Raman and near-IR spectral studies have been made on the proton irradiated
CR-39 plastics with 3.4 MeV at fluences ranging from 10(10) to 10(14) ions
cm(-2). The density of -CH2- group began to decrease after the air leak sub
sequent to the irradiation. This implies an important role of the oxygen on
forming the permanent damage along the latent track. Production of OH grou
p and some types of radicals was confirmed by near-IR observations in the a
ir. (C) 2001 Elsevier Science Ltd. All rights reserved.