Total cross sections for ionizing processes induced by proton impact on molecules of biological interest: a Classical Trajectory Monte Carlo approach.

H. Lekadir (1) , I. Abbas (1) , C. Champion (1) , J. Hanssen (1)

1 LPMC - Laboratoire de physique moléculaire et des collisions

In the current work, we present a study of ionizing interactions between protons and molecular targets of biological interest like water vapour and DNA bases. Total cross sections for single and multiple ionizing processes are calculated and compared to existing theoretical and experimental results for impact energies ranging from 10keV/amu to 10MeV/amu. The theoretical approach used here combines the characteristics of the well-known Classical Trajectory Monte Carlo method with those of the Classical Over-Barrier framework. In this “mixed” approach, all the particles are described in a classical way by assuming at first that the target electrons are initially treated as virtual particles and only involved in the collision when their binding energy is greater than the maximum of the potential energy of the system {projectile-target}. For water, the obtained results are compared to a large set of data and a good agreement is generally observed especially for impact energies greater than 100keV. Considering the DNA bases, the obtained results are given without any comparison since the literature is till now very poor in terms of cross section measurements.

Mots clés: charge exchange; ionization; biological molecules

Domaines: Physique Atomique [physics.atom-ph]

H. Lekadir, I. Abbas, C. Champion, J. Hanssen. Total cross sections for ionizing processes induced by proton impact on molecules of biological interest: a Classical Trajectory Monte Carlo approach.. The Seventh International Symposium on Swift Heavy Ions in Matter, Jun 2008, Lyon, France. ⟨hal-00252106⟩