Increased laser-accelerated proton energies via direct laser-light-pressure acceleration of electrons in microcone targets
- Helmholtz-Zentrum Dresden Rossendorf, Institut fuer Strahlenphysik, PF 51 01 19, Dresden, 01314 (Germany)
- Los Alamos National Laboratory, P-24, P.O. Box 1663, MS E526, Los Alamos, New Mexico 87545 (United States)
- Electrical and Computer Engineering Department, University of Missouri-Columbia, 227 Engineering Building West, Columbia, Missouri 65211 (United States)
- Department of Physics, University of Nevada, Reno, MS 220, 1664 North Virginia St., Reno, Nevada 89557 (United States)
- Sandia National Laboratories, P.O. Box 5800, MS 1193, Albuquerque, New Mexico 87185 (United States)
We present experimental results showing a laser-accelerated proton beam maximum energy cutoff of 67.5 MeV, with more than 5 x 10{sup 6} protons per MeV at that energy, using flat-top hollow microcone targets. This result was obtained with a modest laser energy of {approx}80 J, on the high-contrast Trident laser at Los Alamos National Laboratory. From 2D particle-in-cell simulations, we attribute the source of these enhanced proton energies to direct laser-light-pressure acceleration of electrons along the inner cone wall surface, where the laser light wave accelerates electrons just outside the surface critical density, in a potential well created by a shift of the electrostatic field maximum with respect to that of the magnetic field maximum. Simulations show that for an increasing acceleration length, the continuous loading of electrons into the accelerating phase of the laser field yields an increase in high-energy electrons.
- OSTI ID:
- 21537908
- Journal Information:
- Physics of Plasmas, Vol. 18, Issue 5; Other Information: DOI: 10.1063/1.3575624; (c) 2011 American Institute of Physics; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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