Betatron emission as a diagnostic for injection and acceleration mechanisms in laser-plasma accelerators

Abstract

Betatron x-ray emission in laser-plasma accelerators is a promising compact source that may be an alternative to conventional x-ray sources, based on large scale machines. In addition to its potential as a source, precise measurements of betatron emission can reveal crucial information about relativistic laser-plasma interaction. We show that the emission length and the position of the x-ray emission can be obtained by placing an aperture mask close to the source, and by measuring the beam profile of the betatron x-ray radiation far from the aperture mask. The position of the x-ray emission gives information on plasma wave breaking and hence on the laser non-linear propagation. Moreover, the measurement of the longitudinal extension helps one to determine whether the acceleration is limited by pump depletion or dephasing effects. In the case of multiple injections, it is used to retrieve unambiguously the position in the plasma of each injection. This technique is also used to study how, in a capillary discharge, the variations of the delay between the discharge and the laser pulse affect the interaction. The study reveals that, for a delay appropriate for laser guiding, the x-ray emission only occurs in the second half of the capillary: no electrons are injected and accelerated in the first half.

arXiv comment8 pages, 6 figures. arXiv admin note: text overlap with arXiv:1104.2451

References in corpus (6)

• Generating multi-GeV electron bunches using single stage laser wakefield acceleration in a 3D nonlinear regime
• Single shot phase contrast imaging using laser-produced Betatron x-ray beams
• Demonstration of the synchrotron-type spectrum of laser-produced Betatron radiation
• Controlling the spectrum of x-rays generated in a laser-plasma accelerator by tailoring the laser wavefront
• Controlled Betatron X-Ray Radiation from Tunable Optically Injected Electrons
• Mapping the X-Ray Emission Region in a Laser-Plasma Accelerator

Cited by in corpus (4)

• Characterization and Application of Hard X-Ray Betatron Radiation Generated by Relativistic Electrons from a Laser-Wakefield Accelerator
• High Flux Femtosecond X-ray Emission from the Electron-Hose Instability in Laser Wakefield Accelerators
• Spectrum bandwidth narrowing of Thomson scattering X-rays with energy chirped electron beams from laser wakefield acceleration
• TeV acceleration in a Matryoshka plasma channel