Temperature distribution in an ECAL electronic box

In the design of the ECAL Cooling System a particular interest is represented by the temperature distribution in an electronic box. ECAL is one of the sub-detectors of CMS, it will house 82.728 crystals of lead tungstate, which have to work within a very tight temperature spread of ± 0.05 K. To ensure adequate operating conditions it is of the uppermost importance that the heat dissipated in the electronic boxes is transferred to the power cooling circuit, preventing it to reach the regulating cooling circuit and thus provoking unacceptable temperatures on the crystals. For this reason a simulation of the boxes was performed and analysed.