Influence of laser irradiated spot size on energetic electron injection and proton acceleration in foil targets
Publikation/Tidskrift/Serie: Applied Physics Letters
Förlag: American Institute of Physics
Övrig information: Copyright (2012) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
The influence of irradiated spot size on laser energy coupling to electrons, and subsequently to protons, in the interaction of intense laser pulses with foil targets is investigated experimentally. Proton acceleration is characterized for laser intensities ranging from 2 x 10(18) - 6 x 10(20) W/cm(2), by (1) variation of the laser energy for a fixed irradiated spot size, and (2) by variation of the spot size for a fixed energy. At a given laser pulse intensity, the maximum proton energy is higher under defocus illumination compared to tight focus and the results are explained in terms of geometrical changes to the hot electron injection. (C) 2012 American Institute of Physics. doi:10.1063/1.3685615
- Physics and Astronomy
- ISSN: 0003-6951