First-Principles Investigation to Ionization of Argon Under Conditions Close to Typical Sonoluminescence Experiments

Abstract

Mott effect, featured by a sharp increase of ionization, is one of the unique properties of partially ionized plasmas, and thus of great interest to astrophysics and inertial confinement fusion. Recent experiments of single bubble sonoluminescence (SBSL) revealed that strong ionization took place at a density two orders lower than usual theoretical expectation. We show from the perspective of electronic structures that the strong ionization is unlikely the result of Mott effect in a pure argon plasma. Instead, first-principles calculations suggest that other ion species from aqueous environments can energetically fit in the gap between the continuum and the top of occupied states of argon, making the Mott effect possible. These results would help to clarify the relationship between SBSL and Mott effect, and further to gain an better understanding of partially ionized plasmas.

Ultrafast electron dynamics and orbital-dependent thermalization in photoexcited metals

“…III, describing electron dynamics in Ni after an initial excitation, the possibility to include laser-excited electron relaxation in TDDFT through the time-dependent modification of fractional occupation numbers f 0 i in the Hamiltonian should be explored. Additionally, the thermalization dynamics in the absence of the laser field can be obtained artificially by introducing strong ionic motion to the system and thus solving molecular dynamics equations together with Kohn-Sham equations [40].…”

“…Recently it was shown however that TDDFT could indirectly provide a mechanism for the electrons to thermally equilibrate with each other [36]. Moreover the motion of the atoms produce a large number of small electronic transitions affecting the evolution of the electron energy distribution function similar to a thermalization process [34,[37][38][39][40]. For the same reason the external electric potential of a laser pulse contributes to the thermalization of electrons through the photon-electron-ion collisional process and thus TDDFT can reasonably capture the thermalization process during the laser pulse.…”

Molecular dynamics simulation of strong shock waves propagating in dense deuterium, taking into consideration effects of excited electrons

“…However, preceding attempts to do this on the level of the time-dependent density functional theory (TD-DFT) [30][31][32] have shown that this approach is extremely computationally costly. Practically, it is only capable to include tens of atoms in the calculation, which is far less than the required number of atoms to describe the propagation of shock waves.…”

Reconciling ionization energies and band gaps of warm dense matter derived with ab initio simulations and average atom models

“…We performed ab initio calculations for dense carbon and aluminum with the Abinit code [37][38][39][40][41][42]. For both materials, we performed static DFT calculation using perfect lattices (T = 0 eV) and DFT-MD simulations at a finite temperature (T = 12.5 eV).…”