High energy radiation detector having improved reflective backing for phosphor layer

An improved high energy radiation detector comprising

• a layer of material responsive to high energy radiation events originating external of the detector for converting the high energy radiation events absorbed in the layer of material to light photons, and
• read-out means in communication with said layer of high energy radiation responsive material for producing signals in response to the light photons emitted by said layer,
• the improvement consisting of
• a member positioned adjacent said layer of high energy radiation responsive material along a first major surface thereof nearest the source of high energy radiation events, said member having a light-reflective first major surface positioned along the first major surface of said layer of high energy radiation responsive material and being defined by a plurality of closely spaced corner reflectors wherein each corner reflector consists of three sides forming substantially identical isosceles triangles having a common vertex and an open base forming an equilateral triangle, the length of one side of the base being less than the thickness of the layer of high energy radiation responsive material, the corner reflectors reflecting rearward traveling light photons in said layer wherein each reflected path is substantially parallel to the incident path of the rearward traveling light photon so that said reflective member provides a high quality reflective surface.