Plasma channel charging by an intense short pulse laser and ion Coulomb explosion

Abstract

The combined effects of relativistic self-focusing and the expulsion of electrons by the ponderomotive force of a radially focused laser create an ion channel, depleted of electrons, of radius r0∼c∕ωp, where ωp is the electron plasma frequency. This charging process takes place on plasma period, ωp−1, time scale. The Coulomb explosion of the channel accelerates ions to several hundreds of keV energy in about an ion plasma period, constituting an important ion acceleration mechanism by short pulse intense laser. In the case of a deuterium-tritium plasma, the accelerated ions can produce fusion energy with an efficiency of ∼0.5%.