Electron Removal Processes in Proton-Methane Collisions

We investigate electron removal processes in the proton-methane collision system in the 20 keV to a few MeV energy regime. The two-centre basis generator method is used within the independent electron model to study this problem. Results for net capture and ionization are compared with available experimental and theoretical studies as well as with results obtained from Bragg's additivity rule. Good agreement is observed at high energies. At lower energies the situation is less clear. However, for ionization at intermediate energies we achieve good agreement with experimental results when we take target excitation into account.