Longitudinal Ion Acceleration from High-Intensity Laser Interactions with Underdense Plasma
Abstract
Longitudinal ion acceleration from high-intensity (I ~ 10^20 Wcm^-2) laser interactions with helium gas jet targets (n_e ~ 0.04 n_c) have been observed. The ion beam has a maximum energy for He^2+ of approximately 40 MeV and was directional along the laser propagation path, with the highest energy ions being collimated to a cone of less than 10 degrees. 2D particle-in-cell simulations have been used to investigate the acceleration mechanism. The time varying magnetic field associated with the fast electron current provides a contribution to the accelerating electric field as well as providing a collimating field for the ions. A strong correlation between the plasma density and the ion acceleration was found. A short plasma scale-length at the vacuum interface was observed to be beneficial for the maximum ion energies, but the collimation appears to be improved with longer scale-lengths due to enhanced magnetic fields in the ramp acceleration region.
Cite
@article{arxiv.0712.2732,
title = {Longitudinal Ion Acceleration from High-Intensity Laser Interactions with Underdense Plasma},
author = {L. Willingale and S. P. D. Mangles and P. M Nilson and R. J. Clarke and A. E. Dangor and M. C. Kaluza and S. Karsch and K. L. Lancaster and W. B. Mori and J. Schreiber and A. G. R. Thomas and M. S. Wei and K. Krushelnick and Z. Najmudin},
journal= {arXiv preprint arXiv:0712.2732},
year = {2009}
}
Comments
18 pages, 6 figures