Response of Photographic Emulsions to Charged Particles and Neutrons

Abstract

Photographic emulsions have found wide application in the field of Pand y,-ray dosimetry. From their initial use for personnel monitoring, film techniques have been expanded to measure Pand y-ray dosage under a wide variety of conditions. For many types of investigations, its small size and high resolving power make a photographic emulsion the most suitable radiation detector. Despite the versatility of film, little has been done to investigate the use of film detectors with neutrons. Studies have been limited largely to personnel monitoring problems, where nuclear-track plates are examined by microscope to determine neutron exposure (1, 2). Rausa has shown that, for thermal neutrons, gross density measurements can be substituted for track counting techniques if the film is covered with shields of cadmium or rhodium (3). He concluded that for fast neutrons conventional film is too insensitive for personnel monitoring. Under conditions of cyclotron or pile irradiation where neutrons are used for biological studies, radiation levels are sufficiently large so that the effect of neutrons on film blackening can be studied. Because the production of neutrons is always accompanied by -y-radiation, film blackening will result from a combination of the two.