 29-30, 2007
Extra info - canary pressure • This was taken in June, before baking and reducing the number of vacuum fittings Cryostat Workshop November 29-30, 2007
Extra info Cryostat Workshop November 29-30, 2007