Isolated radiation damage created along un-etchable tracks in PADC consists of two hydroxyl groups

The objective of the present work is to clarify the damage structure along un-etchable tracks in PADC, by determining the damage density of ether as well as the formation density of hydroxyl group along them. Both the damage density and the formation density have been evaluated by means of FT-IR spectrometry on PADC films before and after the exposures to 30 MeV and 65 MeV proton beams with various fluence. The ratio of the damage density of ether to the formation density of hydroxyl group was about 1:2, which was almost identical to those for protons and He ions with energies of below 6 MeV/u. Futhermore, the ratio was hardly changed even in the case of in vacuum irradiation, where the formation density of hydroxyl group was suppressed. It can be assumed that damage consisting of two isolated hydroxyl groups within a single repeating unit of PADC is hardly to alter its etching properties. The stable and high density formation of such specific damage would enable the development of more sensitive detectors. • ・Damage density for ether loss and formation density of hydroxyl groups were determined. • ・The ratio of the damage denity to the formation density was about 1:2 for 30 MeV and 65 MeV protons. • ・The presence of isolated damage consisting of two hydroxyl groups is evident. • ・This damage is stable but does not contribute directly to etching properties.