arXiv subjects

C. D. Murphy

Publications and source records attributed to C. D. Murphy.

20 records · Page 2Linked to original sources

arXiv2008

Resonant Plasma Wave Growth and Monoenergetic Electron Beam Production using Collinear High-Intensity Ultrashort Laser Pulses

The resonant generation of relativistic plasma waves and plasma wave guiding by two co-propagating laser pulses has been studied. By proper timing between guiding and driver pulses, a resonant interaction occurs, which generates a high-amplitude plasma wave over a longer length than is possible with either of the laser pulses individually. The growth of the plasma wave is inferred by the measurement of monoenergetic electron beams with low divergence that are not measured by using either of the pulses individually. This scheme can be easily implemented, and allows more control of the interaction than is available to the single pulse scheme.

physics.plasm-ph↗

arXiv2007

The Effect of Laser Focusing Conditions on Propagation and Monoenergetic Electron Production in Laser Wakefield Accelerators

The effect of laser focusing conditions on the evolution of relativistic plasma waves in laser wakefield accelerators is studied both experimentally and with particle-in-cell simulations. For short focal length ($w_0 < λ_p$) interactions, beam break-up prevents stable propagation of the pulse. High field gradients lead to non-localized phase injection of electrons, and thus broad energy spread beams. However for long focal length geometries ($w_0 > λ_p$), a single optical filament can capture the majority of the laser energy, and self-guide over distances comparable to the dephasing length, even for these short-pulses ($cτ\approx λ_p$). This allows the wakefield to evolve to the correct shape for the production of the monoenergetic electron bunches, as measured in the experiment.

physics.plasm-ph↗