Ablation of Nonlinear-Force Driven Plasma Blocks for Fast Igniter Application

摘要

Interaction of TW-ps laser with plasma results in a skin layer mechanism for nonlinear (ponderomotive) force driven two dimensional plasma blocks (pistons) if a very high contrast ratio is provided for suppression of relativistic self-focusing. This Skin layer acceleration (SLA) results in space charge neutral plasma blocks with ion current densities larger than 10~(10) Amp/cm~2. Using Ions in the MeV range results in 1000 times higher proton or DT current densities than the proton fast igniter is using and may result in better conditions of this fast ignitor scheme. Using ballistic focusing of the generated plasma blocks and a short time thermal expansion of these blocks for increasing their thickness while keeping the high ion current densities, results in conditions favourable for this option of fast ignition of a fusion target. Some details of the interaction processes are still to be analysed but the solutions studies to date are most encouraging.