Depth dependence of IR absorption of MeV and GeV irradiated PMMA and PETP foils

Infrared (IR) absorption spectra are measured as a function of depth for low fluence GeV ion beam irradiated PMMA foils. At all wavelengths the IR absorption always follows the depth distribution of the transferred electronic energy. This holds as well for destructive radiochemical reactions as for the buildup of new aromatic and polycyclic compounds.