Thermal annealing of proton tracks with energies of 4 and 6 MeV in CR-39 polymer detectors

In this paper, we study the thermal annealing of proton tracks of 4 and 6 MeV at temperatures ranging from 150 to 240°C in CR-39 polymer detectors. A special experimental set-up for irradiating the detectors was arranged to obtain adequate proton beams from the Cyclotron CV-28 at IPEN/SP, Brazil. We report experimental data on track densities, track diameters, and activation energies based on current annealing models for the annealing of proton tracks in the energy range investigated. A value of (0.20±0.02)eV was determined as the mean activation energy of the annealing process in CR-39 detectors.