Cryostatic device for cooling a detector

Claim 1

Cryostatic device in which the Joule-Thomson effect is used, for cooling a detector, particularly for target seeking missiles, comprising (a) a pressurized gas source, (b) a countercurrent heat exchanger (68) having a forward flow conduit (40) connected with an inlet end (80) to the pressurized gas source, and return flow passage means in heat conducting contact therewith, (c) an expansion nozzle (44) provided at an outlet end of the forward flow conduit (40), the expanded pressurized gas flowing out through the return flow passage means, (d) a Dewar vessel (46) having an inner and an outer wall (48,50) and surrounding the heat exchanger (68) and the expansion nozzle (44), and carrying on its inner wall (48) in the area of the expansion nozzle (44), the detector (62) to be cooled, characterized in that (e) the inlet end (80) of the forward flow conduit (40) is cooled by additional cooling means formed by Peltier elements (90, 98), (f) the inlet end (80) of the forward flow conduit (40) is mounted on a carrier (82,92) of well heat conducting material in good heat conducting contact therewith, and (g) the carrier (82,92) is mounted through the Peltier elements (90,98) on a heat dissipating base, the cold side of the Peltier elements (90,92) being in contact with the carrier (82,92).