ATLAS TRT Barrel Design Review, 1998 Barrel TRT Electronics Cooling Chiho Wang Duke University

ATLAS TRT Barrel Design Review, 1998 Barrel TRT Electronics Cooling  Motivation: u Overheating of electronics causes premature failure  Requirements: u 60 mW per channel u Total for type 1 module ~ 20 W u Want operating T < 50 ºC  Heat Transfer Path: u Heat generated by components on ASDBLR & DTMROC stamp board u through stamp board/banding u through legs/sockets u into (tension plate/) cooling plate u to cooling tube/coolan

ATLAS TRT Barrel Design Review, 1998  Current Duke Prototype: u 1.3mm Aluminum cooling plate u 5/32” Aluminum cooling tube u tension plate u thermal insulation box u additional sensors/readout

ATLAS TRT Barrel Design Review, 1998  From Lund: u Simulated ASDBLR & DTMROC stamp boards u Simulated roof boards u Temperature readout and display software

ATLAS TRT Barrel Design Review, 1998  Results of tests: (coolant at 14 ºC) u 1.3 mm cooling plate + all sockets:  ASDBLR: 46 ºC  DTMROC: 48 ºC  roof boards: 38 ºC  cooling, tension plates: ~ 27 ºC u (Typical range: ± 2 ºC)

ATLAS TRT Barrel Design Review, 1998 Barrel TRT Electronics Cooling  Conclusion: u 1.3mm Aluminum cooling plate is sufficient to reduce electronics temperature < 50ºC u Study of using 1mm Aluminum cooling plate in progress (type 3 module).

ATLAS TRT Barrel Design Review, 1998  Remaining issues/improvements: u Mass production of tubing u Attachment of tubing/channel u Heat transfer banding/legs/sockets u Replacement of aluminum cooling plate by pyrolytic graphite (PG):  Motivation: Need to reduce material to get acceptable radiation length

ATLAS TRT Barrel Design Review, 1998  Properties of PG material: u Made by pyrolysis of hydrocarbon gases in a vacuum furnace u Thermal conductivity(in-plane):  PG ~ 400 W/m-K  compare: Cu ~ 400, Al ~ 200 u Expensive  ~ $150k for barrel (PG)  ~ $ 50k with aluminum u Machinability / gluing?  We are exploring