Security ... think about it!
The key to the Marx lie in its solid state switches, which can quickly reconfigure the interconnection between cards. The cards charge in parallel, but discharge in series, so they dump their power into the klystron in one pulse of 120,000 volts. Impressively, because of the rounded edges of each aluminum rib, these 120,000 volts can sit safely in air without producing a spark. No mineral oil is required, just a simple metal cage. Additionally, the Marx transforms 96 percent of the AC power coming in to pulsed power going out, improving current modulator efficiency by one third.