the dose effectS of residual activity S of thymidine irradiated by 20keV N+ ion beam and of based T released from the irradiated thymidine were studied. It was found that S was related to the irradiated sample’s weight
and that about 50% of the damaged dTR molecules was able to produce based T. The post-treatment of strong alkali or strong acid made this proportion be reduced to 23% and 41% respectively
which showed a tendency contrary to that tinder gamma-ray irradiation.