Fully Kinetic Modeling of Dense Plasma Foci From Kilo- to Mega-Amp Devices

Dense plasma focus (DPF) devices use co-axial electrodes to drive kA to MA of current through a Z-pinch plasma implosion. As the plasma implodes, kinetic instabilities [1] in the pinch create MV/cm electric fields that accelerate particles to high-energy (>100 keV). By using deuterium or tritium as a fill gas, a short (few ns), high-intensity neutron source is generated. The goal of our group a LLNL is to simulate and understand the core physics of these devices so that we can optimize them for a variety of applications. For instance, some devices are constrained based on their size and power usage, e.g., to fit into an oil-logging well, while still producing a sizeable neutron yield. Other devices must to be optimized to produce the highest possible neutron yield (up to 10
¹⁴
per pulse) when power constraints are of little concern. In order to meet such requirements, we investigate a variety of techniques using high-fidelity simulations with the kinetic code LSP: – Shaping the interior anode in a way to promote instability growth and reduce asymmetries. – Adding a periodic gas jet to increase the neutron yield and reliability of ion acceleration. – Increasing the density of the fill gas to produce a higherdensity pinch, thus creating a better “target” for the accelerated ions. – Reversing the electrode polarity to investigate its role in electric field generation and subsequent ion generation.