A5070829382- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- High-pressure geophysics and materials
- Laser Design and Applications
- Atomic and Molecular Physics
- Nuclear Physics and Applications
- Magnetic confinement fusion research
- Ion-surface interactions and analysis
- Laser Material Processing Techniques
- Advanced X-ray Imaging Techniques
- Dust and Plasma Wave Phenomena
- Pulsed Power Technology Applications
- Particle Accelerators and Free-Electron Lasers
- Plasma Diagnostics and Applications
- Cold Fusion and Nuclear Reactions
- Diamond and Carbon-based Materials Research
- Ionosphere and magnetosphere dynamics
- Electron and X-Ray Spectroscopy Techniques
- Advanced Optical Sensing Technologies
- Particle accelerators and beam dynamics
- Energetic Materials and Combustion
- Orbital Angular Momentum in Optics
- Radiation Therapy and Dosimetry
- Astro and Planetary Science
University of Oxford
2015-2024
John Adams Institute for Accelerator Science
2016-2024
Isaac Newton Institute for Mathematical Sciences
2016-2024
Rutherford Appleton Laboratory
2014-2023
University of Alberta
2022
University of Rochester
2022
Energetics (United States)
2022
Princeton University
2022
Lawrence Livermore National Laboratory
2022
Central Laser Facility
2011-2020
Protons with energies up to 18 MeV have been measured from high density laser-plasma interactions at incident laser intensities of 5x10(19) W/cm(2). Up 10(12) protons greater than 2 were observed propagate through a 125 &mgr;m thick aluminum target and measurements their angular deflection made. It is likely that the originate front surface are bent by large magnetic fields which exist in interior. To agree our these would be excess 30 MG generated beam fast electrons also observed.
The interaction of a 1053 nm picosecond laser pulse with solid target has been studied for focused intensities up to 1019 W cm−2. maximum ion energy cutoff Emax (which is related the hot electron temperature) in range 1.0–12.0 MeV and shown scale as Emax≈I1/3. temperatures were 70–400 keV 5×1018 cm−2 an indication high absorption energy. Measurements x-ray/γ-ray bremsstrahlung emission suggest existence at least two temperatures. Collimation plasma flow observed by optical probing techniques.
Abstract Twisted Laguerre–Gaussian lasers, with orbital angular momentum and characterized by doughnut-shaped intensity profiles, provide a transformative set of tools research directions in growing range fields applications, from super-resolution microcopy ultra-fast optical communications to quantum computing astrophysics. The impact twisted light is widening as recent numerical calculations provided solutions long-standing challenges plasma-based acceleration allowing for high-gradient...
Electron transport within solid targets, irradiated by a high-intensity short-pulse laser, has been measured imaging K(alpha) radiation from high- Z layers (Cu, Ti) buried in low- (CH, Al) foils. Although the laser spot is approximately 10 microm [full width at half maximum (FWHM)], electron beam spreads to > or =70 FWHM <20 of penetration into an Al target then, depths >100 microm, diverges with 40 degree spreading angle. Monte Carlo and analytic models are compared our data. We find that...
When a laser pulse of intensity 10(19) W cm(-2) interacts with solid targets, electrons energies some tens MeV are produced. In tantalum target, the generate an intense highly directional gamma-ray beam that can be used to carry out photonuclear reactions. The isotopes 11C, 38K, (62,64)Cu, 63Zn, 106Ag, 140Pr, and 180Ta have been produced by (gamma,n) reactions using VULCAN beam. addition, laser-induced nuclear fission in 238U has demonstrated, process which was theoretically predicted at...
The first evidence of x-ray harmonic radiation extending to 3.3 \AA{}, 3.8 keV (order $n>3200$) from petawatt class laser-solid interactions is presented, exhibiting relativistic limit efficiency scaling ($\ensuremath{\eta}\ensuremath{\sim}{n}^{\ensuremath{-}2.5}--{n}^{\ensuremath{-}3}$) at multi-keV energies. This holds up a maximum order, ${n}_{\mathrm{RO}}\ensuremath{\sim}{8}^{1/2}{\ensuremath{\gamma}}^{3}$, where $\ensuremath{\gamma}$ the Lorentz factor, above which an intensity...
The angular distribution of bremsstrahlung gamma rays produced by fast electrons accelerated in relativistic laser-solid interaction has been studied photoneutron activation copper. We show that the gamma-ray beam moves from target normal to direction k(laser) vector as scale length is increased. Similar behavior found also 2D particle-in-cell simulations.
