Optical properties of polyethylene: Measurement and applications

Abstract

The optical properties of polyethylene, obtained from transmission measurements on thin films, are presented for photon energies from 0.5 to 76 eV. The results for the extinction coefficient are combined with calculated values in the soft and hard X-ray regions, and both their internal consistency and their consistency with data obtained previously for polystyrene are verified through a sum rule calculation. Based on these optical data, the mean excitation energy for polyethylene is calculated to be 62eV. A model insulator theory, with parameters fixed by the optical data, is employed to calculate inverse mean free paths and energy losses per unit pathlength for low-energy electrons (10 eV through 10 keV) in polyethylene.