This image sucks, but it shows the new and final rod design for the plasma chamber. The bead journals on the side of the rod hold three ceramic beads evenly spaced around the circumference. They are turned down narrower than the rest of the rod to allow maximum fuel flow past the beads. The ends of the rod are rounded and a recess is drilled to accept two more beads, one on either end. The vortexing grooves are created with an engine lathe set to thread at maximum pitch (something like 4 threads per inch), and the reason they are created is to swirl the fuel and hydrogen for more complete cracking.
