A5082760513- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- High-pressure geophysics and materials
- Laser-Matter Interactions and Applications
- Nuclear Physics and Applications
- Ion-surface interactions and analysis
- Radiation Therapy and Dosimetry
- Atomic and Molecular Physics
- Laser Design and Applications
- Particle accelerators and beam dynamics
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Magnetic confinement fusion research
- Advanced X-ray Imaging Techniques
- Diamond and Carbon-based Materials Research
- Atomic and Subatomic Physics Research
- Particle Accelerators and Free-Electron Lasers
- Advanced Radiotherapy Techniques
- Laser Material Processing Techniques
- Solar and Space Plasma Dynamics
- Solid State Laser Technologies
- Planetary Science and Exploration
- Radioactivity and Radon Measurements
- Plasma Diagnostics and Applications
- Spacecraft and Cryogenic Technologies
Queen's University Belfast
2016-2025
Community Hospital
2015-2024
Women and Children’s Health Research Institute
2022
Rutherford Appleton Laboratory
2009-2021
University of California, Los Angeles
2021
Université de Bordeaux
2019
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2019
Centre Lasers Intenses et Applications
2019
Centre National de la Recherche Scientifique
2019
Czech Academy of Sciences, Institute of Plasma Physics
2017
A new regime is described for radiation pressure acceleration of a thin foil by an intense laser beam above 1020 W cm−2. Highly monoenergetic proton beams extending to giga-electron-volt energies can be produced with very high efficiency using circularly polarized light. The have small divergence angle (<4°). This method allows the construction ultra-compact and ion accelerators ultra-short particle bursts.
The range of potential applications compact laser-plasma ion sources motivates the development new acceleration schemes to increase achievable energies and conversion efficiencies. Whilst evolving nature interactions can limit effectiveness individual mechanisms, it also enable hybrid schemes, allowing additional degrees control on properties resulting beam. Here we report an experimental demonstration efficient proton exceeding 94 MeV via a scheme radiation pressure-sheath in ultrathin foil...
Abstract Electron–positron pair plasmas represent a unique state of matter, whereby there exists an intrinsic and complete symmetry between negatively charged (matter) positively (antimatter) particles. These play fundamental role in the dynamics ultra-massive astrophysical objects are believed to be associated with emission ultra-bright gamma-ray bursts. Despite extensive theoretical modelling, our knowledge this matter is still speculative, owing extreme difficulty recreating neutral...
The acceleration of ions from ultrathin foils has been investigated by using 250 TW, subpicosecond laser pulses, focused to intensities up $3\ifmmode\times\else\texttimes\fi{}{10}^{20}\text{ }\text{ }\mathrm{W}\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$. ion spectra show the appearance narrow-band features for protons and carbon peaked at higher energies (in $5--10\text{ }\mathrm{MeV}/\mathrm{\text{nucleon range}}$) with significantly flux than previously reported. spectral their scaling target...
A study of the properties multi-MeV proton emission from thin foils following ultraintense laser irradiation has been carried out. It shown that protons are emitted, in a quasilaminar fashion, region transverse size order 100-200 microm. The imaging source equivalent to those much smaller located several hundred microm front foil. This finding obtained by analyzing radiographs periodically structured test objects, and is corroborated observations laser-heated thick targets.
The acceleration of multi-MeV protons from the rear surface thin solid foils irradiated by an intense (approximately 10(18) W/cm2) and short 1.5 ps) laser pulse has been investigated using transverse proton probing. structure electric field driving expansion beam resolved with high spatial temporal resolution. main features experimental observations, namely, initial sheath a late time peaking at front, are consistent results particle-in-cell fluid simulations plasma into vacuum.
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...
Plasma mirrors are devices capable of switching very high laser powers on subpicosecond time scales with a dynamic range 20–30 dB. A detailed study their performance in the near-field beam is presented, setup relevant to improving pulse contrast modern ultrahigh power lasers (TW–PW). The conditions under which reflectivity can be achieved and focusability reflected retained identified. At higher intensities region specular rapidly decreasing was observed, suggesting that alone not an...
The problem of the 'hole-boring' (HB)-type radiation pressure acceleration ions by circularly polarized laser pulses interacting with overdense plasmas is considered in regime where dimensionless scaling parameter I/ρc3 becomes large. In this a non-relativistic treatment 'HB' no longer adequate. A new set fully relativistic formulae for mean ion energy and velocity derived validated against one-dimensional particle-in-cell simulations. It also found that finite time results large spreads...
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....
Abstract All-optical approaches to particle acceleration are currently attracting a significant research effort internationally. Although characterized by exceptional transverse and longitudinal emittance, laser-driven ion beams have limitations in terms of peak energy, bandwidth the energy spectrum beam divergence. Here we introduce concept versatile, miniature linear accelerating module, which, employing laser-excited electromagnetic pulses directed along helical path surrounding...
Pulsed beams of energetic x-rays and neutrons from intense laser interactions with solid foils are promising for applications where bright, small emission area sources, capable multi-modal delivery ideal. Possible end users laser-driven sources those requiring advanced non-destructive inspection techniques in industry sectors high value commerce such as aerospace, nuclear manufacturing. We report on experimental work that demonstrates operation power laser-solid neutron x-ray beam...
