A5040187923- Atomic and Molecular Physics
- Laser-induced spectroscopy and plasma
- Advanced Chemical Physics Studies
- Mass Spectrometry Techniques and Applications
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Plasma Diagnostics and Applications
- Muon and positron interactions and applications
- Ionosphere and magnetosphere dynamics
- Laser Design and Applications
- Electron and X-Ray Spectroscopy Techniques
- Magnetic confinement fusion research
- Dust and Plasma Wave Phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Nuclear physics research studies
- Atmospheric and Environmental Gas Dynamics
- Astrophysics and Star Formation Studies
- Particle physics theoretical and experimental studies
- Pulsars and Gravitational Waves Research
- Molecular Spectroscopy and Structure
- Quantum, superfluid, helium dynamics
- Nuclear Physics and Applications
Los Alamos National Laboratory
2016-2025
Curtin University
2011-2021
Institut International des Sciences et de Technologie
2015
Australian Research Council
2010
University of Rostock
2010
Johannes Kepler University of Linz
2010
LXCat is an open‐access platform ( www.lxcat.net ) for curating data needed modeling the electron and ion components of technological plasmas. The types presently supported on are scattering cross sections swarm/transport parameters, ion‐neutral interaction potentials, optical oscillator strengths. Twenty‐four databases contributed by different groups around world can be accessed LXCat. New contributors welcome; database retain ownership responsible contents maintenance individual databases....
Starting from first principles, this tutorial describes the development of adiabatic-nuclei convergent close-coupling (CCC) method and its application to electron (single-centre) positron scattering diatomic molecules. We give full details single-centre expansion CCC method, namely formulation molecular target structure; solving momentum-space coupled-channel Lippmann–Schwinger equation; deriving cross sections calculating V-matrix elements. Selected results are presented for hydrogen H2...
Context. Low-energy cosmic rays (<1 TeV) play a fundamental role in the chemical and dynamical evolution of molecular clouds, as they control ionisation, dissociation, excitation H 2 . Their characterisation is therefore important both for interpretation observations development theoretical models. However, methods used so far estimating cosmic-ray ionisation rate clouds have several limitations due to uncertainties adopted networks. Aims. We refine extend previously proposed method...
The convergent close-coupling method has been used to solve the electron-hydrogen molecule scattering problem in fixed-nuclei approximation. Excellent agreement with experiment is found for grand total, elastic, electronic-excitation, and total ionization cross sections from very low high energies. This shows that electronic degrees of freedom provides a complete treatment electron on molecules as it does atoms.
We report the electron impact integrated and differential cross sections for excitation to $b{\phantom{\rule{0.16em}{0ex}}}^{3}{\mathrm{\ensuremath{\Sigma}}}_{u}^{+}, a{\phantom{\rule{0.16em}{0ex}}}^{3}{\mathrm{\ensuremath{\Sigma}}}_{g}^{+}, c{\phantom{\rule{0.16em}{0ex}}}^{3}{\mathrm{\ensuremath{\Pi}}}_{u}, B{\phantom{\rule{0.16em}{0ex}}}^{1}{\mathrm{\ensuremath{\Sigma}}}_{u}^{+}, E,F{\phantom{\rule{0.16em}{0ex}}}^{1}{\mathrm{\ensuremath{\Sigma}}}_{g}^{+},...
Electron-hydrogen scattering in weakly coupled hot-dense plasmas has been investigated using the convergent-close-coupling method. The Yukawa-type Debye-H\"uckel potential used to describe plasma screening effects. target structure, excitation dynamics, and ionization process change dramatically as is increased. Excitation cross sections for $1s\ensuremath{\rightarrow}2s,2p,3s,3p,3d$ $2s\ensuremath{\rightarrow}2p,3s,3p,3d$ transitions total from $1s$ $2s$ states are presented. Calculations...
We have extended the $ab$ $initio$ convergent close-coupling method to electron scattering from vibrationally excited molecular hydrogen ion and its isotopologues. Calculations been performed within adiabatic-nuclei approximation. Results are presented for dissociative excitation ionization as a function of initial vibrational state molecules. Comparison with experiment is excellent across energy range near threshold 1 keV.
The $ab$ $initio$ convergent-close-coupling method has been extended to positron-molecule collisions within the adiabatic (fixed-nuclei) approximation. Application molecular hydrogen at energies from 0.1 1000 eV yielded convergent total ionization and grand cross sections over most of energy range. We find that very large calculations are required for convergence, even in case low-energy elastic scattering, due effects positronium formation. In general, comparison with experiment is good.
