A conceptual framework, supported and illustrated by computational modeling, is reported for a high-current snowplow discharge mode in coaxial electrodes consisting of a conical inductive storage section and a center conductor extension tapered in radius with a sigmoid curve from a 4-cm-radius to a 3-mm-radius stem. The inductive storage section can be loaded with Bθ flux by a relatively low-power snowplow discharge. In the sigmoid-tapered extension, the flux is shown to flow along the taper, increasing both field strength and flow velocity as it accelerates to a smaller radius, resulting in a petawatt flow of Bθ flux along the 3-mm-radius center conductor stem at 40 MA and 200 cm/µs.

Next, we present calculations of pinching a 0.8-cm-long pure deuterium-tritium (DT) target located as if in the stem. The pinch, formed when the petawatt flow passes over the target, was calculated to produce over half a gigajoule of DT fusion yield. Additionally, a half-scale 20-MA calculation was performed, and an approximate yield scaling formula was found with a dependence on the drive current to the fourth power.