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–Speaker–
Dr. Raspberry Simpson
Lawrence Livermore National Laboratory (LLNL)

–Title–
Scaling Laser-Driven Proton Acceleration to the IFE Regime

–Abstract–
Ion fast ignition is an alternative inertial confinement fusion scheme, which relies on using laser-accelerated ions of MeV energies to heat pre-compressed inertial confinement fusion pellet in order to relax driver energy and symmetry requirements while increasing fuel gain. [1] Petawatt-class, multi-picosecond short-pulse lasers, such as the National Ignition Facility-Advanced Radiographic Capability (NIF-ARC) laser, Orion laser facility and OMEGA-Extended Performance (EP) laser, which have been constructed over the last two decades, enable exciting opportunities to produce high-brightness, high- energy laser-driven ion sources which will be crucial for developing and investigating proton fast ignition platforms for inertial fusion energy. Laser-driven ion sources are typically spatially divergent (divergence angles ~ 20 degrees) therefore mechanisms to focus laser-driven proton sources are a crucial area of research to increase the efficiency of these sources for applications to isochoric heating and ion fast ignition fusion. This work investigates the use of structured targets such as hemispherical shaped foils and cones that can be used to focus the ion source to achieve a higher flux and thus increase focusing efficiency. In particular, we present a series of experiments on the OMEGA-EP, NIF-ARC and Orion laser facilities studying the optimization of ion focusing for application to ion fast ignition in the multi-ps regime.

[1] M. Roth et al. PRL 86 436 (2001)
[2] R.A. Simpson et al. PoP 28 013108 (2021)

This work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract DE AC52 07NA27344 with funding support from the Laboratory Directed Research and Development program under LDRD 23-ER-047. LLNL-ABS-872805