954 research outputs found
Radiation reaction force induced nonlinear mixing of Raman sidebands of an ultra-intense laser pulse in a plasma
Stimulated Raman scattering of an ultra-intense laser pulse in plasmas is
studied by perturbatively including the leading order term of the
Landau-Lifshitz radiation reaction force in the equation of motion for plasma
electrons. In this approximation, radiation reaction force causes phase shift
in nonlinear current densities that drive the two Raman sidebands (anti-Stokes
and Stokes waves), manifesting itself into the nonlinear mixing of two
sidebands. This mixing results in a strong enhancement in the growth of the
forward Raman scattering instability
Nuclear-size self-energy and vacuum-polarization corrections to the bound-electron g factor
The finite nuclear-size effect on the leading bound-electron g factor and the
one-loop QED corrections to the bound-electron g factor is investigated for the
ground state of hydrogen-like ions. The calculation is performed to all orders
in the nuclear binding strength parameter Z\alpha\ (where Z is the nuclear
charge and \alpha\ is the fine structure constant) and for the Fermi model of
the nuclear charge distribution. In the result, theoretical predictions for the
isotope shift of the 1s bound-electron g factor are obtained, which can be used
for the determination of the difference of nuclear charge radii from
experimental values of the bound-electron g factors for different isotopes
Positronium in intense laser fields
The dynamics and radiation of positronium is investigated in intense laser
fields.Comment: 13 pages, 3 figure
Robust signatures of quantum radiation reaction in focused ultrashort laser pulses
Radiation reaction effects in the interaction of an electron bunch with a
superstrong focused ultrashort laser pulse are investigated in the quantum
radiation dominated regime. The angle-resolved Compton scattering spectra are
calculated in laser pulses of variable duration using a semi-classical
description for the radiation dominated dynamics and a full quantum treatment
for the emitted radiation. In dependence of the laser pulse duration we find
signatures of quantum radiation reaction in the radiation spectra, which are
characteristic for the focused laser beam and visible in the qualitative
behaviour of both the angular spread and the spectral bandwidth of the
radiation spectra. The signatures are robust with respect to the variation of
the electron and laser beam parameters in a large range. They fully differ
qualitatively from those in the classical radiation reaction regime and are
measurable with presently available laser technology
Streaking At High Energies With Electrons And Positrons
State-of-the-art attosecond metrology deals with the detection and
characterization of photon pulses with typical energies up to the hundreds of
eV and time resolution of several tens of attoseconds. Such short pulses are
used for example to control the motion of electrons on the atomic scale or to
measure inner-shell atomic dynamics. The next challenge of time-resolving the
inner-nuclear dynamics, transient meson states and resonances requires photon
pulses below attosecond duration and with energies exceeding the MeV scale.
Here we discuss a detection scheme for time-resolving high-energy gamma ray
pulses down to the zeptosecond timescale. The scheme is based on the concept of
attosecond streak imaging, but instead of conversion of photons into electrons
in a nonlinear medium, the high-energy process of electron-positron pair
creation is utilized. These pairs are produced in vacuum through the collision
of a test pulse to be characterized with an intense laser pulse, and they
acquire additional energy and momentum depending on their phase in the
streaking pulse at the moment of production. A coincidence measurement of the
electron and positron momenta after the interaction provides information on the
pair production phase within the streaking pulse. We examine the limitations
imposed by quantum radiation reaction in multiphoton Compton scattering on this
detection scheme, and discuss other necessary conditions to render the scheme
feasible in the upcoming Extreme Light Infrastructure (ELI) laser facility.Comment: 6 pages, 2 figures, contribution to the AIP proceedings of "Light at
Extreme Intensities" (LEI 2011), Szeged, Hungary, Nov 14-18, 201
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