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

Effects of the deep ion-induced modification of highly oriented pyrolytic graphite

“…The effect of ion energy on modification of the sur face layers of carbon materials at high irradiation flu ences is associated with a nearly linear dependence of the average (with respect to the projected range of ions) stationary level of primary radiation damage 〈ν〉, expressed in displacements per atom (dpa), on the ions' energy [14,15]. In addition to energy, the 〈ν〉 level depends on the angle of ion incidence on the tar get.…”

“…For example, studies of an altered surface layer of HOPG (UPV 1T grade) conducted by backscattering spectrometry [12,13] showed that irra diation with argon ions with energies on the order of tens of kiloelectronvolts can (at certain temperatures of the target) result in significant structural and mor phological changes at depths an order of magnitude greater than the projected range of ions within the target. The threshold character (with respect to energy) of these effects in the deep modification of the surface of HOPG at high ion irradiation fluences suggests the presence of threshold radiation damage levels [13][14][15].…”

“…Measuring and analyzing the temperature depen dences of ion-electron emission is an efficient tech nique for in situ monitoring of ion induced structural and morphological changes in the surface layers of carbon materials [4,12,[14][15][16][17]. For example, the authors of [17] irradiated HOPG with argon ions and used the above method to determine the characteristic temperature T t of the ion induced texture transition.…”

Relief evolution of HOPG under high-fluence 30keV argon ion irradiation

“…The thickness of the 20 Â 20 mm UPV-1T plates was 3-5 mm. Sample irradiation was conducted at normal surface incidence (h = 0°) using a massmonochromator of the Institute of Nuclear Physics, Moscow State University [19] according to a similar method used in [6,20]. The ion-current density was 0.3-0.4 mA/cm 2 with a beam cross-section of 0.3 cm 2 , and irradiation fluences uÁt = 10 18 -10 19 ion/cm 2 (u is the incident-ion flux density; t is the time of irradiation 10-100 min).…”

Polyatomic Ion-Induced Electron Emission (IIEE) in Electrospray Thrusters

“…Generally, the temperature dependence of ion impact for conductive surfaces is agreed to be negligible, though this is not true for insulating surfaces [29]. An exception for conductive targets occurs if the surface undergoes a phase change due to annealing, where yield exhibits a step-wise increase at the annealing temperature [88]. A well-controlled experiment by Benka et al [89] with MeV ions found a linear decrease in electron yield with temperature, though the relative change in yield per unit temperature never exceeded 1.2 × 10 −4 K −1 for copper.…”