Optimized radial-transmission-line impedance transformer for a petawatt-class pulsed-power accelerator

Three-dimensional fully electromagnetic (EM) models are being used to optimize the design of a petawatt-class pulsepower accelerator.^1,2 In this design, a cylindrical array of linear-transformer-driver (LTD) modules³ feed power into radial-transmission-line impedance transformers followed by a vacuum line and convolute section which delivers the combined current to the load.¹ In the limit of small ratio of pulse width to one-way wave transit time, we have previously demonstrated that transport efficiency is maximized when the impedance profile is exponential but deviates for increasing ratio.⁴ We build on that result here with the construction of a virtual accelerator that includes a 3D EM model of a realistic next-generation design for the accelerator´s impedance transformer, and circuit models for the LTD drive circuits, vacuum magnetically insulated transmission lines, and load. Variable timing for each LTD module will enable pulse shaping.