CREAM Transition Radiation Detector TRD Component Testing Electronics

CREAM Transition Radiation Detector (TRD) Component Testing • Electronics single boards tested -10 C to +50 C • Same design boards flew on TRACER 2003, no failures - high heritage • Vacuum tests on all exposed HV components completed Dec 2003 • Gas system manifolds individually leak checked Aug 2003 • Gas plumbing + manifolds leak checked at 15 psig Jan 2003 • Entire system leak check 8/24/2004 -8/25/2004, good hold time at 10 psig Component flight prep • All boards humisealed • All Reynolds HV inspected for correct o-ring seat • Tie-down of boards in GAK box • Stycast key fasteners

TRD Problem areas and solutions • Initial problems with HV supply manufacturer potting (Aug 2003) • After return/repotting vacuum (3 torr) soak 15 days OK (Nov 2003) • Initial gas valve intermittent probs traced to incorrect driver pulse width fixed • Problems with some TRACER valves in 2003/2004 at -10 C (multiple commands required to close): Replaced stack valves with "clunkers" • UC unpacking TCD/TRD code fully working (finally!)

Possible Hazards/Failures • In vacuum stored energy in gas system ~4, 000 J stored energy • HV breakdown hot spot suspects are Reynolds connectors • Incorrect pump-down pump-up rates could damage TRD

• TRD functional testing • TRD gas tubes do not have passive calibration • Test consists of collecting cosmic ray events - also requires at minimum a functioning TCD trigger • -> test requires 20, 000 events, requires ~1, 000 seconds • -> data analyzed for live channels, gain, light from cer, track fit, etc. TRD testing 4 4 proposed test periods 3 2 1

T-V test issues T-V pump down profile TRD radiator venting designed for balloon launch -> slow pump down, slow pump up. Version 1/20/2004 OK: 800 ->500 torr 15 minutes hold 15 minutes 500 ->250 torr 15 minutes hold 15 minutes 250 ->low torr 15 minutes (ditto going up)

T-V test issues Vacuum residual pressure important • HV Breakdown • Thermal convection?