Electron loss from 0.74 and 1.4 MeV/u low-charge-state argon and xenon ions colliding with neon, nitrogen, and argon

Absolute total, single, and multiple electron loss cross sections are measured for Ar"+-, Ar"2"+-, and Xe"3"+- Ne, N_2, Ar collisions at 0.74 and 1.4 MeV/u. In addition, a many-body Classical Trajectory Monte Carlo model was used to calculate total and multiple electron loss cross sections for Ar"+ impact. For N_2 and Ar targets, excellent agreement between the measured and calculated cross sections is found; for the Ne target the experimental data are approximately 40% smaller than the theoretical predictions. The experimental data are also used to examine cross section scaling characteristics for electron loss from fast, low-charge-state, heavy ions. It is shown that multiple electron loss increased the mean charge states of the outgoing argon and xenon ions by two and three respectively. The cross sections decreased with increasing number of electrons lost and scaled roughly as the inverse of the sum of the ionization potentials required to sequentially remove the most weakly bound, next most weakly bound, etc., electrons. This scaling was found to be independent of projectile, incoming charge state, and target. In addition, the experimental total loss cross sections are found to be nearly constant as a function of initial projectile charge state. As a function of impact energy, the theoretical predictions yield an E"-"1"/"3 behavior between 0.5 and 30 MeV/u for the total loss cross sections. Within error bars the data are consistent with this energy dependence but are also consistent with an E"-"1"/"2 energy dependence. (orig.)Available from TIB Hannover: RO 801(03-24) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Electron stripping cross sections for fast, low charge state uranium ions

Cross sections for projectile electron loss for U"1"0"+ and U"2"8"+ colliding with H_2, N_2 and Ar were calculated using the n-body classical trajectory Monte Carlo method. The calculations include electrons on both nuclear centers and all electron-electron and electron-nuclear interactions between centers. Multiple ionization is inherently included in these many electron calculations. Overall, except for the H_2 target where the projectile stripping is overestimated by a factor of two, the calculated cross sections are in reasonable accord with available data and the recent beam lifetime measurements from GSI-Darmstadt. For energies less than 100 MeV/u, the N_2 and Ar cross sections do not scale as E"-"1"."0 as predicted by one-electron theories. (orig.)Available from TIB Hannover: RO 801(04-17) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman