Multiphysics simulation of a pulsed relativistic electron beam interacting with the anode of a self-magnetic pinch diode

This study presents a multiphysics and multiscale simulation of the interaction between a relativistic pulsed electron beam produced by a Marx generator with a metallic target. In a first step of the calculation series, the operation of the generator is calculated using a 2D Maxwell–Vlasov Particle-In-Cell code. This calculation step allows for the electromagnetic coupling between the generator and the self-magnetic pinch (SMP) diode and restores the spectral and angular characteristics of the electron beam impacting the anode. From these electron characteristics, the energy deposition of the electron beam into the target is computed via a 3D Monte Carlo method in a second step. This energy deposition is then used as the entrance parameter of a 1D hydrodynamic calculation in a third step. The different results of this calculation series are compared with experimental measurements such as the current and the voltage of the diode, electron beam focal spot, dose rate, target deformation velocity, and plasma temperature and density. This approach, combining calculation and experimental measurements, provides a precise quantification of the mechanisms at work when a target is exposed to a high dose rate. The applications of this analysis method concern the framework of the influence of the impedance collapse during the operation of SMP electron diodes and the generation of well-defined mechanical stresses for the validation of equation of states and the modeling of fracturing under high pressures.