Related papers: Particle Acceleration in Shearing Flows: Efficienc…
Spectrally-peaked proton beams ($E_{p}\approx 8$ MeV, $\Delta E\approx 4$ MeV) have been observed from the interaction of an intense laser ($> 10^{19 }$ Wcm$^{-2}$) with ultrathin CH foils, as measured by spectrally-resolved full beam…
The production of energetic (multi-GeV) heavy ion beams by acceleration of ultra-thin foils through the application of radiation pressure to a self-generated, imperfect plasma mirror (photon absorption probability {\eta} finite) is studied.…
Recent discovery of fast blue optical transients (FBOTs) as a new class of energetic transient sources can shed light on the long-standing problem of supernova-long gamma-ray burst connections. A distinctive feature of such objects is the…
We consider particle acceleration by large-scale incompressible turbulence with a lengthscale larger than the particle mean free path. We derive an ensemble-averaged transport equation of energetic charged particles from an extended…
A mechanism for proton acceleration to ~10^21eV is suggested. It may operate in accretion flows onto thin dark matter filaments of cosmic structure formation. The flow compresses the ambient magnetic field to strongly increase and align it…
The linear theory of shock acceleration predicts the maximum particle energy to be limited only by the acceleration time and the size of the shock. We study the combined effect of acceleration nonlinearity (shock modification by accelerated…
We study motion of a relativistic charged particle in a plane slow electromagnetic wave and background uniform magnetic field. The wave propagates normally to the background field. Under certain conditions, the resonance between the wave…
We present a model for the relative velocity of inertial particles in turbulent flows. Our general formulation shows that the relative velocity has contributions from two terms, referred to as the generalized acceleration and generalized…
The motion of fluid particles as they are pushed along erratic trajectories by fluctuating pressure gradients is fundamental to transport and mixing in turbulence. It is essential in cloud formation and atmospheric transport, processes in…
Laser-plasma accelerators offer a compact means of producing high-energy electron beams, but their performance is fundamentally limited by dephasing between the accelerated electrons and the plasma wave. To overcome this limitation, we…
Proton acceleration by using a 620-TW, 18-J laser pulse of peak intensity of $5\times 10^{21}$ W/cm$^{2}$ irradiating a disk target is examined using three-dimensional particle-in-cell simulations. It is shown that protons are accelerated…
An experimental study of laser driven electron acceleration in N2 and N2-He mixed gas-jet target using laser pulses of duration ~60-70 fs is presented. Generation of relativistic electron beam with quasi-thermal spectra was observed at a…
Accelerating particles to high energies in plasma wakefields is considered to be a promising technique with good energy efficiency and high gradient. While important progress has been made in plasma-based electron acceleration, positron…
A particle acceleration mechanism by radiation pressure of precursor waves in a relativistic shock is studied. For a relativistic, perpendicular shock with the upstream bulk Lorentz factor of $\gamma_1 \gg 1$, large amplitude…
Using a kilojoule class laser, we demonstrate for the first time that high-contrast picosecond pulses are advantageous for ion acceleration. We show that a laser pulse with optimum duration and a large focal spot accelerates electrons…
Supernova remnants (SNRs) are thought to be the most promising sources of Galactic cosmic rays. One of the principal questions is whether they are accelerating particles up to the maximum energy of Galactic cosmic rays ($\sim$ PeV). In this…
To reach the flyer plate velocities in excess of 1000km/sec required for impact ignition, it is proposed to combine the ablation acceleration of a dense hydrogen jet by its isentropic compression in a convergent Prandtl-Meyer flow,…
Autoresonance laser acceleration of electrons is theoretically investigated using circularly polarized focused Gaussian pulses. Many-particle simulations demonstrate feasibility of creating over 10-GeV electron bunches of ultra-high quality…
Astrophysical sources are extremely efficient accelerators. Some sources emit photons up to multi-TeV energies, a signature of the presence, within them, of particles with energies much higher than those achievable with the largest…
We report on systematic and high-precision measurements of dephasing, an effect that fundamentally limits the performance of laser wakefield accelerators. Utilizing shock-front injection, a technique providing stable, tunable and…