LSP simulations of the Self-Magnetic-Pinch-diode

The Self-Magnetic-Pinch (SMP) diode has been modeled in LSP. Presented within this body of work are 2D simulations of the 8 MV Merlin SMP with an optimized anode-cathode (AK) gap and an AK gap that is 50 % larger. Anode plasma is simulated using LSP´s hybrid fluid-kinetic algorithms. Both simulations demonstrate falling diode impedance during the pulse, possibly due to gap closure as the anode plasma expands. Output from LSP is used to generate predicted radiographs of test objects using MCNPX and BIE forward modeling. No significant difference is found in the resolution of the predicted radiographs for the two geometries. 3D simulations of the 3.5 MV Eros SMP are also presented. Deliberate asymmetries in the diode setup are simulated to test the SMP´s susceptibility to 3D failure modes. It is found that asymmetric emission thresholds for the anode and cathode do not produce lasting significant asymmetry during the pulse. However, an angularly misaligned anode produces lasting asymmetry and spot movement.