Numerical studies of the generation of GeV heavy ions at laser irradiation

Relativistic self-focussing of a laser beam in cut-off dense plasma leads to a fast shrinking of the beam to a diameter of a wavelength. The very high focus intensities should accelerate ions to very high energies by nonlinear (radiation) forces, if counteracting depletion of the plasma is delayed sufficiently. An extensive numerical study uses a very general beam propagation with two-dimensional plasma dynamics including nonlinear forces and nonlinear relativistic optical constants. A 5 psec neodymium glass laser pulse of 10¹³ watts in tin targets generates 38 times ionized ions of 5 GeV energy. Lateral density rippling of 4 wavelength period are explained by Huygens principle.