The atomic hydrogen target has played a pivotal role in the development of quantum collision theory. key complexities computationally managing countably infinite discrete states and uncountably continuum were solved by using as prototype target. In case positron or proton scattering extra complexity charge exchange was also Most recently, molecular been used successfully molecule for developing corresponding We concentrate on convergent close-coupling computational approach to light...
Abstract We present benchmark integrated and differential cross-sections for electron collisions with H 2 using two different theoretical approaches, namely, the R-matrix molecular convergent close-coupling. This is similar to comparative studies conducted on electron–atom H, He Mg. Electron impact excitation <?CDATA ${\mathrm{b}}^{3}{{\Sigma}}_{\mathrm{u}}^{+}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msup> <mml:mrow> <mml:mi...
Abstract Spectral line-shape models are an important part of understanding high-energy-density (HED) plasmas. Models needed for calculating opacity materials and can serve as diagnostics astrophysical laboratory However, much the literature on line shapes is directed toward specialists. This perspective makes it difficult non-specialists to enter field. We have two broad goals with this topical review. First, we aim give information so that others in HED physics may better understand current...
Context . Galactic cosmic rays (CRs) play a crucial role in ionisation, dissociation, and excitation processes within dense cloud regions where UV radiation is absorbed by dust grains gas species. CRs regulate the abundance of ions radicals, leading to formation more complex molecular species, determine charge distribution on grains. A quantitative analysis these effects essential for understanding dynamical chemical evolution star-forming regions. Aims The CR-induced photon flux has...
Electron-helium scattering in weakly coupled hot-dense (Debye) plasma has been investigated using the convergent close-coupling method. The Yukawa-type Debye-H\"uckel potential used to describe Coulomb screening effects. Benchmark results are presented for momentum transfer cross sections, excitation, ionization, and total sections from ground metastable states of helium. Calculations cover entire energy range up 1000 eV no case various Debye lengths (5--100 ${a}_{0}$). We find that as...
The single-center adiabatic-nuclei convergent close-coupling method is used to investigate positron collisions with molecular hydrogen (${\mathrm{H}}_{2}$) in the ground and first vibrationally excited states. Cross sections are presented over energy range from 1 1000 eV for elastic scattering, vibrational excitation, total ionization, grand cross section. present positron-${\mathrm{H}}_{2}$ scattering length calculated as $A=\ensuremath{-}2.70{a}_{0}$ state $A=\ensuremath{-}3.16{a}_{0}$...
A two-center close-coupling method that includes positronium (Ps) formation channels has been developed for positron scattering on molecular hydrogen. Calculations are performed within the fixed-nuclei approximation. Results grand total, Ps-formation, and direct ionization cross sections presented. In general, good agreement with experiment is seen in all calculated sections.
We use the adiabatic-nuclei molecular convergent close-coupling method to perform calculations of 0.01--1000 eV electrons scattering on $c^{3}\mathrm{\ensuremath{\Pi}}_{u}$, $a^{3}\mathrm{\ensuremath{\Sigma}}_{g}^{+}$, $B^{1}\mathrm{\ensuremath{\Sigma}}_{u}^{+}$, $C^{1}\mathrm{\ensuremath{\Pi}}_{u}$, and $EF^{1}\mathrm{\ensuremath{\Sigma}}_{g}^{+}$ states ${\mathrm{H}}_{2}$ in $v=0$ vibrational level. Elastic, superelastic, ionization, grand-total cross sections are presented, as well for...
A survey of antimatter reactions is presented, including the formation antihydrogen atom and anionic, cationic, molecular species by collisional radiative processes. Our approach rooted in detailed knowledge available for many matter counterpart (hydrogenic) reactions, due to their importance controlling early Universe chemistry. We point out that availability trapped at densities similar those pertaining epoch hydrogen chemistry will soon be available. In addition, using modern atomic...
Abstract Ground state total and partial photoionization cross sections of the O2 molecule have been produced with configuration-average distorted-wave (CADW) approximation, an energy- corrected pseudo independent-atom (PIA) method. The PIA approach is based on molecular orbitals expressed as a linear combination atomic orbitals, utilizes corresponding atomic-orbital sections. Here we use energy-corrected computed using Our results are found to be in good agreement measurements across wide...