Quantum effects on the formation of negative hydrogen ion by polarization electron capture in partially ionized dense hydrogen plasmas

The quantum effects on the formation of the negative hydrogen ion (H?) by the polarization electron capture process are investigated in partially ionized dense hydrogen plasmas. It is shown that the quantum effect strongly suppresses the electron capture radius as well as the cross section for the formation of the negative hydrogen ion. In addition, it has been found that the electron capture position is receded from the center of the projectile in decreasing the quantum effect of the plasma

Quantum effects on the entanglement fidelity in elastic scatterings in strongly coupled semiclassical plasmas

The quantum effects on the entanglement fidelity in elastic electron-ion scatterings are investigated in strongly coupled semiclassical plasmas. The screened pseudopotential model and partial wave analysis are employed to obtain the entanglement fidelity in strongly coupled semiclassical plasmas as a function of the thermal de Broglie wavelength, Debye length, and projectile energy. It is shown that the quantum effect significantly enhances the entanglement fidelity in strongly coupled semiclassical plasmas. It is also found that the entanglement fidelity increases with increasing the projectile energy. In addition, it is shown that the plasma screening effect increases the entanglement fidelity slightly

Quantum Effects on the Formation of Negative Hydrogen Ion by Polarization Electron Capture in Partially Ionized Dense Hydrogen Plasmas

The quantum effects on the formation of the negative hydrogen ion (H-) by the polarization electron capture process are investigated in partially ionized dense hydrogen plasmas. It is shown that the quantum effect strongly suppresses the electron capture radius as well as the cross section for the formation of the negative hydrogen ion. In addition, it has been found that the electron capture position is receded from the center of the projectile with decreasing the quantum effect of the plasma

Quantum and plasma screening effects on the Wannier threshold law for the double-electron escape in strongly coupled semiclassical plasmas

The quantum and plasma screening effects on the Wannier threshold law for the double-electron escape are investigated in strongly coupled semiclassical plasmas. The renormalized electron charge and Wannier exponent are obtained by considering the equation of motion in the Wannier configuration with the screened pseudopotential model as functions of the de Broglie wavelength, Debye length, and charge of the residual ion. It is shown that the renormalized electron charge significantly increases with an increase in the de Broglie wavelength, especially for small radial distances. It is also shown that the quantum effects enhance the Wannier exponent for the double-electron escape. In addition, the quantum effect on the Wannier threshold law is found to be more important than the plasma screening effect in strongly coupled semiclassical plasmas

Tungsten vs Selenium as a potential source of kilonova nebular emission observed by Spitzer

Infrared emission lines arising from transitions between fine structure levels of heavy elements are expected to produce kilonova nebular emission. For the kilonova in GW170817, strong emission at 4.5 ${\rm \mu m}$ at late times was detected by the Spitzer Space Telescope but no source was detected at 3.6 ${\rm \mu m}$. This peculiar spectrum indicates that there exist strong line emitters around 4.5 ${\rm \mu m}$ and the absence of strong lines around 3.6 ${\rm \mu m}$. To model the spectrum we prepare a line list based on the selection rules in LS coupling from the experimentally calibrated energy levels in the NIST database. This method enables to generate the synthetic spectra with accurate line wavelengths. We find that the spectrum is sensitive to the abundance pattern whether or not the first r-process peak elements are included. In both cases, the synthetic spectra can match the observed data, leading to two possible interpretations. If the first peak elements are abundant a Se III line dominates the flux. If otherwise, W III with Os III, Rh III, and Ce IV can be the main sources. Observing nebular spectra for the future kilonovae in a wider wavelength range can provide more conclusive elemental identification.Comment: 5 pages, 3 figures, submitted to MNRA

Correlation, Breit and Quantum Electrodynamics effects on energy level and transition properties of W54+^{54+} ion

The electron correlation effects and Breit interaction as well as Quantum Electro-Dynamics (QED) effects were expected to have important contribution to the energy level and transition properties of heavy highly charged ions. The ground states [Ne]$3s^{2}3p^{6}3d^{2}$ and first excited states [Ne]3s$^{2}3p^{5}3d^{3}$ of W$^{54+}$ ion have been studied by using Multi-Configuration Dirac-Fock method with the implementation of Grasp2K package. A restricted active space was employed to investigate the correlation contribution from different models. The Breit interaction and QED effects were taken into account in the relativistic configuration interaction calculation with the converged wavefunction. It is found that the correlation contribution from 3s and 3p orbital have important contribution to the energy level, transition wavelength and probability of the ground and the first excited state of W$^{54+}$ ion

Calculations for electron impact ionization of Be atoms and its charged states, Be+ and Be2+

Electron impact triple differential cross section (TDCS) results are reported for the single ionization of Be(2 s), Be(1 s), Be2+(1 s) and Be+(2 s) targets. The differential cross sections have been calculated in the modified distorted-wave formalism under different kinematical conditions for the coplanar emission of electrons. Due to the unavailability of experimental data, we have made a careful comparison of Be and its ions TDCS with the trends of TDCS measured for He and Li targets, which have similar electronic configurations as Be+2 and Be+ respectively. Similarity in the trends of TDCS are observed for He(1 s); Be2+(1 s) targets, Li(2 s); Be+(2 s) and Be(1 s); Be2+(1 s) targets. The effects of iso-electronic and iso-nuclear configurations on collision dynamics are observed in the trends of TDCS