Study On The Double Autoionization Process Of Hole Atom

With the development of X-ray free electron laser, femtosecond-duration，high-intensity hard X-ray pulses can be produced. Hard X-ray can ionize or excitedatomic inner-shell electrons. There is general interest on the atomic inner-shell process.When high-intense hard X-ray interacts with matter, it will produce nonlocalthermodynamic equilibrium (NLTE) plasmas. Double autoionization process has greateffect on chage states distribution, dynamics of charge states and optic properties of theNLTE plasmas. So theoretical study on double autoionization process is an exigentwork for high-intensity X-ray/matter interaction.It is general believed that non-sequential (direct) double autoionization has twophysical mechanisms: shake-off and knock-out mechanism. These mechanisms can beregarded as two steps. The first step of both is single autoionization. Firstly, takegermanium isonuclear as an example, we investigate on the autoionization rate andwidth for2p hole states of Ge5+-Ge21+. Use above results, we investigate on theautoionization resonance widths effect on the L-shell absorption. In representativeexperimental condition, autoionization resonance broadening is the dominantbroadening mechanism.Large-scale configuration interaction were carried out for double autoionizationrates of single1s hole states along neon isonuclear and single2p hole states state ofAr+. The results show that the double autoionization probability (DAP) ofNe+1s2s22p6is5.67%, in good agreement with the experimental results of5.66%and5.97±0.16%, better than previous theoretical results of5.39%and4.0%. For single1shole states along neon isonuclear the double autoionization rate and probability decreaseevidently with the increase of charge state. The autoionization rate is1013s1ofNe+decreases to1011s1ofNe6+, and probability is5.66%of Ne+decreases to0.14%ofNe6+. The DAP of Ar+2p53s23p6is13.80%, very close to theexperimental results of13.2±2%, better than previous theoretical results of0.8%.Ar+2p53s23p6double-autoionized to final state2p63s23p4ofAr3+in theprobability of66.2%via middle state2p63s23p4ofAr2+. We calculate the Augerelectron spectrum after autoionizing, close to the experimental results. As to single1shole states of Ne and single2p hole states of Ar, knock-out is the dominatingmechanism, and the contribution to DAP of shake-off mechanism is smaller than1%.