Projectile and target scaling of the total ionization cross sections of atoms and molecules

Abstract

A scaling for the total ionization cross sections of atomic and molecular targets by neutral to highly charged projectiles with energies ranging from a few keV/u to many MeV/u is presented, with few free parameters, all velocity independent, and whose values do not vary appreciably for the projectiles and atomic and molecular targets considered here. Another important feature of the proposed scaling is that it has been built considering the characteristics of the collision systems, taking into account the various physical processes that lead to target ionization and the velocity regions where each of them dominates, and performing a smooth transition between them. This scaling describes quite well the existent experimental data covering a broad range of collision systems as diverse as H${}^{+}$ on H, Xe${}^{30+}$ on He, or O${}^{6+}$ on uracil.