Design of a reversible polarity linear transformer driver for positive and negative polarity e-beam diodes

Linear transformer driver (LTD)¹ accelerator designs have been proposed and constructed for a number of pulsed power experiments. The accelerators are typically optimized for one type of load with a specific load impedance profile. A design will be presented of an LTD accelerator capable of generating -3.5-MV pulses for Self-Magnetic Pinch (SMP) diode experiments, and +2.5-MV pulses for Rod-pinch diode experiments. In negative polarity, the electric field stress on the central cathode stalk exceeds the electron emission threshold. Emitted electrons are magnetically insulated and flow toward the load. In positive polarity, the field stress on the outer cathode conductor is below the electron emission threshold and the output transmission line is a vacuum insulated line without electron flow. Conversion from positive to negative polarity requires a simple change of power supply polarity and charge voltage. Results of circuit and electric field simulations will be presented.