Abstract: A sensor/cooling system (20) includes a cold finger (46) with an endcap (54) having an end projection (56) at a first end (44) thereof. The end projection (56) defines a recess (58) in an end of the endcap (54), preferably along a longitudinal centerline (60) of the cold finger (46). A support structure (29) has a platform (30) with a first side (40) and a second side (42) oppositely disposed from the first side (40). The second side (42) is affixed to the end projection (56) of the endcap (54) so as to overlie the recess (58). A sensor assembly (28) is affixed to the first side (40) of the platform (30), a cryogenic cooler (50) is affixed to a second end (48) of the cold finger (46), and a vacuum housing (24) encloses at least the sensor assembly (28).