Revealing spontaneous fission tracks in zircon by H2SO4
HNo3 and HCl mixed with an equivolume 40% HF respectively at 150℃ or 190℃ has been compared. Respective plateaus of track density in various etching conditions were found. The result indicates that the effect of HNO3 + HF system is better than others and it is better at 190℃ than at 150℃