Radiography of surface layers with backdiffused β-rays and photon excited electrons☆

Abstract The use of backdiffused photo- and Compton electrons for radiographic examination of surface layers has been known since the early work done by Trillat . For the same purpose backdifffused β-rays can be applied as pointed out recently. Principles of both radiographic techniques will be described. The dependence of the photographic density on the scattering material and the energy of primary radiation has been assessed. The spatial resolution of the technique has been determined by taking radiographs of the surface of sharp contact edge between two different materials and photometrically measuring the edge spread function. Various possible applications are discussed.