1. Liverpool 19-20 March 09 Irradiation Meeting. Graham Beck (QMUL) 1 Dissipated Power: Sensor (at -10C, 200V bias, after 10 15 protons/cm 2 ) ~ 1W (×3 for  T ~ 10C or V bias => 500V) Hybrid (20 ABCD250 chips) ~ 10W. (useful? rad.hard?) Baseline Cooling Scheme similar to 1999 (when lower fluence, ~5W hybrid): -Thermal Box -Non-condensing nitrogen atmosphere (slow feed from bottle) -Electric Fans circulate N 2 around devices and Heat Exchanger (HEX) -HEX cooled by remote (o/s beamline) Circulating Chiller. Quantitative test at QML (not final geometry!): Irradiation: Cooling

2. Liverpool 19-20 March 09 Irradiation Meeting. Graham Beck (QMUL) 2 Styrofoam box (75mm thick, 38 litres). Haake Chiller (on floor, 2 x ~1m pipes), 1 litre/min N 2 ( = 1 bottle per week) achieves -14C dew point.

3. Liverpool 19-20 March 09 Irradiation Meeting. Graham Beck (QMUL) 3 From above: Fans, HEX (oil cooler), dummy sensor (kapton foil heaters) + thermocouples, Vaisala temperature/humidity probe …

4. Liverpool 19-20 March 09 Irradiation Meeting. Graham Beck (QMUL) 4 … Flow speed (from hot wire anemometer) is about 2 m/s.

5. Liverpool 19-20 March 09 Irradiation Meeting. Graham Beck (QMUL) 5 Results: Haake bath = -10.5C => Gas at -10C. 10W dissipated in dummy sensor:

6. Liverpool 19-20 March 09 Irradiation Meeting. Graham Beck (QMUL) 6 Temperature rise is proportional to dummy sensor power:  T ~ 1.5C/W => For 1W sensor at -7C => cool gas to -8.5 C (ok) 10W Sensor at -7C + Integrated hybrid => cool gas to -22C (?)

7. Liverpool 19-20 March 09 Irradiation Meeting. Graham Beck (QMUL) 7 Cooling Loads: Sensors 3 x 1W + Hybrid:10W Fans: 10W Conduction from ambient (  T=35C): ~20W (estd.) => sub-total for HEX: ~ 30 – 40W (tested - ok!) Conduction through lagging (2 x 6m pipes) ~ 100W => total for circulating chiller ~ 150W - Cooling power required from chiller is not extra-ordinary - Temperature rise from chiller to test box is an issue (as previously) => Expect to buy new chiller with adequate cooling power and pumping speed.

8. Liverpool 19-20 March 09 Irradiation Meeting. Graham Beck (QMUL) 8 Sensor/Box Arrangement (schematic) Passives, e.g. glue, grease. RPC beam monitor + Activation Foils (Entry and Exit) Thermally insulated box Scan Table (H and V across beam) 3 Sensors (biassed) Angular alignment (H,V) to beam: Necessary? Range, resolution? Check: * space for HEX * range of motion to clear beam. Fans + HEX

9. Liverpool 19-20 March 09 Irradiation Meeting. Graham Beck (QMUL) 9 Where are we? Installing 2 more dummy sensors into test rig – check effect (expect small/tolerable) => Cooling problem under control …. => Ready to design / build box (1+ FTE engineer, 1+ FTE workshop). Sensor support pcbs? Services, feedthroughs, controls.. Need sorting out => see Richard’s list! Future test of sensor + integrated (rad.hard) hybrid probably needs “baseboard” / “stave” with liquid (or evaporative) cooling, similar to final upgrade system.