Alpha and fission fragment autoradiography with superimposed tissue images in CR-39 plastic

A technique is described by which the distributions of both fissionable and alpha-emitting radionuclides in histological sections of lung are visualised in the nuclear track recording plastic CR-39. Fission fragments and alpha-particles from radionuclides contained within the section register as tracks in CR-39 and an image of the tissue structure is induced, superimposed upon the track distribution, by means of low-energy (less than 1 MeV) alpha-particles from an external 238Pu source. Thus accurate apposition of the track distribution and tissue structure is achieved. The efficiencies of this system for alpha-particle and fission fragment detection are 0.51 +/- 0.09 (SD) and 0.48 +/- 0.08 (SD) respectively.