A5027156838- Atomic and Molecular Physics
- Atmospheric Ozone and Climate
- Particle Accelerators and Free-Electron Lasers
- Ionosphere and magnetosphere dynamics
- Astro and Planetary Science
- Advanced Chemical Physics Studies
- Planetary Science and Exploration
- Advanced X-ray Imaging Techniques
- Plasma Diagnostics and Applications
- Laser-induced spectroscopy and plasma
- Electron and X-Ray Spectroscopy Techniques
- Spectroscopy and Laser Applications
- Solar and Space Plasma Dynamics
- Particle accelerators and beam dynamics
- Photochemistry and Electron Transfer Studies
- Atmospheric chemistry and aerosols
- Laser-Plasma Interactions and Diagnostics
- Laser Design and Applications
- X-ray Diffraction in Crystallography
- X-ray Spectroscopy and Fluorescence Analysis
- Crystallization and Solubility Studies
- Gyrotron and Vacuum Electronics Research
- Mass Spectrometry Techniques and Applications
- Photocathodes and Microchannel Plates
- Diamond and Carbon-based Materials Research
Flinders University
2011-2023
University of Strathclyde
2010-2023
Cockcroft Institute
2012-2023
Daresbury Laboratory
2012-2023
Townsville Hospital
2021
James Cook University
2021
UCSI University
2021
Center for Free-Electron Laser Science
2014
Universität Hamburg
2014
Australian Research Council
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....
Electron-atom and electron-molecule collisional cross sections are needed in the modeling understanding of phenomena ranging from planetary atmosphere science to industrial applications plasmas. This article reviews Born approximation phenomenological scaling approaches that provide accurate excitation over a range electron impact energies. The methods illustrated for variety atomic molecular systems.
Electrons from the Sun, often accelerated by magnetospheric processes, produce low-density plasmas in upper atmospheres of planets and their satellites. The secondary electrons can further ionization, dissociation excitation, leading to enhancement chemical reactions light emission. Similar processes are driven photoelectrons produced sunlight during daytime. Sunlight solar drive same comets. Thus for both understanding planetary predicting emissions comparison with remote observations it is...
Collisions with electrons from several sources are common throughout planetary atmospheres. While in most circumstances direct electron impact is less significant than solar radiation, collisions have a major influence on the chemistry driven by both photon and particle impact. This review addresses atmospheres, emphasis cases where drives, enhances, or otherwise interacts chemical processes. Understanding of atmospheric processes typically involves computational simulation based theory,...
An unaveraged 3D model of the free electron laser (FEL) is presented which capable modelling interactions with broad bandwidth radiation that includes beam shot-noise and coherent spontaneous emission effects. Non-localised transport throughout modelled self-consistently allowing better systems where a larger energy range required. The FEL interaction can be undulator fields variable polarisation. A modular system allows insertion other magnetic structures, such as chicanes. set working...
We report integral cross sections (ICSs) for electron impact excitation of the A 3Σ+u, B 3Πg, W 3Δu, B' 3Σ-u, a' 1Σ-u, a 1Πg, ω1Δu, C 3Πu, E 3Σ+g and a'' 1Σ+g electronic states N2. The present data, each state, were derived at five incident energies in range 15-50 eV, from earlier crossed-beam differential section (DCS) measurements our group. This was facilitated by using molecular phase shift analysis technique to extrapolate measured DCSs 0° 180°, before performing integration....
A curved-crystal Bragg x-ray spectrometer has been used to measure $K\ensuremath{\alpha}$ or $1s\ensuremath{-}2p$ radiation from highly stripped Fexviii-Fexxv impurity ions in the Princeton large torus tokamak. The sufficient energy resolution (\ensuremath{\lesssim}4 eV at 6400 eV) distinguish between different ionization states of iron by measuring shift x rays. measured wavelengths agree well with theory and spectra solar flares laser-produced plasmas. distribution Fe charge center...
This report describes the conceptual design of a proposed free electron laser test facility called CLARA that will be major upgrade to existing VELA accelerator at Daresbury Laboratory in UK. able number new schemes have been but require proof principle experiment confirm they perform as predicted. The primary focus on ultra short photon pulse generation which take lasers into whole regime, enabling area science emerge.
