The study of graphite disordering using the temperature dependence of ion induced electron emission

The temperature dependences of ion-induced electron emission yield γ(T) under 6–30 keV N_2^+, Ne^+, Ar^+ and 15 keV N^+ high-fluence ion irradiation of polycrystalline graphite at normal ion incidence have been analyzed to trace the structure change dependence depending on irradiation temperature and the level of radiation damage v measured in dpa (displacements per atom). It has been found that, under irradiation at room temperature, the threshold value for graphite lattice disordering equals v_d ≈ 60 dpa for noble gas ions (Ar^+, Ne^+) and ν_d ≈ 40 dpa for N_2^+.