The electronic structures of four semiconductor compounds BaCu2S2, BaCu2Se2, BaAg2S2, and BaAg2Se2 are studied by density functional theory using both semi-local and hybrid functionals. The ionization energies and electron affinities were determined by aligning the electronic states with the vacuum level by calculating the electrostatic profile within a supercell slab model. The ionization ener...

The energetics, geometrical and electronic structure, ionization processes, dynamics, and dissociation pathways of neutral and singly and doubly ionized water dimers are investigated with simulations employing the BomOppenheimer local-spin-density functional molecular dynamies (BO-LSD-MD) method. Vertical and adiabatic ionization potentials and dissociation energies and barriers are calculated ...

First, a globally-averaged RF plasma model is used to investigate exit conditions immediately following a RF pre-ionization stage. Analysis shows that reducing pulse duration from 10 to 10 seconds increases peak ion energy fraction by 17% (from 16 to 33%) and doubles final conductivity. Pulse waveforms are square in nature, and ion energy fraction is defined in this work as the percentage of to...

Ionization-assisted spectral broadening of high-energy 10.6 μm laser pulses in a gas-filled hollow waveguide is shown to yield single-cycle pulses with multiterawatt peak powers in the mid-IR. While the highest quality of pulse compression is achieved in the regime of weak ionization, careful management of complex ionization-assisted spectral broadening of guided-wave fields is the key to compr...

An ab initio parametrization of the two-photon double ionization amplitude from an s2 subshell of an atom in a 1S state is presented and used to predict two light polarization effects on photoelectron angular distributions that do not exist in single-photon double ionization: (i) elliptic dichroism and (ii) circular dichroism at equal energy sharing. Estimates for He show large magnitudes for t...

The valence ionization and double ionization spectra of the water molecule, of the water dimer, and the cyclic water clusters (H2O)3 and (H2O)4 are calculated by ab initio Green's function methods and discussed in some detail. Particular attention is paid to the analysis of the development of the spectra with increasing cluster size. Electronic decay following inner valence ionization is addres...

One of the most successful models of ionization is the photo-absorption ionization model . The model assumes that the process of interest is dominated by single-photon exchange which allows one to relate the ionization process to the photo-absorption process for which the data is more readily available. Also the model is restricted to non-relativistic recoil electron, thus it does not include h...

The theoretical model, developed by Khare model, has been modified to calculate the total cross sections for K-shell, L-shell and M-shell ionization of uranium (Z=92) atom due to electron impact at incident electron energy from ionization threshold to 1 GeV. The various calculated cross sections are in remarkable agreement with available experimental data and other theoretical cross sections. P...

We have investigated the full three-dimensional momentum correlation between the electrons emitted from strong field double ionization of neon when the recollision energy of the first electron is on the order of the ionization potential. The momentum correlation in the direction perpendicular to the laser field depends on the time difference of the two electrons leaving the ion. Our results are...

Background: The effectiveness and safety of brachytherapy treatment is mainly concerned with the calibration of sources and their traceability to internationally accepted Standards. Secondary Standard Dosimetry Laboratory (SSDL) does not offer calibration of ionization chambers with gamma-ray spectrum of high dose rate source 192Ir . This work has been carried out to calibrate the high dose rat...