Scientific Coordinator: Dimitri Batani (CELIA, University of Bordeaux)
We aim at realizing a European research program on Shock Ignition (SI), a promising approach to Inertial Fusion, based on the separation of the compression phase of the thermonuclear target from the ignition phase, which is realized by a high-intensity laser beam (up to 1016 W/cm2 in a spike of several hundreds picosecond).
The feasibility of SI relies on the capacity of such spike to produce a very strong converging shock (at least 300 Mbar at the ablation front). Being substantially compatible with present-day laser technology (used to build NIF and LMJ), SI could be tested within the next decade. The beginning of operation of the LMJ/PETAL laser facility and its academic opening to Civilian Research done by European Academic groups opens, for the first time, the possibility of performing inertial fusion experiments at full-scale in Europe.
In order to prepare such future experiments, we will perform experiments in Europe (PALS) and at the laser facility Omega at the University of Rochester, with the goal of both answering some open physical questions related to SI and consolidating a European research community directly working on inertial fusion experiments with big lasers.
The main physical questions, which we want to address, aim 1) at investigating the generation of hot electrons in the intensity regime relevant for SI and their effects on shock generation and dynamics, and at evaluating to what extent hot electrons are an essential ingredient for reaching shock pressures ≥ 300 MBar, and 2) at evaluating the need for uniformity in the laser spike, and the eventually assessing the possibility of realizing a bipolar irradiation of the target (which would be immediately compatible with machines built to realize indirect drive, like NIF and LMJ).
Apart answering these physical questions, the final output of the project will also be the preparation of a proposal for a joint experiment on the bipolar irradiation scheme to be performed on LMJ/PETAL.
