22 research outputs found
Thomson scattering in high-intensity chirped laser pulses
We consider the Thomson scattering of an electron in an ultra-intense chirped
laser pulse. It is found that the introduction of a negative chirp means the
electron enters a high frequency region of the field while it still has a large
proportion of its original energy. This results in a significant enhancement of
the energy and intensity of the emitted radiation as compared to the case
without chirping.Comment: 6 pages, 6 figure
Proton acceleration by circularly polarized traveling electromagnetic wave
The acceleration of charged particles, producing collimated mono-energetic
beams, over short distances holds the promise to offer new tools in medicine
and diagnostics. Here, we consider a possible mechanism for accelerating
protons to high energies by using a phase-modulated circularly polarized
electromagnetic wave propagating along a constant magnetic field. It is
observed that a plane wave with dimensionless amplitude of 0.1 is capable to
accelerate a 1 KeV proton to 386 MeV under optimum conditions. Finally we
discuss possible limitations of the acceleration scheme.Comment: 6 pages, 9 figure
Wakefield generation in magnetized plasmas
We consider wakefield generation in plasmas by electromagnetic pulses
propagating perpendicular to a strong magnetic field, in the regime where the
electron cyclotron frequency is equal to or larger than the plasma frequency.
PIC-simulations reveal that for moderate magnetic field strengths previous
results are re-produced, and the wakefield wavenumber spectrum has a clear peak
at the inverse skin depth. However, when the cyclotron frequency is
significantly larger than the plasma frequency, the wakefield spectrum becomes
broad-band, and simultaneously the loss rate of the driving pulse is much
enhanced. A set of equations for the scalar and vector potentials reproducing
these results are derived, using only the assumption of a weakly nonlinear
interaction.Comment: 6 pages, 8 figure
Magnetic mirror cavities as THz radiation sources and a means of quantifying radiation friction
We propose a radiation source based on a magnetic mirror cavity. Relativistic
electrons are simulated entering the cavity and their trajectories and
resulting emission spectra are calculated. The uniformity of the particle
orbits is found to result in a frequency comb in terahertz range, the precise
energies of which are tuneable by varying the electron's -factor. For
very high energy particles radiation friction causes the spectral harmonics to
broaden and we suggest this as a possible way to verify competing classical
equations of motion.Comment: 8 pages, 10 figure
Complete characterization of ultra-intense laser pulses in radiation damping regime
We report the first closed, analytical expression for the scattering angle of
an electron bunch ponderomotively scattered from a counter-propagating,
ultra-intense laser pulse, also accounting for radiation reaction (RR). The
found formulation depends nontrivially on the laser intensity, pulse duration,
beam waist, and energy of the electron bunch. For various laser and bunch
parameters the proposed formula is in excellent quantitative agreement with
full, relativistic test particle simulations in a realistic electromagnetic
field configuration of a focused laser pulse. We also demonstrate how in the
radiation dominated regime a simple rescaling of our model's input parameters
yields excellent quantitative agreement with numerical simulations based on the
Landau-Lifshitz model. Finally, we discuss how the model can be applied for an
in-situ characterization of current and future ultra-high power laser systems,
but also to experimentally probe fundamental properties of RR during
ultra-intense laser electron interaction.Comment: 6 pages, 3 figure