X-Ray Calibration Facility (XRCF)
XRCF Instrument Chamber Thermal Control
 The
design philosophy of the XRCF Thermal Control System is to replicate
the thermal environment of the Advanced X-ray Astrophysics Facility
(AXAF-I) spacecraft in order to perform a detailed calibration of
the AXAF-I optical system. The selected design for the TCS is a
system of cryogenic thermal panels and associated electrical heaters.
The cryogenic panels will be flooded with liquid nitrogen (LN2)
and the electrical heater panels will then be used to modulate the
temperature to the desired 50°F ± 2°F. The system consists of 59
independently controlled zones to provide the required maximum spatial
variation of less than or equal to ±2°F. The TCS is also capable
of performing the bakeout functions in the instrument chamber at
a temperature of 160°F and is also capable of providing a wide range
of thermal environments different from AXAF-I requirements.
Thermal Control Capabilities
| Heater panel inboard emissivity |
greater than and equal to 0.9 |
| Cryopanel outboard emissivity |
greater than and equal to 0.2 |
| Heater panel temperature sensors |
minimum of 3/zone |
| Spatial temperature over zone |
± 2°F |
| Thermal Control Range |
-40°F to +160°F |
| Bakeout Temperature |
+160°F |
Additional information concerning the TCS capabilities can be obtained
by contacting the XRCF facility manager.
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