Effect of pre-etching on the registration in CR-39 of electrochemically-etched tracks of protons and alpha particles of different energies

Abstract

The amount of pre-etching needed to register electrochemically-etched (ECE) tracks efficiently in CR-39 varies with the particle LET. This dependence was studied for monoenergetic alpha particles from 1 to 5.5 MeV and protons from 0.4 to 13.8 MeV. Pre-etching must be between upper and lower limits, both of which increase with particle energy. For 6N KOH at 60°C, optimal times varied from 2 to 40 hours for protons up to 6 MeV. Above 6 MeV no ECE tracks were obtained although chemically-etched tracks were visible up to 10 MeV. This behaviour helps to explain the response of ECE CR-39 to neutrons of different energies.