System integration of a coaxial ferrimagnetic nonlinear transmission line array

This paper describes the system integration of a four element, nonlinear transmission (NLTL) array. The HPM system components include a negative polarity 40 kV capacitor charging supply, a trigatron spark gap, a solid-state trigger generator, four delay lines with biasing coils, four coaxial ferrimagnetic NLTLs with biasing coils, eight dc current supplies, and four TEM horn antennas. A National Instruments cRIO FPGA based controller is used to interface the capacitor charging supply, the biasing coil power supplies and the trigger generator to a laptop based GUI. In order to minimize impact from EMI, all lines were properly shielded and the data acquisition equipment was located a sufficient distance away from the NLTL array. The GUI consists of options for controlling the current output on all 8 power supplies for biasing purposes, as well as pulse options that include repetitive pulsing based on the number of pulses or for a specific length of time. Pulse duration for the capacitor charger, the command charge, and the trigger can also be adjusted. An emergency stop button is included for safe shutdown of the trigger generator and all power supplies. A diagnostics setup is outlined describing the placement of inline coaxial D-Dot probes and a high voltage probe for laboratory testing.