Monte Carlo simulation of electronic energy loss for proton impact on nucleobases

Electronic energy loss distributions for the intermediate velocity protons interacting with the nucleobases is simulated under the local density approximation using classical trajectory Monte Carlo method. Peak energy loss in the range of 50-70 eV is observed irrespective of the target species with strong orientation dependence. The energetics of the energy loss process is discussed in the context of ionization and fragmentation thresholds for all the nucleobases. Using these threshold values, geometric cross sections are calculated and compared with the previously reported experimental and theoretical investigations. Though the models were in reasonable agreement with each other, the experimental data showed large deviation with present as well as previously reported models.