The principle of nuclear track technique was used in this work. Mica was irradiated by heavy ion of 35Cl produced by tandem accelerator, at the channel L600. The heavy ion beam was scattered and focused on the target window of 3 cm×30 cm. The ion energy The principle of nuclear track technique was used in this work. Mica was irradiated by heavy ion of 35Cl produced by tandem accelerator, at the channel L600. The heavy ion beam was scattered and focused on the target window of 3 cm × 30 cm. The ion energy