A recent study has utilized particle-in-cell (PIC) simulations with the EPOCH code to investigate the phenomenon of Coulomb explosion in the hotspots of dense plasma focus (DPF) devices. These hotspots are regions of extremely high-density and high-temperature plasma that form during the compression phase of a DPF, and are of great interest for their potential in nuclear fusion production and high-energy radiation sources. Coulomb explosion, a process where highly charged ions repel each other with great force after rapid ionization, has been identified as a key mechanism in the dynamics of these extreme plasmas.

The research focused on understanding how Coulomb explosion contributes to the emission of high-energy ions and the formation of complex structures within the hotspot. The simulations revealed that, under the extreme conditions of DPFs, ions can reach very high charge states in very short times. The subsequent electrostatic repulsion between these charged ions causes an explosive expansion of the plasma, generating ion flows with kinetic energies significantly greater than the thermal energies of the ambient plasma. This process has direct implications for the efficiency of neutron production in DPFs, as well as for the design of future radiation sources.

The results of these simulations provide a detailed insight into the microphysics of DPF hotspots, offering a basis for optimizing the performance of these devices. The ability to accurately model Coulomb explosion is crucial for predicting the energy distribution of ions and for understanding the heating and confinement mechanisms in these plasmas. This advance is an important step towards harnessing the potential of DPFs for applications such as inertial fusion and high-resolution radiography.