Multiple-electron losses of highly charged ions colliding with neutral atoms

We present calculations of the total and m-fold electron-loss cross sections using the DEPOSIT code for highly charged U(q+) ions (q=10,31,33) colliding with Ne and Ar targets at projectile energies E=1.4 and 3.5 MeV/u. Typical examples of the deposited energy T(b) and m-fold ionization probabilities Pm(b) used for the cross-section calculations as a function of the impact parameter b are given. Calculated m-fold electron-loss cross sections are in a good agreement with available experimental data. Although the projectile charge is rather high, a contribution of multiple-electron loss cross sections to the total electron-loss cross sections is high: about 65% for the cases mentioned.Comment: 6 pages, 4 figure

The DEPOSIT computer code: calculations of electron-loss cross sections for complex ions colliding with neutral atoms

A description of the DEPOSIT computer code is presented. The code is intended to calculate total and m-fold electron-loss cross sections (m is the number of ionized electrons) and the energy T(b) deposited to the projectile (positive or negative ion) during a collision with a neutral atom at low and intermediate collision energies as a function of the impact parameter b. The deposited energy is calculated as a 3D-integral over the projectile coordinate space in the classical energy-deposition model. Examples of the calculated deposited energies, ionization probabilities and electron-loss cross sections are given as well as the description of the input and output data.Comment: 11 pages, 3 figure

Symmetric eikonal model for projectile-electron excitation and loss in relativistic ion-atom collisions

At impact energies $\stackrel{>}{\sim}1$ GeV/u the projectile-electron excitation and loss occurring in collisions between highly charged ions and neutral atoms is already strongly influenced by the presence of atomic electrons. In order to treat these processes in collisions with heavy atoms we generalize the symmetric eikonal model, used earlier for considerations of electron transitions in ion-atom collisions within the scope of a three-body Coulomb problem. We show that at asymptotically high collision energies this model leads to an exact transition amplitude and is very well suited to describe the projectile-electron excitation and loss at energies above a few GeV/u. In particular, by considering a number of examples we demonstrate advantages of this model over the first Born approximation at impact energies $\sim 1$--30 GeV/u, which are of special interest for atomic physics experiments at the future GSI facilities.Comment: 14 pages, 5 figure