Amorphization of Graphite Under ion or Electron Irradiation
AbstractA transmission electron microscope interfaced with ion accelerators (TEM-Accelerator Facility) in JAERI-Takasaki has been used to get insights into the irradiation-induced amorphization of highlyoriented pyrolytic graphite. Amorphization is induced through lattice disorder under irradiation with electrons or ions at room temperature. The displacement threshold energy is determined as 27 eV and 28 eV from the electron-energy dependence of the amorphization fluence at room temperature and 373 K, respectively. The amorphization fluences in dpa are almost identical for irradiation with various kinds of ions within the experimental error. It indicates the thermal spikes do not have an important role for the amorphization over the energy density between 10-4 to 10-2 eV/atom.