Scaling rules for the ionization of biological molecules by highly charged ions

Abstract

We investigate scaling rules for the ionization cross sections of multicharged ions on molecules of biological interest. The cross sections are obtained using a methodology presented by Mendez et al (2020 J. Phys. B: At. Mol. Opt. Phys. 53 055201), which considers distorted-wave calculations for atomic targets combined with a molecular stoichiometric model. We examine ions with nuclear charges Z from +1 to +8 impacting on five nucleobases –adenine, cytosine, guanine, thymine, uracil–, tetrahydrofuran, pyrimidine, and water. We investigate scaling rules of the ionization cross section with the ion charge and the number of active electrons per molecule. Combining these two features, we define a scaling law for any ion and molecular target, which is valid in the intermediate to high energy range, i.e. 0.2–5 MeV amu−1 for oxygen impact. Thus, the forty ion-molecule systems analyzed here can be merged into a single band. We confirm the generality of our independent scaling law with several collisional systems.