TRACK RECORDING PROPERTIES OF THE PLASTIC CR-39 FOR NON-RELATIVISTIC IONS IN THE CHARGE RANGE 6≥Z≥29

ABSTRACT CR-39 plastic has been irradiated with medium charge ions of 9.6 MeV/N from the Manchester linac in order to investigate the track recording properties of the material. We present track etch rate, V T , vs. range for C, N, O and Ne ions and V T as a function of the restricted energy loss, R. E. L., Z eff 2 / β 2 . f( β ) ω o , for C, N, O, Ne, Mg, Al, S, Ar and Cu ions. The R. E. L. is calculated for the best fit value ω o = 200 eV. Etching in 6. 25N NaOH solution was carried out at temperatures of 26°, 40°, 55° and 70°. The activation energy of the bulk material is 0.78 ± 0.03 eV. The sensitivity of the plastic can be adjusted by altering the etch bath temperature. In this experiment we have no evidence for saturation of track etch rate, and a clear indication that the track response in Pershore Mouldings CR-39 and in Homalite are different.