Frank,

Some important differences between the Jacob’s ladder and the PF. The Jacob’s ladder climbs mainly due to convection; the arc is hot while the surrounding gas is cold. The travel speed is limited by typical convection speeds. In the PF, the plasma motion is driven by the magnetic pressure behind the sheath. Like a balloon, the sheath blows up as the pressure increase and pushes the plasma along the channel between the cathode and anode. Magnetic pressure can only exist where there is current flowing so the pressure is concentrated between the anode and cathode.

The plasma focus circuit is a simple design on paper. You want a high voltage capacitor, a low inductance circuit and a low resistance circuit. The mechanical part of the system must withstand the current pulse which for most small plasma foci is easy enough. The optimum electrode design is typically a cathode diameter that is double the anode diameter. The anode radius is optimized when the Lee’s drive parameter is 70-90 kA/cm-sqrt(Torr). D=I_max/(a*sqrt(P), where D is the drive parameter, I_max is the peak current, a is the anode radius and P is the deuterium gas pressure in Torr. You cannot choose the pressure arbitrary. It must be between 1 and 20 Torr for most systems. The pinch effect is demonstrated from systems of a few amps to 26 MA. There a practical problems of small pinch devices. Pinch devices above 100 kA are easy enough to produce and literature is fully of devices of this scale.

Good luck learning about PF device.s