Charge state of C10and C5energetic cluster ions in amorphous carbon targets: simulations

E Nardi, T A Tombrello
2006 Journal of Physics: Condensed Matter  
We present here detailed simulations of the interaction of energetic C 10 and C 5 clusters at the energies of 1, 2, and 4 MeV per carbon atom with an amorphous carbon target. The spatial evolution of the cluster components is simulated accounting for both scattering and Coulomb explosion. The former is calculated by means of the Monte Carlo method while the latter is computed by means of molecular dynamics. The charge state of the individual cluster components is calculated as a function of
more » ... s a function of penetration depth, and is determined by the competition between electron ionization and recombination. The results of calculations of the effect of the neighbouring cluster components on the suppression of the values of the charge state are presented and compared to the experimental values of Brunelle et al. Charge state suppression calculations for the 2 MeV/C clusters for both C 10 and C 5 agree well with the experimental results for penetration depths of less than about 500 and 250Å respectively, assuming the intracluster Coulomb potential is screened by four target valence electrons. At 4 MeV/C the results are similar although less screening is required; a possible explanation is the inability of the plasma to completely screen the higher velocity projectiles. The 1 MeV/C calculated results however differ in their behaviour from the 2 and 4 MeV/C cases.
doi:10.1088/0953-8984/18/49/026 fatcat:oe6jksyosvhxroutf7wdzdi4sm