CERN – FP420 - Thermal/cooling - Berend Winter Peltier Cooling Thermal Considerations Berend Winter

CERN – FP420 - Thermal/cooling - Berend Winter Peltier Cooling Peltier Cooling forces a thermal gradient over a series of solid state elements capable of pumping heat Not a very efficient way of cooling (<5-10%) Maximum gradients in order of 70°C (without pumping capacity)

CERN – FP420 - Thermal/cooling - Berend Winter Cooling Power Melcor CP L Hot side 50°CHot side 25°C

CERN – FP420 - Thermal/cooling - Berend Winter Peltier (TEC) Stages – First Cut Don’t panic A single TEC stage is not enough to cool a detector We need a stage between the detector and the wall (TEC1 ) We need a second stage external (TEC2) likely with forced convection Detector heat flux dumped in a flexible link to TEC1 (0.25 W including thermal background radiation TBC) Thermal radiation absorbed by flexible link (0.1 W TBC) The sidewall will sit at an intermediate temperature (10°C???) On the outside we need to dump ~40W per detector plane - very rough estimate TBC

CERN – FP420 - Thermal/cooling - Berend Winter Detector Configuration

CERN – FP420 - Thermal/cooling - Berend Winter Margins Slim but not desperate Requires verification –Some simple breadboard testing is recommendable Melcor Peltier coolers are cheap Thermal straps are simple to make Vacuum chambers are available Thermistors, heaters –Outcome is how much real estate/area we need…