Impact-parameter independent multiple ionization in the proton-neon collisional system

For the collisional systems 0.5 MeV p→BNe and 1 MeV p→Ne multiple-ionization probabilities were measured in dependence on the projectile scattering angle. These measurements (projectile-recoil ion-coincidence) were performed with a two-dimensional position-resolving projectile detector and a recoil-ion time-of-flight spectrometer. The measurement results were compared with the SCA theory and nCTMC calculations. The classical calculations (n-particle Monte-Carlo procedures with classical trajectories) can describe the measured multiple-ionization probabilities in the absolute magnitude very well. From the data analysis the single shell contributions and the strength of the electron capture can be determined. The SCA calculations show good agreement with the determined K-shell ionization probabilities, whereby however they underestimate strongly the L-shell ionization probabilities. This is to be expected, because the ratio of projectile velocity to the velocity of the L-shell electrons lies farly beyond the SCA validity range. These first in the scattering angle differential multiple-ionization probabilities for proton collision on heavy atoms show that the classical Monte-Carlo procedures can describe the kinematics of many-body scattering problems also in heavy targets excellently. (orig.)