Etching processes in CR-39 and Lexan

Abstract

Abstract The use of plastic materials as particle track detectors is based on the dispersion of the velocity by which the two-phase boundery system solid/fluid (detector-material/etch-solution) shifts along the track and the undisturbed bulk material. The different velocities are usually described by two etch rates; the track etch rate of the radiation damaged material and the bulk etch rate of the undamaged material. These etch rates are the result of highly complex physical and chemical processes. In this report the bulk etch rate is studied in closed microscopic volumina like etch cones of some 10 μm radius and about 100 μm cone lenght. The etch process in these tiny reaction vessels is monitored under optical microscope until chemical equilibrium is reached. Saturation measurements are carried out for CR-39 and Lexan plastic materials. Theoretical stoichiometric simulation calculations and experimental data are compared.