Underlying scaling rules for the ionization of molecules

A. M. P. MENDEZ; C. C. MONTANARI; J. E. MIRAGLIA

Cluj-Napoca

Simposio; 27th International symposium on ion-atom collision; 2021

International Scientific Committee of the International Symposium on Ion-atom Collision

Modeling the ionization of molecules with biological interest by multicharged ions is a challengingtask with critical implications. In the last decade, many comprehensible yet straightforward ab initiomodels have been proposed to obtain reliable values for several DNA and RNA bases. In recent work [1],we combined a continuum distorted wave (CDW) method with a simple molecular stoichiometric model(SSM) to compute the ionization cross sections of over a hundred biologically relevant collisional systems.Further analysis of these results led us to propose three scaling rules [2]. First, we considered themolecular description of the target by taking into account the number of active electrons per molecule,ne. Then, we reduced the nature of the projectile by scaling the cross section with the ion charge, Za, asa function of the reduced impact energy E=Z2􀀀a, with a = 1:2. Finally, we propose a two-folded rule bycombining the ne-scaling with the Za-reduction of the cross section. Figure 1 shows the implementationof this scaling on CDW-SSM calculations for five different charged ions in eighteen targets and on theavailable experimental data. The generality of the scaling proposed is proved to be valid within 35% ina wide energy range by considering a significant number of experimental data sets for other collisionalsystems.