Stopping power of plasma free and bound electrons using dielectric formalism

Abstract

In this work, a method is proposed that accounts for the stopping power of free and bound electrons of a partially ionized plasma. To formulate this method, the well-known dielectric formalism is used, combining a dielectric function of quantum plasmas, which includes temperature, for free electrons, and the shellwise local plasma approximation (SLPA) for bound electrons. Since few experimental data are available for plasmas, our method calculations at T= 0 for solids are compared with SRIM code. The agreement with experimental data is excellent. Also, a cold gas target is considered at different ionization states; results show the expected behavior, but with a little overestimation of the stopping peak and underestimation in the low energy region. Finally our results for plasmas at diverse conditions of temperature are compared with other methods from the literature that contemplate bound electrons explicitly: Mehlhorn, Zimmerman and Unified Wave Packet models. Differences observed between our method, and Mehlhorn and Zimmerman models can be explained by the limited range of application of these old models. In contrast better agreement is obtained when our method is compared with Unified Wave Packet model. These comparisons also serve to prove the validity of our method in different elements.