Determination Of Structure Parameters In Atomic Ionization Model By Density Functional Method

For more than half a century,the interaction between lasers and atoms and molecules has attracted widespread attention from scientists.Strong-field physics make it possible to explore the microstructure and ultrafast dynamics of atoms or molecules on shorter time cale and smaller space scale.With laser technology developing,the strength of electric field exceeds the coulomb effect in atoms or molecules,which will generate many non-linear phenomena,such as above-threshold ionization,non-sequential double ionization,higher harmonics generation,etc..Tunneling ionization is the first step of many rescattering phenomena,therefore,the investigation of tunneling ionization is helpful for understanding these strong-field rescattering processes.The experimental results of strong field ionization need to be understood and analyzed with the help of theoretical model.we can theoretically obtain the exact ionization rate of the atom by solving the time-dependent Schr?dinger equation(TDSE).This method can explain experimental data but very time-consuming,so some simpler analytical strong-field ionization models have aroused,such as Ammosov-Delone-Krainov(ADK)theory,Perelomov-Popov-Terent’ev(PPT)theory,and strong field approximation(SFA)theory.Compared with TDSE,ADK and PPT ionization models have the advantages of simpler analytical formula,less computational demand,and higher calculation accuracy.These ionization models have been widely used in strong-field physics and attosecond science.Our main work in this paper is to calculate the structure parameters used in the ADK and PPT ionization models.We numerically calculated the atomic and ion potentials based on the density functional method,and then solved the three-dimensional time-independent Schr?dinger equation using the B-spline basis sets to obtain a wave function with correct asymptotic behavior,the accurate structure parameters are extracted from this wave function in the asymptotic region.the accurate structure parameters of 25 atoms,24 positive ions and 13 negative ions were systematically determined.In addition,The accuracy of structure parameters are carefully examined by comparing the ionization probabilities(or yields)calculated by PPT and ADK models with those of solving the time-dependent Schr?dinger equationand the experimental data.These structure parameters are of great significance for studying the ionization of corresponding atoms and ions for ADK and PPT models.