Fast cooldown cryostat for large infrared focal plane arrays

• Main Authors: KUNIMOTO; WALLACE Y, ENEIM; ARTHUR A
• Format: Patent
• Language: English
• Published: 17.01.1995
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; BLASTING; COLORIMETRY; COMBINED HEATING AND REFRIGERATION SYSTEMS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; HEAT PUMP SYSTEMS; HEATING; LIGHTING; LIQUEFACTION SOLIDIFICATION OF GASES; MANUFACTURE OR STORAGE OF ICE; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASURING; MECHANICAL ENGINEERING; PHYSICS; RADIATION PYROMETRY; REFRIGERATION MACHINES, PLANTS OR SYSTEMS; REFRIGERATION OR COOLING; SEMICONDUCTOR DEVICES; TESTING; WEAPONS

A dual Joule-Thompson cryostat assembly (10) is provided which includes first and second concentrically aligned cryostats (100) and (102), respectively, which are disposed in the coldwell of a detector assembly (12). Each of the cryostats is connected to a source of pressurized gas which is discharged into the coldwell. The pressurized gas is directed at the components to be cooled such that the relatively high discharge velocity produces a relatively high film coefficient for maximizing heat transfer. Both the inner and outer cryostats, (100) and (102), respectively, of the dual cryostat assembly (10) are designed to direct pressurized gas at an electromagnetic detector (26). In addition, the inner cryostat (100) directs pressurized gas toward the outer cryostat (102) for precooling the outer cryostat (102). Furthermore, the outer cryostat (102) is designed to direct pressurized gas for cooling a coldshield (50) surrounding the detector (26).