Alpha particle energy-range studies by a layer removal method in polycarbonate detectors for determining unknown ion energies

Abstract

The aim of this study is to apply a “layer removal method” for alpha energy-range determination in polycarbonate detectors (PC) compared with SRIM software. This method is a precise chemical pre-etching process by which a layer of a certain thickness is removed from an exposed or unexposed PC detector surface before applying electrochemical etching (ECE). A group of 500 μm thick PC detectors was exposed to alpha particles of known fluence (∼1.0 × 104 alphas.cm−2) and ∼0.3–∼5.0 MeV energy range, followed by a pre-etching process at 12 different time intervals in 70% ethylenediamine solution. After the ECE process, alpha track density and diameter were determined. Track density versus removed layer thickness for each alpha energy follows a Bragg type peak after which approaching zero at a known removed layer thickness corresponding to the alpha range. The results also show a linear increase of the mean track diameter as the removed layer thickness increases for each energy. On the other hand, this study confirms a shift in the energy range registration by increasing the thickness of the removed layer. Using this precise method, an unknown energy can be determined by step-by-step thickness removal process until the track density approaches zero. In conclusion, the upper energy of ions emitted in a PFD can be determined. This method is a precise and simple method for ion energy-range determination studies for passive ion spectrometry.