The Mégajoule Laser (LMJ) is a large-scale research instrument designed to heat and compress matter to conditions similar to those found in nuclear weapon operation or at the core of stars. The LMJ (a nanosecond-scale megajoule-class laser) is primarily used for defense applications, supporting the safety and reliability guarantee of France's nuclear deterrent. Since its coupling with the high-power PETAL laser (a picosecond-scale kilojoule-class laser), the LMJ has also been made available to the international scientific community for academic research. Experiments conducted with these two lasers can generate extremely high electromagnetic fields, potentially causing malfunctions in the facility's equipment.
This post-doctoral position is part of a collaboration between teams from CEA/CESTA and CELIA (a joint research unit of the University of Bordeaux, CNRS, and CEA), as well as other European laboratories.
A 3D multi-scale simulation chain has been developed to assess the amplitude, duration, and spectral content of the Electromagnetic Pulse (EMP). To mitigate EMP intensity, a new target holder (EMP mitigation device) has been designed. The electromagnetic environment of the facility is also monitored using specialized diagnostics, including a new device for measuring target discharge current.
The ongoing PETAL Upgrade project aims to enhance PETAL's performance. Additionally, the final LMJ laser chains are currently being commissioned, and the total laser energy will significantly increase in the coming years. Furthermore, new laser target technologies will soon be tested. These developments are likely to increase EMP levels on the facility. Therefore, a precise evaluation of this increase and improved reliability of the EMP mitigation device are essential.