Collision cascade parameters for slow particles impinging on biomolecule targets

Abstract

The binary-collision simulation code COSIPO has been used to investigate the structure of collision cascades that result for 10 keV Xe impinging on an artificial solid with the composition C 3H 5NO to mimic a biomolecule (protein) solid. The electronic and nuclear energy deposition spatial distributions are of similar shape with maxima at the point of 129Xe impact and radial extensions of 0.6 and 0.9 nm and depth extensions of 10 and 14 nm, respectively, for a fall-off to 25% of maximum value. Energy transport in the cascades is chiefly due to Xe primaries and low-order recoils which lead to a highly anisotropic forward-directed cascade. The electronic energy deposition around the track of a 90 MeV 127I particle is estimated for comparison.