Degradation of polystyrene thin films under d, He-4 and C-12 irradiation studied by ion beam analysis: Effects of energy loss, sample thickness and isotopic content

Changes in atomic composition (C, H and D) of thin polystyrene films under d, He-4 or C-12 irradiations were studied by nuclear reaction analysis (NRA) and elastic recoil detection analysis (ERDA) for ion energies between 150 and 2500 keV, corresponding to stopping powers 5 to 104 eV/Angstrom. A multiscale setup was used to study atomic losses in real lime during irradiation. It was shown that the first ion interacting with previously unirradiated polymer already produces matter losses; that no stable limit state exists at high doses; that there is a steep increase of losses above dE/dx approximate to 35 eV/Angstrom for the ions studied; that losses are thickness dependent; that H losses are always larger than D ones, without any influence of initial chemical bonding of these atoms. These results are briefly discussed.