The ultrashort duration of laser-driven multi-MeV ion bursts offers the possibility radiobiological studies at extremely high dose rates. Employing TARANIS Terawatt laser Queen's University, effect proton irradiation MeV-range energies on live cells has been investigated rates exceeding 109 Gy/s as a single exposure. A clonogenic assay showed consistent lethal effects V-79 cells, which, even these rates, appear to be in line with previously published results employing conventional sources....
A novel regime is proposed where, by employing linearly polarized laser pulses at intensities 10(21) W cm(-2) (2 orders of magnitude lower than discussed in previous work [T. Esirkepov et al., Phys. Rev. Lett. 92, 175003 (2004)]), ions are dominantly accelerated from ultrathin foils the radiation pressure and have monoenergetic spectra. In this regime, hole-boring process quickly catch up with target normal sheath acceleration, they then join a single bunch, undergoing hybrid...
Novel targets were implemented in the beam-driven (in-target) proton-boron fusion with beneficial characteristics (chemical composition and density) compared to commonly used boron nitride. A fusion-generated alpha particle flux of up <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mo>(</a:mo><a:mrow><a:mn>5</a:mn><a:mo>×</a:mo><a:msup><a:mn>10</a:mn><a:mn>7</a:mn></a:msup></a:mrow><a:mspace...
Laser driven proton beams have been used to diagnose transient fields and density perturbations in laser produced plasmas. Grid deflectometry techniques applied radiography obtain precise measurements of beam angles caused by electromagnetic Application implosions has demonstrated that conditions compressed media can be diagnosed with million electron volt protons. This data shown provide unique insight into super critical plasmas a perturbation diagnostics matter.
In the last few years, high power lasers have demonstrated possibility to explore a new state of matter, so-called warm dense matter. Among possible techniques utilized generate this state, we present dynamic compression technique using lasers. Applications planetary cores material (iron) will be discussed. Finally diagnostics such as proton and hard-x-ray radiography shock propagating in solid target presented.
Guided transport of a relativistic electron beam in solid is achieved experimentally by exploiting the strong magnetic fields created at interface two metals different electrical resistivities. This substantial relevance to Fast Ignitor approach fusion energy production [M. Tabak, Phys. Plasmas 12, 057305 (2005)10.1063/1.1871246], since it allows deposition be spatially tailored-thus adding design flexibility and preventing inefficiencies due spreading. In experiment, optical transition...
Abstract The properties of beams high energy protons accelerated during ultraintense, picosecond laser-irradiation thin foil targets are investigated as a function preplasma expansion at the target front surface. Significant enhancement in maximum proton and laser-to-proton conversion efficiency is observed optimum density gradients, due to self-focusing incident laser pulse. For very long expansion, propagating pulse filament, resulting highly uniform beams, but with reduced flux energy.
We demonstrate experimentally that the relativistic electron flow in a dense plasma can be efficiently confined and guided targets exhibiting high-resistivity-core-low-resistivity-cladding structure analogous to optical waveguides. The beam is shown an area of order core diameter (50 μm), which has potential substantially enhance coupling efficiency electrons compressed fusion fuel Fast Ignitor full-scale experiments.
The dynamics of magnetic fields with an amplitude several tens megagauss, generated at both sides a solid target irradiated high-intensity (~10(19) W/cm(2)) picosecond laser pulse, has been spatially and temporally resolved using proton imaging technique. the is sufficiently large to have constraining effect on radial expansion plasma sheath surfaces. These results, supported by numerical simulations simple analytical modeling, may implications for ion acceleration driven rear side as well...
Highly anisotropic, beam-like neutron emission with peak flux of the order 109 n/sr was obtained from light nuclei reactions in a pitcher–catcher scenario, by employing MeV ions driven sub-petawatt laser. The spatial profile beam, fully captured for first time CR39 nuclear track detector, shows FWHM divergence angle , nearly an magnitude higher than isotropic component elsewhere. observed beamed neutrons is highly favourable wide range applications, and indeed further transport moderation to...
The acceleration of ions from ultrathin (10--100 nm) carbon foils has been investigated using intense ($\ensuremath{\sim}6\ifmmode\times\else\texttimes\fi{}1{0}^{20}\text{ }\mathrm{W}\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$) ultrashort (45 fs) laser pulses, highlighting a strong dependence the ion beam parameters on polarization, with circularly polarized (CP) pulses producing highest energies for both protons and carbons ($25\ensuremath{-}30\text{ }\text{ }\mathrm{MeV}/\mathrm{nucleon}$);...
The main direction proposed by the community of experts in field laser-driven ion acceleration is to improve particle beam features (maximum energy, charge, emittance, divergence, monochromaticity, shot-to-shot stability) order demonstrate reliable and compact approaches be used for multidisciplinary applications, thus, principle, reducing overall cost a laser-based facility compared conventional accelerator one and, at same time, demonstrating innovative more effective sample irradiation...