1. W. EbensteinDOE annual review Duke UniversitySeptember, 1998 TRT Barrel Cooling: Electronics  Motivation: u Overheating of electronics causes premature failure  Requirements: u 60 mW per channel u Total for type 1(inner) module ~ 20 W u Want operating T < 50 ºC  Cooling Plan: u Heat generated by IC u through stamp board/banding u through legs/sockets u into cooling plate u to mounting channel/tubing u to cooling fluid

2. W. EbensteinDOE annual review Duke UniversitySeptember, 1998  Current Duke Prototype: u Aluminum cooling plate/tubing u tension plate u insulated box u additional sensors/readout

3. W. EbensteinDOE annual review Duke UniversitySeptember, 1998  From Lund: u ASDBLR & DTMROC dummy boards (pictured here) u Roof boards u Readout and display software

4. W. EbensteinDOE annual review Duke UniversitySeptember, 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)

5. W. EbensteinDOE annual review Duke UniversitySeptember, 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

6. W. EbensteinDOE annual review Duke UniversitySeptember, 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

7. W. EbensteinDOE annual review Duke UniversitySeptember, 1998 TRT Barrel Cooling: Module  Motivation: u Uniform temperature needed inside module for optimum TR function  Requirements: u Type 1 module heating is ~ 7.5 Watts u Want T gradient < 7 ºC  Cooling Plan: u Cooling fluid (same as electronics cooling) flows in tubing running full length of module u Tubing makes good contact inside shell at two opposite corners u Shell has good thermal conductivity (50-100 W/m-K)

8. W. EbensteinDOE annual review Duke UniversitySeptember, 1998  Calculation by BNL: u  T = 8.6 ºC

9. W. EbensteinDOE annual review Duke UniversitySeptember, 1998  Duke experimental studies: u Put real module in insulated box u Heat module with current through straws u Flow cooling water at 24 ºC u Measure T with small thermistors inside module and attached to outside of shell

10. W. EbensteinDOE annual review Duke UniversitySeptember, 1998  Module cooling test chamber:

11. W. EbensteinDOE annual review Duke UniversitySeptember, 1998  Results of experiments: u  T ~ 10 ºC