Radioluminescent light sources

An extrinsic radioluminescent light source comprising a beta-emitting radioactive element occluded within an amorphous semiconductor matrix, the matrix constituting a secondary electron source responsive to beta emission, and a phosphor positioned to intercept secondary electrons from said electron source to generate light.

A composite intrinsic radioluminescent light source comprising a stratiform structure consisting of alternating layers of (a) an amorphous semiconductor containing an occluded beta-emitting radioactive element, and (b) optically reflective material, the amorphous semiconductor layers being totally enclosed by the reflective material layers except at one end of the structure, whereby light generated within the semiconductor layers is channelled towards said one end by total internal reflection.

A composite extrinsic radioluminescent light source comprising a stratiform structure consisting of alternating light emitting layers and layers of optically reflective material, each said light emitting layer comprising a beta-emitting radioactive element occluded within a semiconductor matrix, the matrix constituting a secondary electron source responsive to beta emission and being sandwiched between phosphor layers positioned to incept secondary electrons from the electron source to generate light, each said light emitting layer being totally enclosed by the optically reflective material save at one end of the structure, whereby light emitted is channelled towards said one end by total internal reflection.