The Role of Backdiffused Beta Radiation in Imaging with Beta Emitting Neutron Radiographic Converter Screens

The beta-rays backdiffused from cassette backing material contribute significantly to the neutron radio-graphic image of beta emitting screens used in transfer neutron radiography. The photographic density intensifying factors were assessed as a function of backing material, energy of beta radiation, screen type and thickness, radiographic film parameters and irradiation film exposure geometry. The influence of backing material on the Edge Spread Function in imaging with In converters was studied.