Edwin Quashie edited section_Introduction_The_study_of__.tex  over 8 years ago

Commit id: 556782e9ce4b276d2b9056e0d0408eaa118100a1

deletions | additions      

       

In recent times, the development of time-dependent methods have enhanced the diverse study of many body problems involving the slowing down of charged particles either in matters or gases[ref.] The time dependent density functional theory (TDDFT) on the other hand has enjoyed much consideration owing to its electron dynamics both self-consistency and non-perturbative way. [put more paper references here].  Most recently Correa et al [Ref] have reported the role of radiation damage in ion-solid interactions. They have shown that the electronic excitations due to molecular dynamics are quite different from the adiabatic outcome. The inclusion of non adiabatic effects in real calculations remains a challenging problem even today. In 1994 Schleife et al have calculated [Ref.] the electronic stopping by H and He projectile including non-adiabatic interactions employing first principles descriptions. TIt was observed that role of off-channeling trajectories enhances the agreement with the experimental results. Using a quantal method based on TDDFT, Quijada et al [Ref.] have studied the energy loss of protons and anti-protons moving inside metalic Al and obtained good results for the projectile-target energy transfer over a wider energy range. Recently Haque et al [REF.] have calculated stopping cross sections for various media with atomic number Z=2 to 100 using realistic electron density with four fitted parameters and obtained close agreement $(~15\%)$ (~15\%)  with the SRIM data. However, their parametrized model, explains the projectile energy loss in various stopping media reasonably well. We report here an application of the TDDFT that embodies a plane-wave basis set that represent accurately the electron dynamics(put prl, 39,40) for proton impact collision of Cu surface. We have tested the strength of this method to evaluate the electronic stopping $\mathrm(S_e)$. Our findings are compared with those due to stopping and range of ions in matter (SRIM) as well as available experimental values.