The Induced Electron Density Effects of Swift Heavy Ions in Polymethyl Methacrylate

Abstract

In this work, we have derived a new model of dielectric function in the Belkacem-Sigmund (BS) approximation by using the Mermin model procedure. The modified model Mermin-Belkacem-Sigmund (MBS) takes into account the Penn gap of the material and the charge states of the projectile. We compare energy loss function with the available experimental optical data and other previous theoretical models. The Bethe f-sum rule was applied and the error ratio did not exceed 1.85%. Herein, the results remained consistent with other published research papers. The MBS model was utilized to calculate the induced electron density fluctuation due to heavy ion motion in polymethyl methacrylate (PMMA) polymers. It was found that the induced electron density fluctuation decreases gradually with increasing particle velocity higher than Bohr velocity and the swift proton transfer less energy to the polymer than slow protons. The wake effects of induced electron density fluctuation around the maximum peak position are also reported in this paper.