asymmetric_implosion wrote: A lot of science needs to be done before you can claim to understand the economics because you don’t know what you need to make the system work. Gain is a necessary but not sufficient condition to produce a viable fusion power plant.

I agree that gain would push the supporting technologies like switches and capacitors (yeah, these guys burn out faster than the switches). The potential pitfall is pushing beyond fundamental physics limitations of materials. Many of the problems with the switches and capacitors are material wear and failure. Thyratrons are already pushed to their limits on the material side by using hydrogen as the source gas to limit ion damage on the cathode and refractory materials when merited. There is nothing left that can be done. Diamond switches, which have been mentioned on this site a few times, are difficult to trigger because of the large band gap that makes them large voltage hold off. The purity of the material is just getting good enough to approach the theoretical hold off limits.

Information on Thyratrons is available from the vendors, English Electric Valve and L-3 Communications Electron Devices. The bulk sales rates are just guesses based upon the limited numbers I buy. The cost per J for the solid state number is based upon a plasma focus built by SRL that stored ~2 kJ and cost ~$2M to run at 80 Hz and 200 kA.

There are vendors who can customize equipment to your specifications. I checked and found R. E. Beverly III & Associates. They make spark gap switches that are very similar to the one used by FoFu1. They have a list of products for high voltage work.

This article describes a switch that is related to the thyratron but more rugged and could be cheaper. Characterization of high power Pseudospark Plasma Switch (PSS)

Further developments are just waiting for enough demand.