The APELC HRR-TU-18 trigger unit utilizes a thyratron-based pulse forming circuit to provide the trigger pulse to the Marx generator. The unit also conditions and routes optical signals from the delay generator to control the charge and inhibit cycles of the thyratron HVPS and the Marx HVPS. The trigger unit facilitates pulse charging of both the thyratron and the Marx generator. The pulse charging mode of operation minimizes high voltage DC degrading effects (e.g. corona) and provides a safer high voltage environment since the default state of all power supplies is inhibited.

Additionally, the trigger unit provides LED indicators (Figure 4 B-D) on the front panel for notification of thyratron HVPS conditions. Front panel elements labeled in Figure 4 are described in the following paragraphs. Two key system diagnostics, Marx HVPS Analog Out and Thyratron HVPS Analog Out are available on the front panel of the trigger unit. These two signals can be monitored on any 1- M? oscilloscope channel by connecting to the BNC jacks on the front panel.