Effect of storage on optimum scrapping conditions of the nuclear track detector CR-39

Abstract The effect of store for along time away from the optimum store condition for solid state nuclear track detector CR-39 was studied in this work, after irradiated by - particles emitted from 241Am(1Ci) source with 3.5 MeV energy for 3min. The detector pieces were etched in 4N-6.25N aqueous solution of NaOH maintained at temperature 70 Co for various times from 0.75 hr 6 hr. The results showed that the optimum condition was 5 N for aqueous solution and 3 hr for etching time at temperature 70 Co. The bulk etch rate VB and track etch rate VT and efficiency, sensitivity and the critical angle were calculated.