Related papers: Compton Scattering, Pair Annihilation and Pair Pro…
Gamma-ray beams with large angular momentum are a very valuable tool to study astrophysical phenomena in a laboratory. We investigate generation of well-collimated $\gamma$-ray beams with a very large orbital angular momentum using…
We present the results of a new experimental study of the quantum entanglement of photon pairs produced in positron-electron annihilation at rest. The experimental setup includes a system of Compton polarimeters to measure the Compton…
We describe electron-positron pairs creation around an electrically charged star core collapsing to an electromagnetic black hole (EMBH), as well as pairs annihilation into photons. We use the kinetic Vlasov equation formalism for the pairs…
Electrons at the surface of a plasma that is irradiated by a laser with intensity in excess of $10^{23}~\mathrm{W}\mathrm{cm}^{-2}$ are accelerated so strongly that they emit bursts of synchrotron radiation. Although the combination of high…
We develop a field-theoretic model for the description of proton Compton scattering in which the proton and its excited state, the \Delta+ resonance, are described as part of one multiplet with a single Rarita-Schwinger wavefunction. In…
The process of electron-positron annihilation into two photons in the presence of an intense classical plane wave of an arbitrary shape is investigated analytically by employing light-cone quantization and by taking into account the effects…
We study the emission and absorption spectra due to various photon and pair processes in a non-equilibrium pair plasma containing a significant density of photons. We present here some preliminary results from Monte-Carlo simulations. These…
We present results for the photon spectrum emitted in non-linear Compton scattering of pulsed ultra-strong laser fields off relativistic electrons for intensities up to $a_0\gtrsim 100$ and pulse lengths of a few laser cycles. At ultrahigh…
The accumulation of electrons and positrons in the vacuum magnetosphere of a neutron star with a surface magnetic field of B~10^12 G is considered. It is shown that particles created in the magnetosphere or falling into the magnetosphere…
We calculate photon production from a quark-gluon plasma which is anisotropic in momentum space including the Compton scattering and quark/anti-quark annihilation processes. We show that for a quark-gluon plasma which has an oblate…
We present a new concept of nonlinear dynamics of incoherent superstrong radiation in plasmas. Recently we have disclosed a novel mechanism of the establishment of equilibrium between a photon and a dense photon bunch through the exchange…
The Kompaneets theory of photon kinetic evolution due to the Compton effect is extended to the case of the Vlasov plasma wave oscillations. Taking into account Zel'dovich-Levich's approximation we study interaction of accumulating photons…
We determine the spectrum of particles accelerated at shocks with arbitrary speed and arbitrary scattering properties for different choices of the equation of state of the downstream plasma. More specifically we consider the effect of…
We have searched for stimulated photon scattering in vacuum at a center of mass photon energy of 0.8 eV. The QED contribution to this process is equivalent to four wave mixing in vacuum. No evidence for gamma-gamma scattering was observed.…
We calculate the Thomson scattering cross section in a non-relativistic, magnetized, high density plasma -- in a regime where collective excitations can be described by magnetohydrodynamics. We show that, in addition to cyclotron resonances…
A new process associated with the nonlinear optical properties of the electromagnetic vacuum, as predicted by quantum electrodynamics, is described. This can be called photon acceleration in vacuum, and corresponds to the frequency shift…
We study the $2\rightarrow1$ process of electron-positron pair annihilation to a single photon in a plane-wave background. The probability of the process in a pulsed plane wave is presented, and a locally constant field approximation is…
A relativistic pair-plasma which contains a high excitation of electrostatic turbulence could produce intense radiation at brightness temperature in excess of 10^22 K by stimulated scattering. Important relativistic effects would include…
We study processes at the transition region between hot (rare) and cold (dense) plasma in the collisionless regime. We use a 3-dimensional electromagnetic particle-in-cell (3-D PIC) relativistic code. Motivated by the transition region in…
Photons preferentially Compton scatter perpendicular to the plane of polarisation. This property can be exploited to design instruments to measure the linear polarisation of hard X-rays ($\sim$10 - 100 keV). Photons may undergo two…