A radiation detection unit includes a housing and isolators unitarily constructed from mechanical energy absorbent material. The housing is attached rigidly to a structure and its major dimensions are selected to exceed corresponding major dimensions of a radiation sensor. The isolators have a body portion and projections extending outwardly therefrom. The body portion engages the radiation detection sensor proximal a respective one of its radiation collection end and its interface end. The projections are disposed intermediate the body portion and an interior surface of the housing and have a distal end contacting the interior surface to carry the radiation sensor in a three dimensional spaced apart relationship to the interior surface. The length of the projections is selected to attenuate substantially mechanical energy that is induced at the distal end and propagates along the length of each projection prior to the propagated energy being incident upon the body portion.