Simple few-shot method for spectrally resolving the wavefront of an ultrashort laser pulse.

We present a novel, to the best of our knowledge, and straightforward approach for the spatio-spectral characterization of ultrashort pulses. This minimally intrusive method relies on placing a mask with specially arranged pinholes in the beam path before the focusing optic and retrieving the spectrally resolved laser wavefront from the speckle pattern produced at focus. We test the efficacy of this new method by accurately retrieving chromatic aberrations, such as pulse-front tilt (PFT), pulse-front curvature (PFC), and higher-order aberrations introduced by a spherical lens.

High Average Gradient in a Laser-Gated Multistage Plasma Wakefield Accelerator.

Plasma wakefield accelerators driven by particle beams are capable of providing accelerating gradient several orders of magnitude higher than currently used radio-frequency technology, which could reduce the length of particle accelerators, with drastic influence on the development of future colliders at TeV energies and the minimization of x-ray free-electron lasers. Since interplasma components and distances are among the biggest contributors to the total accelerator length, the design of staged plasma accelerators is one of the most important outstanding questions in order to render this technology instrumental. Here, we present a novel concept to optimize interplasma distances in a staged beam-driven plasma accelerator by drive-beam coupling in the temporal domain and gating the accelerator via a femtosecond ionization laser.

Controlled acceleration of GeV electron beams in an all-optical plasma waveguide.

Laser-plasma accelerators (LPAs) produce electric fields of the order of 100 GV m, more than 1000 times larger than those produced by radio-frequency accelerators. These uniquely strong fields make LPAs a promising path to generate electron beams beyond the TeV, an important goal in high-energy physics. Yet, large electric fields are of little benefit if they are not maintained over a long distance.

Bright synchrotron radiation from relativistic self-trapping of a short laser pulse in near-critical density plasma.

In a dense gas plasma a short laser pulse propagates in a relativistic self-trapping mode, which enables the effective conversion of laser energy to the accelerated electrons. This regime sustains effective loading which maximizes the total charge of the accelerating electrons, that provides a large amount of betatron radiation. The three-dimensional particle-in-cell simulations demonstrate how such a regime triggers x-ray generation with 0.

Symmetric and asymmetric shocked gas jets for laser-plasma experiments.

Shocks in supersonic flows offer both high density and sharp density gradients that are used, for instance, for gradient injection in laser-plasma accelerators. We report on a parametric study of oblique shocks created by inserting a straight axisymmetric section at the end of a supersonic "de Laval" nozzle. The effect of different parameters, such as the throat diameter and straight section length on the shock position and density, is studied through computational fluid dynamics (CFD) simulations.