An infrared detector assembly (10) of the type used in munition and night vision systems having an RF activated getter (50). Such detector assemblies (10) include a tubular coldfinger (22) surrounded by a vacuum and which supports infrared detector array (26) and related components. In accordance with this invention, RF getter (50) is located remote from detector array (26) and engages an inner wall surface (56) of a metallic dewar housing (14). The RF getter (50) is activated via RF inductive heating directly through the metal dewar housing (14) such that sensitive IR detector components and hermetic braze joints are kept below their critical temperature. As a result, the present invention provides longer vacuum life and greater operational reliability of infrared detector assembly (10).