EMAS Stirling Cooler OperationsFeb 24, 2011
Mike Watson
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E-MAS CryoTel GT Stirling Cooler Operation
• System Conditions• EMAS under active vacuum• Detectors off• Lab environment air around 23-26C• AC unit running pushing air to EMAS HX at inlet temperature around 7-9C• Blower pulling on EMAS HX air outlet running at close to 50 CFM• Environmental cover not installed
• Test Sequence• Cooldown initiated from ambient conditions• Cooled to steady state minimum temperature• Stirling cooler secured, system allowed to warm up
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E-MAS CryoTel GT Stirling Cooler Operation
Tripp Lite Portable AC Unit EMAS Heat
Exchanger
AllStar RB-2 Blower
E-MASTurbo Pumping Station
CFM Probe
E-MAS CryoTel GT Stirling Cooler Operation
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Tripp Lite Portable AC Unit
Environmental Cover
Turbo Pumping Station
CFM ProbeAllStar RB-2 Blower
E-MAS CryoTel GT Stirling Cooler Operation
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E-MAS CryoTel GT Stirling Cooler Operation
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E-MAS CryoTel GT Stirling Cooler OperationFinal test data after Indium installation
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• Notes:• Times listed above do not match previous
charts. The cryocooler was secured at ~2100 which matches 10.98 hours in charts.
• Cryocooler automatically shuts down at 70C (Cooler Temp).
• Cold head Casing to Clamp (W/K) conduction value >2x with the installation of indium over thermal gap pad.
• Earlier testing indicated that there is still value additional air flow.
• AC unit did shut down occasionally, (compressor only, fan still runs) presumably due to a low temperature condition.
• Unit restarted itself within a few minutes and did not require any cold head power adjustments.
We need to watch these calculated values over time to ensure the indium joints are not changing
E-MAS CryoTel GT Stirling Cooler Operation
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• Potential upgrade paths
• Remake fins and clamps• Upgrade to copper• Thicker clamp cross section• Less indium in joint
• Start over with SunPower clamp system• Would likely need some customization• Could integrate a liquid path integral
within copper clamps