A5049059459- Laser-Matter Interactions and Applications
- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Advanced Chemical Physics Studies
- Surface and Thin Film Phenomena
- Laser Design and Applications
- Extraction and Separation Processes
- Electron and X-Ray Spectroscopy Techniques
- Advanced Fiber Laser Technologies
- Laser Material Processing Techniques
- Magnetic confinement fusion research
- Ion-surface interactions and analysis
- COVID-19 Clinical Research Studies
- X-ray Spectroscopy and Fluorescence Analysis
- Quantum optics and atomic interactions
- Oil and Gas Production Techniques
- Plasma Diagnostics and Applications
- Thermal Radiation and Cooling Technologies
- Gastrointestinal motility and disorders
- nanoparticles nucleation surface interactions
- Gut microbiota and health
- Cardiac electrophysiology and arrhythmias
- SARS-CoV-2 and COVID-19 Research
- Pancreatitis Pathology and Treatment
- Atmospheric chemistry and aerosols
Soroka Medical Center
2023
Kaplan Medical Center
2020-2021
Hinchingbrooke Health Care NHS Trust
2016
St George's, University of London
2016
University of Liverpool
1991-2014
Queen Mary University of London
2014
Walton Centre
2014
The University of Texas at Austin
1985-1997
Tampere University of Applied Sciences
1993
University of Warwick
1992
A laser pulse with a power of $\ensuremath{\sim}3$ TW and duration 1 ps has been focused onto gas. Ultrahigh-gradient electron acceleration observed in the laser-produced plasma density $\ensuremath{\sim}{10}^{19}$ c${\mathrm{m}}^{--3}$ when injecting MeV $/c$ electrons. The simulation laser-plasma interaction revealed existence ultrahigh-gradient wake fields excited due to self-modulation its acceleration, consistent experimental results.
Plasma density oscillations (Langmuir waves) in the wake of an intense ( ${I}_{\mathrm{peak}}\ensuremath{\sim}3\ifmmode\times\else\texttimes\fi{}{10}^{17}\mathrm{W}/{\mathrm{cm}}^{2}$) laser pulse (100 fs) are measured with ultrafast time resolution using a longitudinal interferometric technique. Phase shifts consistent large amplitude $\ensuremath{\delta}{n}_{e}/{n}_{e}\ensuremath{\sim}1$) waves at electron plasma frequency were observed fully tunnel-ionized He plasma, corresponding to...
We study femtosecond-laser-pulse-induced electron emission from W(100), Al(110), and Ag(111) in the subdamage regime (1–44 mJ/cm2 fluence) by simultaneously measuring incident-light reflectivity, total yield, electron-energy distribution curves of emitted electrons. The total-yield results are compared with a space-charge-limited extension Richardson–Dushman equation for short-time-scale thermionic particle-in-a-cell computer simulations femtosecond-pulsed-induced emission. Quantitative...
A quantitative structural study of Na and Rb adsorption on Al(111) using normal incidence standing x-ray wave-field triangulation shows that occupies atop sites both systems show a constant adsorbate-substrate bond length over the alkali coverage range 0.12--0.33 monolayer. These results indicate there is directional local bonding in this simple s-p band metal system, no ionic-covalent transition for either system.
We have used dynamical low-energy electron diffraction (LEED) to determine the adsorption site and geometry of surface region for p(2\ifmmode\times\else\texttimes\fi{}2) overlayer potassium adsorbed on Ni(111). The structure consists atoms top Ni with vertical reconstructions in first second substrate layers combined a slight horizontal reconstruction layer. potassium-nickel bond length is found be 2.82\ifmmode\pm\else\textpm\fi{}0.04 \AA{} corresponding rather short effective ``radius''...
Electron temperatures measured in a megajoule theta pinch are found to be limited ∼300 eV over the pressure range 10–50 mTorr and vary during discharge time nonadiabatic manner. The plasma diamagnetism shows rapid decay at of maximum Poynting flux since there is no particle loss this must an energy order input rate. Variation concentration oxygen, which major impurity, by addition known amounts or reduction intrinsic 1.5% magnitude with new pre-ionization technique, indicates rate 2 × 1013...
Physical conditions are obtained to make the propagation velocity of a laser pulse and thus phase excited wake be at any desired value, including that equal or greater than speed light. The provision an active-plasma medium with appropriately shaped allows not only replenishment energy loss field but also acceleration group photons. A stationary solitary solution in accelerated frame is from our model equations simulations thereof for laser, plasma, atoms.
Low-energy electron-diffraction measurements from potassium overlayers on Ni(100) indicate that there are several submonolayer phases for K/Ni(100) below room temperature. Two commensurate solid formed: a c(4\ifmmode\times\else\texttimes\fi{}2) at coverage =0.25 and ${(}_{1}^{2}$ $_{5/3}^{0}$) phase of 0.30. In the range 0.25--0.32, overlayer undergoes uniaxial compression, with adatoms remaining in Ni [110] direction contraction taking place [11\ifmmode\bar\else\textasciimacron\fi{}0]...
The authors have used dynamical low-energy electron diffraction (LEED) to determine the structure of both clean Ni(111) surface and p(2*2) potassium adsorbed on Ni(111). result study indicates that is essentially a truncation bulk crystal. this consists atoms top Ni with slight reconstruction top-layer combined vertical relaxations first second layers Ni. potassium-nickel bond length 2.82+or-0.04 AA corresponding an effective radius about 1.57 AA. This fits well in versus coordination number...
Recent experiments on laser wake-field acceleration have indicated a dramatically enhanced value of the accelerating field created through process Raman forward scattering instability. However, use instability can be improved. If initial growth is from noise, its evolution has problems reproducibility and unpredictable in both time space. We suggest addition small amount one scattered products to pulse or plasma as seed. This allows grow known controllable source, giving predictable...
A principle of the laser wakefield particle acceleration has been tested by Nd : glass system with peak power 30 TW and pulse duration 1 ps. The up to 18 MeV/c demonstrated injecting 1.0 electrons emitted from a solid target an intense impact. corresponding field gradient achieves 1.7 GeV/m.
The adsorption site, and adsorbate-substrate bondlength, has been investigated for the system Al(111)/Rb, using normal incidence standing x-ray wavefield absorption (NISXW), over a range of coverages from 0.12 to 0.33 ML including ordered (2×2) (√3×√3)R30° phases. By measuring both (111) (1̄11) Bragg reflections in NISXW we obtain Rb–Al layer spacings two real space directions can therefore fully determine structure by triangulation. For all phases find atop sites, with coverage-independent...
We study the effects of ionization neutral gases by use short, intense, chirped pulses with various higher-order distortions in frequency domain. Investigations were carried out a one-dimensional, fully relativistic fluid code, which included strong field tunneling and collisional as well quasi-two-dimensional focusing defocusing. The resulting on spectrum are explained terms blue shifting depletion different parts spectral intensity distribution according to their position within laser...
Learning point for cliniciansLoss of taste and smell commonly occurs in patients with SARS-CoV-2 infection.Early administration convalescent plasma therapy may lead to a rapid improvement symptoms, including return sense faster than would occur without therapy.