Generic Cold box for ATLAS Upgrade Tracker Sensors Richard French 17/04/08 11:00ish ? My brain dump of stuff!

Source Detector Electronics/repeater board PM Scintillator 60 mm 20 mm 25 mm 22 mm Sketch of possible dimensions of inside of cool-box, to accommodate 3 layer of detectors with 1 cm separation between them and equipped with source/trigger system (HPK PM series H6780). Latyeral dimensions about 12 cm. H(mm)-W(mm)-L(mm) = mm Gianluigi’s previous (3x layer) box internal dimensions sketch

Cold box specifications Based inside a standard -22°C commercial/domestic mini or full chest freezer. Size depends on likelihood of using box for a full stave later on? If the refrigerator compressor is permanently driven, we can use a 3200 or 3300 CAL controller with a solid state relay operating a electronic heater (pulsing from SSR) to keep the temperature control within +/- 0.5°C. Have made this work very well in past so not new stuff. Changing from a standard R1248 non- hydrocarbon refrigerant gas to a hydrocarbon gas means an operating temperature of -34°C if required with the same accuracy. Use of N² purge to drive dew point even lower if required. Current -30°C cold box used on ATLAS SCT

Questions/ideas etc Assuming that a generic box will be favoured also the most difficult to achieve. Daughter board dimensions: Are they now fixed at 84x72mm (ALIBAVA) To accommodate maximum size of 100x100mm + FEE hybrid / module, do we have a minimum? Is the digital SCT128A dead and buried? Si sensor sizes, how many are there out there? Can a base mount be made for all sensors to be fitted to? It makes the generic idea more attractive then. Can I use a finger to connect a Peltier device (fine control) to the sensor in these configurations, what physical contact is there to the sensor? Is Valencia going to come up with the goods – DAQ R/O etc? Cooling temperature, Is zero °C surface temperature cold enough or should we allow for lower running to match with future thermal environment aspirations? Shielding, has a source been finalised as this could be built as part of a faraday cage. Pumping system, is one required or a feed- through added to box for facility? Use N²purge to drive dew point down if required. Laser excitation abandoned for the moment as windows etc costly, stick with basic PM tube and radioactive source. PMT tubes for excitation, what type and should 1 or 2 be used. Advantages disadvantages? The CERN TC group (Michelle Batisin) are pushing for generic boxes for all CERN work. I want to leave as many options open (Laser, mulitwith the design to accommodate as many extras as and when people require them. In 2008/9 it may be the last year of good funding so is best to get a design that works and will be around for a few years.

Generic solution Assuming use of ALIBAVA daughter board? Box internal sketch to be added. New -34°C freezer (grey or white) plus CAL/SSR with electronic heater mods can be made for under £450! No food or fish dinners from Spain included!

Specific Solution Sketch to be added New New -34°C large freezer plus CAL/SSR and electronic heater can be made for under £600