Circuit Simulations of a 1 MV LTD for Radiography

A 1 MV linear transformer driver (LTD), capable of driving a radiographic diode load, has been built and tested. A circuit model of this accelerator has been developed using the BERTHA circuit simulation code. Simulations are compared to data from power-flow experiments utilizing a large area electron-beam diode load. Results show that the simulation model performs well in modeling the baseline operation of the accelerator. In addition, the circuit model has been used to predict several possible fault modes. Simulations of switch prefires, main capacitor failure, vacuum insulator flashover, and core saturation have been used to estimate the probability of inducing further failures and the impact on the load voltage and current.