We have measured absolute elastic scattering and vibrational excitation cross sections for electron impact on ethylene. The experimental data been obtained two different crossed-beam spectrometers they cover the energy range from 1 to 100 eV angles between 10° 130°. Both differential (in angle) energy-dependent measured. also analysed using a molecular phase shift analysis technique in order derive integral momentum transfer sections. Comparison is made with earlier data, where available,...
We report results from measurements for differential and integral cross sections of the unresolved 1B1u 3E2g electronic states 1E1u state in benzene. The energy range this work was 10–200 eV, while angular ∼3°–130°. To best our knowledge there are no other corresponding theoretical or experimental data against which we can compare present results. A generalized oscillator strength analysis applied to 100 200 eV section data, both states, with optical strengths being derived each case....
We report on the results of an exhaustive study valence electronic structure norbornane (C7H12), up to binding energies 29 eV. Experimental electron momentum spectroscopy and theoretical Green’s function density functional theory approaches were all utilized in this investigation. A stringent comparison between orbital distributions found that, among tested models, combination Becke-Perdew a polarized basis set triple-ζ quality provides best representation for 20 orbitals norbornane. This...
Vibrationally excited N 2 is important in determining the ionospheric electron density and has also been proposed to play a role production of NO disturbed atmospheres. We report here predictions absolute vibrational distributions ground electronic state produced by impact excitation, at noon midnight under quiet geomagnetic conditions corresponding aurora IBCII + IBCIII 60°N latitude 0° longitude, altitudes between 130 350 km. These were obtained from model which includes thermal excitation...
We have developed a fast-scanning heterodyne receiver into plasma diagnostic that measures the fundamental cyclotron emission from PLT and thus ascertains time evolution of electron temperature profile. The scans 60-90 GHz every 10 ms is interfaced to computer for completely automated calibrated measurements.
Differential and integral cross sections for electron-impact excitation of the dipole-allowed C (1)Pi D (1)Sigma(+) electronic states nitrous oxide have been measured. The differential were determined by analysis normalized energy-loss spectra obtained using a crossed-beam apparatus at six electron energies in range 15-200 eV. Integral subsequently derived from these data. present work was undertaken order to check both validity only other comprehensive experimental study into processes...
We report measurements of differential and integral cross sections for electron excitation the Schumann–Runge continuum, longest band, second band electronic states in molecular oxygen. The energy range present study is 15–200 eV, with angular section (DCS) from 2 to 130°. A generalized oscillator strength analysis then employed order derive (ICSs) corresponding DCSs, these ICSs are compared relevant scaled Born (BEf-scaling [Y.-K. Kim, J. Chem. Phys. 126, 064305 (2007)]) results determined...
Differential cross sections for 18 excited electronic states and 4 composite in nitric oxide (NO) have been determined incident electron energies of 15, 20, 30, 40 50 eV. These differential were obtained the scattered angle range 10°-90° by analysing energy-loss spectra NO at a number fixed scattering angles within that range. This study appears to be first comprehensive investigation electron-impact excitation reported literature.
Differential and integral cross sections for electron-impact excitation of the dipole-allowed $B\text{ }{^{1}\ensuremath{\Sigma}}_{\mathrm{u}}^{+}$ $C\text{ }{^{1}\ensuremath{\Pi}}_{\mathrm{u}}$ electronic states molecular hydrogen have been measured. The differential were determined by analysis normalized energy-loss spectra obtained using a crossed-beam apparatus at energies 40, 100, 200 eV. Integral subsequently derived from these data. present work was undertaken in order to investigate...
Electron impact excitation of vibrational levels in the ground electronic state and nine excited states NO has been simulated for an IBC II aurora (i.e., ∼10 kR 3914 Å radiation) order to predict number densities band emission intensities. New integral electron cross sections were combined with a measured auroral secondary distribution, populations 10 determined under conditions statistical equilibrium. This model predicts extended distribution produced by radiative cascade from seven...
A pulse of electrons in a photomultiplier sometimes generates succeeding spurious pulses, called afterpulses. These are detrimental to statistical analysis the distribution photocounts. method is outlined determine probability occurrence afterpulses, by frequency output pulses produced constant light. related correct for effect afterpulsing, so that original photocounts can be determined, even if light fluctuating. This correction technique tested application measurements twinkling starlight...