Novel measurements of electromagnetic radiation above 10 MeV are presented for ultra intense laser pulse interactions with solids. A bright, highly directional source γ rays was observed directly behind the target. The were produced by bremsstrahlung from energetic electrons generated during interaction. They measured using photoneutron reaction [63Cu(γ,n)62Cu] in copper. resulting activity coincidence counting positron annihilation which decay Cu62. New at 1019 W cm−2 also presented.
We report measurements of ultrahigh magnetic fields produced during intense ( approximately 10(20) Wcm(-2) micro m(2) ) laser interaction experiments with solids. show that polarization high-order vuv harmonics generated the (up to 15th order) suggest existence field strengths 0.7+/-0.1 GG in overdense plasma. Measurements using higher order indicate denser regions plasma can be probed. This technique may useful for multi- level which are predicted occur at even intensities.
The Vulcan Nd : glass laser at the Central Laser Facility is a Petawatt (1015 W) interaction facility available to UK and international user community. came online users in 2002 considerable experience has been gained operating this mode. designed deliver irradiance on target of 1021 W cm−2 for wide-ranging experimental programme fundamental physics advanced applications. This includes super-high-intensity light with matter, fast ignition fusion research, photon induced nuclear reactions,...
The properties of four-wave interaction via the nonlinear quantum vacuum is investigated. effect to generate photons with new frequencies and wave vectors, due elastic photon-photon scattering. An expression for number generated derived using state-of-the-art laser data it found that can reach detectable levels. In particular, prospect high repetition Astra Gemini system at Rutherford Appleton Laboratory discussed. problem noise sources reviewed, level be reduced well below signal level....
Protons accelerated by a picosecond laser pulse have been used to radiograph 500 microm diameter capsule, imploded with 300 J of light in 6 symmetrically incident beams wavelength 1.054 and length 1 ns. Point projection proton backlighting was characterize the density gradients at discrete times through implosion. Asymmetries were diagnosed both during early stagnation stages Comparison analytic scattering theory simple Monte Carlo simulations consistent 3+/-1 g/cm3 core 85+/-10 microm....
The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment CERN the world׳s first experiment. AWAKE will be installed in former CNGS facility uses 400 GeV/c beam bunches from SPS. experiments focus on self-modulation instability of long (rms ~12 cm) bunch plasma. These are planned for end 2016. Later, 2017/2018, low energy (~15 MeV)...
Abstract Presented is a novel way to combine snapshot compressive imaging and lateral shearing interferometry in order capture the spatio-spectral phase of an ultrashort laser pulse single shot. A deep unrolling algorithm utilized for reconstruction due its parameter efficiency superior speed relative other methods, potentially allowing online reconstruction. The algorithm’s regularization term represented using neural network with 3D convolutional layers exploit correlations that exist...
Measurements of energetic proton production resulting from the interaction high-intensity laser pulses with foil targets are described. Through use layered and heating target material we able to distinguish three distinct populations protons. One high energy population is associated a source near front surface observed be emitted characteristic ring structure. A typically lower energy, divergence protons originates rear target. Finally, qualitatively separate even ions large divergence....
Amplification of spontaneous emission (ASE) at 23.6 nm has been studied in a Ge plasma heated by 1 TW infrared laser pulse. The exponent the axial gain reached 21 geometry with Fresnel number \ensuremath{\le}1. Two columns combined length up to 36 mm were used an extreme ultraviolet mirror giving double-pass amplification. Saturation ASE output was observed. beam divergence about 8\ifmmode\times\else\texttimes\fi{} diffraction limited brightness estimated ${10}^{14}$ W...
Neutron production from picosecond laser irradiation of deuterated targets at intensities , P A Norreys, Fews, F N Beg, R Bell, E Dangor, Lee, M B Nelson, H Schmidt, Tatarakis, D Cable
We report on shadowgraphic measurements showing the first space- and time-resolved snapshots of ultraintense laser pulse-generated fast electrons propagating through a solid target. A remarkable result is formation highly collimated jets ( $<20\ensuremath{-}\ensuremath{\mu}\mathrm{m}$) traveling at velocity light extending up to 1 mm. This feature clearly indicates magnetically assisted regime electron transport, critical interest for ignitor scheme. Along with these jets, we detect...