Loss of carbonate ester bonds along Fe ion tracks in thin CR-39 films

International audienceIn order to identify the chemical modification along nuclear tracks in CR-39 detectors, we have made a series of FT-IR measurements for thin CR-39 plastic films irradiated by Fe ions. The films were reduced in the thickness by long time chemical etchings down to 5 $\mu$m from as-received CR-39 sheets of 100 $\mu$m thick. It enabled us to obtain unsaturated IR spectra. The samples were exposed to 147 MeV Fe ions at HIMAC in air. Amount of loss of carbonated ester bonds due to the exposure was assessed from the changes in the absorbance of C=O and C-O-C bonds with Fe fluence. The assessed G-value for destroy of carbonate ester bonds was found to be about 10 (scission/100eV)