Electron beam ionization damage processes in p-terphenyl

Ionization damage leading to atomic displacements has been studied in crystals of p-terphenyl using low-energy electron beams. Significant damage is observed only for beam energies in excess of ∼ 1·5 keV. This can be explained on the basis that carbon K-shell ionization is the dominant process. The effective damage threshold is, however, raised well above the K-shell binding energy by competition with the valence excitation loss process.