Alpha-particle analysis of a triple isotope Pu-239-Am-241-Cm-244 source bynuclear track methodology

This work presents a new approach using nuclear track in solids methodology (NTSM) for the energy analysis of alpha-particles. This method is based on the quantitative relationship between the energy deposited in the polycarb onate by the geometrical parameters of the developed track after the chemic al etching. We used separated calibrated sources of Pu-239 and Am-241 and a mixed source with Pu-239, Am-241 and Cm-244. CR-39 polycarbonate manufactu red by Landauer Inc.(R) was selected as the detector material, because of i ts excellent response to these energies. The chemical etching was done in t wo steps: (a) pre-etching to avoid the irregularities on the surface of the material, and (b) chemical etching to develop the track. In both processes the temperature and pH of the solution need to be very controlled. The geo metrical characteristics of the formed tracks were analyzed automatically b y Digital Image System. The results show a distribution of track diameters as a function of the energies analyzed analogous to the pulses produced on the conventional electronic detection system.