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[asymmetric_implosion]

Henning wrote: So graphene covered (highly conductive) carbon rods would be best? As the current only flows on the surface that’ll be enough…

See here: https://focusfusion.org/index.php/forums/viewthread/564/P15/#5633

You are likely to burn off 10-20 nm of graphene in a single shot. If it doesn’t burn off right away, it will be etched off by the hydrogen plasma very quicklyi. Hydrogen plasma etches graphene or graphite very efficiently. 20 nm is nothing. People etch microns of graphite per minute. The message is that the electrodes are consumed during operation. The mass loss is ~ 6 microgram per shot for a 60 kA device. If one assumes scaling based upon linear current density on the electrode, FoFu-1 will consume more like 3 MA/60 kA*6 micrograms per shot or 300 microgram per shot. You can calculate the material loss over the anode surface if you know the exact dimensions. At 2.5 g/cc in a 20 nm layer it won’t take but a few shots to erode the graphite and leave the underlying material. If material is Beryllium, it will be eroded and activated based upon x-ray flux. Let the ES&H problems begin.

From my experience, the extra x-rays from tungsten are far less of a problem than any other material problem. No material is perfect so one must compromise. Repetition rate operation, as will be needed for power production, has shown on several experiments to be best with tungsten at high current and moly at modest currents. No point in reinventing the wheel when the relevant data already exists.