Simulations for Fast Ignition Studies

The historic breakeven laser fusion milestone reached at the NIF in December 2022, and subsequent shots that produced more fusion energy out than laser energy into the target, indicates that laser fusion could be a viable a route to fusion energy. While this method (indirect drive) is currently being considered as an engine for an IFE plant, it is prudent to explore other options. One promising method of achieving high gain is to consider separating the compression and ignition stages in the method. Fast Ignition accomplishes this by using a short pulse laser to create an intense burst of electrons to ignite a pre-compressed DT target. Another approach, based on protons (or ions in general) produced using the TNSA method of energetic proton production, has received considerably less attention. We present select results from a combined theoretical/simulation and experimental program that is revisiting the physics underpinning both of these methods of laser-based fusion in light of recent developments in the field. Specifically, PIC simulations of proton generation¹ and hybrid simulations of resistive magnetic field generation will be discussed.

¹A. J. Kemp, S. C. Wilks, M. Tabak, “Laser-to-proton conversion efficiency studies for proton fast ignition,” Phys. Plasmas 31, 042709 (2024)