Focusing of high-current laser-driven ion beams
- Institute of Plasma Physics and Laser Microfusion, EURATOM Association, Warsaw 00-908 (Poland)
Using a two-dimensional relativistic hydrodynamic code, it is shown that a dense high-current ion beam driven by a short-pulse laser can be effectively focused by curving the target front surface. The focused beam parameters essentially depend on the density gradient scale length of the preplasma L{sub n} and the surface curvature radius R{sub T}. When L{sub n}{<=}0.5{lambda}{sub L} ({lambda}{sub L} is the laser wavelength) and R{sub T} is comparable with the laser beam aperture d{sub L}, a significant fraction of the accelerated ions is focused on a spot much smaller than d{sub L}, which results in a considerable increase in the ion fluence and current density. Using high-contrast multipetawatt picosecond laser pulses of relativistic intensity ({approx}10{sup 20} W/cm{sup 2}), focused ion (proton) current densities approaching those required for fast ignition of DT fuel seem to be feasible.
- OSTI ID:
- 20960204
- Journal Information:
- Applied Physics Letters, Vol. 90, Issue 15; Other Information: DOI: 10.1063/1.2721394; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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