1. Thermal aspects Unité mixte de recherche CNRS-IN2P3
Université Paris-Sud Orsay cedex
Tél. :
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2. Cooling for CLAS-DVCS => HPS ECAL
Based on « Thermal design for the CLAS-DVCS calorimeter » September 2004
Copper serpentines on the thermal enclosure
Flow map inside the DVCS ECAL
Beam
Flow split
ECAL
top
Preamps
Flow map inside the HPS ECAL
=> minimize the pressure drop to get low delta T°
bottom
NESLAB chiller RTE740
~700 W cooling
3 0.5 bars

3. Power summary for CLAS-DVCS => update for HPS ECAL
Based on « Thermal design for the CLAS-DVCS calorimeter » September 2004
The crystals are
stabilized at 18°C
Front plate
P = 2.31W
Top cover
and cradle
P = 5.83 W
Back plate with serpentine = thermal shield
Evacuation of air
Circulation of cooled
nitrogen at low flow
Thermal components and amounts of thermal power to dissipate by cooling system
The total power of this system is 86.7 W
Outside temperature :
30°C with low fan air
Transient cooling
of crystals
in some hours
P = 11.5 W
53 W of heating power by electronics preamplifiers
Back covers and plate P=5W
Cooling panel
in the center
All elements in blue are cooled at 17°C minimum to obtain 18°C on crystals
Convection exchange coefficient
h = 7.59 W/m².K
Links with outside
(mother board, supports P = 5W)
Radiation
P = 4 W
Power summary for the HPS ECAL
ECAL
top
Preamps
bottom
Transient cooling of crystals
in some hours P = 5.75 W
26.5 W
Links with outside
(mother board, supports)
P = 5W
Front plates P=2.3W
Covers P=12.4W
Radiation
P=5W
Total ~89W for the HPS ECAL

4. Schedule Unité mixte de recherche CNRS-IN2P3
Université Paris-Sud Orsay cedex
Tél. :
Fax :

5. 1 ECAL DVCS = 2 ECAL HPS + Vacuum chamber
Still lots of things to integrate. It is not forgotten !!
Alignment targets with the JLAB laser tracker
Thermal sensors ….

6. Schedule