Microwave induced chemical etching of CR-39 with KOH etchant: Comparison with chemical etching

Abstract

Abstract Microwave induced chemical etching (MICE) has been successfully employed in reducing the etching duration using NaOH etchant. In this work, the MICE technique has been studied with KOH etchant to investigate the effect on the track development. Chemical etching (CE) has also been performed at different temperatures for a comparison purpose. Neutron irradiated CR-39 track detectors were subjected to stepwise MICE at 4 microwave powers after generating the temperature profile with 200 ml of 6 N KOH. The rate of increase in temperature before attaining the saturation temperature was found to be 3.28, 5.78, 8.2 and 16°C/minute for 300, 450, 600 and 900 W respectively. The image analysis showed the increase in track size with the increase in etching duration in both MICE and CE. The rate of growth of track diameter in MICE was observed to be higher than that of CE. The bulk etch rate as determined by the gravimetric method was found to be higher in MICE than CE. The maximum bulk etch rate in CE at 90°C was 11.81 μ m h−1 which was lower than the minimum bulk etch rate 16.92 μ m h−1 in MICE at 300 W. The bulk etch rate was found to increase with microwave power in MICE and with temperature in CE. Study on the variation of bulk etch rate with microwave power (in MICE) has been carried out and an empirical relation was generated. From the variation of bulk etch rate with temperature, the activation energy of CE for 6 N KOH was found to be 0.70 eV.