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 $\gamma$-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