文档介绍：Detector Cooling Subsystem
Peter Shirron/Code 552, Jesse Wirth/UC
Preliminary Design Review
October 1-2, 1998
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IPT Members
GSFC University of Chicago
Peter Shirron (lead) Jesse Wirth
Mike Jackson Fred Mrozek
Jim Tuttle Dale Sanford
Tom Hait
Evan Kunes
Responsibilities
GSFC: design, fab and test ADR; define requirements for electronics and
and software; procurement/calibration of thermometers; structural
and thermal modeling (including detectors and optics)
UC: design, fab and test of flight helium dewar, including internal
electrical harnesses and connectors
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Outline
• Cryogenics subsystem requirements
• Flight dewar design
– Mechanical design
– Thermal model
• ADR design
– ADR cycle
– Component requirements, design and analysis
– Performance models
• Development plan
• Risk issues
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Cryogenics Subsystem
Requirements
• Provide cooling for detectors, optics, and mechanisms; structure for
mounting the detectors, optical system, and external electronics
– Structure design will modate all handling and operational loads
• Helium dewar
– As a facility instrument, ease of servicing and operation is a high priority
– Use helium at NBP ( K)
– Hold time: >72 hours standby; >24 hours during operations
– Will remain under vacuum and cold (***@4 K) for duration of flight series
(>3weeks)
– Suspension must be stiff enough that stresses due to vibration, shock loads, or
thermal cycling will not damage or displace detector package and
optomechanical assembly from its nominal position
– Pass FAA conformity pliance
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Cryogenics Subsystem
Requirements
• Detectors must be cold enough to achieve background-limited
performance
–T ≤ K
– Refrigeration
• 100% duty cycle during each mission
• Autonomous operation; maximum setup time < 2 hours
• Detector temperature must be stable enough to avoid gain variations, etc.
• Must be able to operate from a sink temperature of K
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