Infra-red radiation detectors

摘要

An infra-red radiation detector comprises an envelope in the form of a dewar (1,2) in which a vacuum space (12) is present between an outer wall (2) and inner wall (1) cooled by a cooling element (20). Gas molecules are gettered from the vacuum space (12) by at least one shaped molecular-sorbent porous body (10,10') having a major surface which fits onto and is bonded to a cooled surface (e.g. of a radiation shield 8) associated with the cooled inner wall (1). The shaped getter body (10,10') is secured (e.g. by epoxy adhesive) at its major surface to this cooled surface in a heat-exchange relationship so as to be cooled by the cooling element (20) during operation of the detector. The shaped getter body (10,10') is preferably a moulded annulus of synthetic zeolite material.