Detail Project and Funding

Abstract: 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

INO’s Experiments/Theoretical Study correlated:
Laser-plasma interaction in a regime relevant for laser-fusion via shock-ignition

The Scientific Results:
1) Time evolution of Stimulated Raman Scattering and Two Plasmon Decay at laser intensities relevant for Shock Ignition in a hot plasma
2) Experimental observation of parametric instabilities at laser intensities relevant for shock ignition
3) Experimental Investigation on parametric instabilities in shock ignition regime at PALS
4) Experimental investigation on parametric instabilities at PALS at intensities relevant to shock ignition
5) Measurements of parametric instabilities at laser intensities relevant to strong shock
generation
6) Experimental investigation on parametric instabilities in a regime relevant for Shock Ignition at PALS
7) Laser plasma interaction experiments
relevant for shock ignition at PALS
8) Progress in understanding the role of hot electrons for the shock ignition approach to inertial confinement fusion
9) Wavelength dependence of laser plasma interaction related to shock ignition approach
10) Time evolution of stimulated Raman scattering and two-plasmon decay at laser intensities relevant for shock ignition in a hot plasma
11) Laser-driven strong shocks with infrared lasers at intensity of 1016 W/cm2