Radiation pressure acceleration: The factors limiting maximum attainable ion energy
- 15 April 2016
- journal article
- research article
- Published by AIP Publishing in Physics of Plasmas
- Vol. 23 (5), 056703
- https://doi.org/10.1063/1.4946025
Abstract
Radiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven ion acceleration, with near complete transfer of the laser energy to the ions in the relativistic regime. However, there is a fundamental limit on the maximum attainable ion energy, which is determined by the group velocity of the laser. The tightly focused laser pulses have group velocities smaller than the vacuum light speed, and, since they offer the high intensity needed for the RPA regime, it is plausible that group velocity effects would manifest themselves in the experiments involving tightly focused pulses and thin foils. However, in this case, finite spot size effects are important, and another limiting factor, the transverse expansion of the target, may dominate over the group velocity effect. As the laser pulse diffracts after passing the focus, the target expands accordingly due to the transverse intensity profile of the laser. Due to this expansion, the areal density of the target decreases, making it transparent for radiation and effectively terminating the acceleration. The off-normal incidence of the laser on the target, due either to the experimental setup, or to the deformation of the target, will also lead to establishing a limit on maximum ion energy.Keywords
Funding Information
- ELI Beamlines (CZ.1.05/1.1.00/02.0061)
- U.S. Department of Energy (DE-AC02-05CH11231)
This publication has 93 references indexed in Scilit:
- Radiation reaction effects on radiation pressure accelerationNew Journal of Physics, 2010
- Generation of GeV protons from 1 PW laser interaction with near critical density targetsPhysics of Plasmas, 2010
- Laser acceleration of low emittance, high energy ions and applicationsComptes Rendus Physique, 2009
- Relativistic Buneman instability in the laser breakout afterburnerPhysics of Plasmas, 2007
- Comment on “Collimated Multi-MeV Ion Beams from High-Intensity Laser Interactions with Underdense Plasma”Physical Review Letters, 2007
- Coulomb explosion effect and the maximum energy of protons accelerated by high-power lasersPhysical Review E, 2005
- Fundamental issues in fast ignition physics: from relativistic electron generation to proton driven ignitionNuclear Fusion, 2003
- Feasibility of using laser ion accelerators in proton therapyPlasma Physics Reports, 2002
- Efficiency of ion acceleration by a relativistically strong laser pulse in an underdense plasmaPlasma Physics Reports, 2001
- Interstellar Vehicle Propelled By Terrestrial Laser BeamNature, 1966