Santa Barbara Research Center

Raytheon Company

Hughes Aircraft Company

Arthur A Eneim

Adam M Kennedy

Wallace Y Kunimoto

Timothy S Romano

Gary B Hughes

Matthew M Skertic

Tom K Evans

Nevil Q Maassen

Kenneth L McAllister

Joseph L Hlava

Janine F Lambe

Monesh S Patel

Farhad I Mirbod

Stephen R Gibbs

A sensor/support system includes a sensor assembly having a planar radiation detector lying parallel to a reference plane, a readout circuit, and an interconnect joining the radiation detector to the readout circuit. The system further includes a support structure, the support structure having a platform with a first side to which the sensor assembly is affixed and a second side oppositely disposed from the first side. A shim is affixed to the second side of the platform. The shim is made of a shim material different from the detector material and the platform material. The shim reduces the strain in the interconnect when the temperature of the sensor/support system is changed, as compared with the strain in the interconnect in the absence of the stabilization structure. The shim is selected such that an in-plane strain in the interconnect, measured parallel to the reference plane, during a required thermal excursion is less than a maximum strain difference over the thermal excursion for the interconnect material in low-cycle fatigue for a design number of cycles evaluated over the required thermal excursion.

Sensor/support system having a stabilization structure affixed to a side of a platform oppositely disposed from a sensor assembly

A vacuum system (20) includes an enclosure (22) having a vacuum-tight wall (26) and an internally threaded aperture (66) through the wall (26). A tip-off fitting (24) has a base (50) with a bore (52) therethrough, a hollow tube (62) fixed to the base (50) with a vacuum-tight seal, such that an interior (64) of the tube (62) is in communication with the bore (52) in the base (50), and an external thread (58) on the exterior of the base (50). The external thread (58) on the exterior of the base (50) is dimensioned to threadably engage the internal thread (68) on the aperture (66). There is a disengageable vacuum sealant (70) such as a layer of indium metal between the external thread (58) of the base (50) and the internal thread (68) of the aperture (66). The vacuum system (20) is evacuated through the tip-off fitting (24) and sealed by closing off the hollow tube (62). At a later time, the vacuum system can be brought to atmospheric pressure and then reseated by replacing the tip-off fitting with another tip-off fitting and repeating the evacuation and sealing.

Semi-permanent vacuum closure with multiple retubulation capability

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).

Fast cooldown cryostat for large infrared focal plane arrays

A dewar (20) useful in rapidly cooling a sensor (28) supported thereon includes a bore tube assembly having a cylindrical dewar bore tube (22) with an end cap (24) at one end to close the bore tube (22). The bore tube assembly is cooled by directing a stream of coolant at the interior of the end cap (24). The sensor (28) is mounted directly to the exterior surface of the end cap (24). A cold shield (34) partially encloses the sensor (28). A cold shield support bracket (38) mounts the cold shield (34) to the cylindrical side walls of the dewar bore tube (22) at a mounting location (36) axially displaced from the end cap (24) and therefore less effectively cooled than the end cap (24), so that heat is extracted from the support bracket (38) and the cold shield (34) less rapidly than from the sensor (28). From an uncooled starting condition, the sensor (28) is cooled to its operating temperature, and the cold shield (34) is cooled to its operating temperature, in about the same time.

Rapid cooldown dewar

Growing community of inventors

Goleta, CA, United States of America

Arthur A Eneim