A PRELIMINARY THERMAL STUDY FOR L3 CGEM BOARD G. Giraudo CGEM-IT workshop IHEP Beijing 13-14 March 2017

2 TIGER CHIPS 0.8 W - 25 mm2 2 ANALOG REGULATORS 0.8 W - 6 mm2 CGEM-IT workshop IHEP Beijing 13-14 March 2017 G.Giraudo INFN Torino

FE1 56x40 mm FE2 56x30 mm FE1+FE2 h≈16 mm d≈4 mm 4 THERMAL PADS NEEDED CGEM-IT workshop IHEP Beijing 13-14 March 2017 G.Giraudo INFN Torino

A COPPER BOX (HEAT EXCHANGER) ADDED TO FE1 BOARD THERMAL CONTACT THROUGH THERMAL INTERFACE MATERIALS (ELECTRICAL INSULATOR) (THERM-A-GAP PARKER CHOMERICS, k=6.5 W/m∙K) (THERMFLOW 777 PARKER CHOMERICS, k=7.7 W/m∙k) DELIVERY & HEXAUST OF THE COOLANT THROUGH SS 316 TUBES & FITTINGS ALL COMPONENTS ARE BRAISED BOX FIXED ON FE1 BOARD WITH SCREWS (not shown) WEIGHT < 50 g CGEM-IT workshop IHEP Beijing 13-14 March 2017 G.Giraudo INFN Torino

Tmax =21.5 oC WATER TIN18 °C 0.5 l/min ΔP=0.05bar THERMAL LOAD=0.8 WATER TIN18 °C 0.5 l/min ΔP=0.05bar THERMAL LOAD=0.8 W CGEM-IT workshop IHEP Beijing 13-14 March 2017 G.Giraudo INFN Torino

DETAILED STUDY: VERY PRELIMINARY TEMPERATURE DROP DUE TO THE GEOMETRY ≈ 8 oC CGEM-IT workshop IHEP Beijing 13-14 March 2017 G.Giraudo INFN Torino

INLET ΔP<0.2 bar ΔT<0.3 °C OUTLET 3 LINES IN - 3 LINES OUT POSITION FOR THE Y MANIFOLDS MUST BE CONSIDERED IN THE WHOLE DESIGN. BEST POSITION: AS CLOSE AS POSSIBLE TO THE HEAT EXCHANGERS VOLUME SAVING SOLUTION: 1 LINE IN - 1 LINE OUT 9+9 HEAT EXCHANGERS GROUPED TOGETHER ΔP≈0.6 bar, ΔT≈1 °C CGEM-IT workshop IHEP Beijing 13-14 March 2017 G.Giraudo INFN Torino

WHAT’S NEXT: PROTOTYPE FOR THE HEAT EXCHANGER Validation of the FEM model Feasibility DESIGN OF THE WHOLE SYSTEM Chiller, Valves, Flow regulators, … INTEGRATION IN BESIII (L1 & L2 BOARDS?) CGEM-IT workshop IHEP Beijing 13-14 March 2017 G.Giraudo INFN Torino