Modeling Temporal Spot Size Evolution on a Linear Induction Accelerator

The primary goal of most linear induction accelerators is to generate the best possible spot size and dose for radiographic measurements. Arguably the most critical moment in generating the spot size and dose is the electron beam to target interaction, where it is important that the beam be properly focused on the target. It has been previously studied 1 on DARHT that the Bremsstrahlung converter target can generate ions which alter the radiation spot during the pulse, thereby accelerating the ions away from the converter target and causing the spot to change during the pulse. It is important to understand this process using computational codes and to be able to predict this phenomenon for the future Scorpius project. Results will be shown of the PIC code LSP, modeling experimental data from the first axis of DARHT, which will further benchmark the LSP code and help with predictive capabilities of the Scorpius accelerator.