K‐K electron capture from adenine and CO2 molecule by fast carbon ions using KLL‐Auger electron technique

Abstract

The experimental measurement of total electron transfer cross section in Bragg peak energy region is important to understand energy loss in the biomolecular system. In this study, we have measured state selective, K‐K electron capture and K‐ionization cross sections for adenine (C 5H 5N 5) in collisions with fast (2.5–5 MeV/u) C ions. These are compared with the data for smaller gas molecule, CO 2. These are derived from a study of the KLL‐Auger electron emission yields as a function projectile charge state. The K‐ionization cross‐section (σKI) data are compared with the ECUSAR (united and separated atom [USA] approximation with energy loss [E], Coulomb deflection [C], and relativistic [R] corrections) model calculation. The measured σKI data and the calculations are in good agreement. The K‐K transfer cross‐section (σK−K) data are compared with the CPSSR (perturbed stationary state [PSS] with Coulomb deflection [C] and relativistic corrections [R]) calculation that underestimates the measured data for such symmetric collision system. The energy dependence of σK−K for adenine is found to be flat in contrast to a sharp variation predicted by the model. The K‐transfer cross section is found to be substantial fraction of the K‐ionization.