Study of heavy ion tracks in different samples of cellulose nitrate

Samples of cellulose nitrate Daicel (Japanese) and cellulose nitrate (Russian) have been exposed to 40Ar ions of energy 7.4. MeV/N and 50Ti ions of energy 4.9 MeV/N respectively at an angle of 300 from the detector surface using heavy ion cyclotron facilities at JINR Dubna (Moscow), USSR. These samples have been etched in 6.25N NaOH at 600C. The bulk etch rate Vsub(b) has been found at different etching temperatures to determine the activation energies for bulk etching for these plastics. The variation of track length against etching time has been studied to find out the values of total etchable track length for these ions in these detectors. The energy loss and ranges of these ions in these plastics have been computed theoretically. By the comparison of the total etchable track length with the respective value of the theoretically computed range, the values of the critical threshold for these plastics have been found. Finally an attempt has been made to compare the response of these two plastics. (orig.)