Reply To: would nuclear energy really be accessible to all?

[Allan Brewer]

I’ve been doing some rough calculations based on what has been said so far:

Using Ohm’s law (apologies if I am being naive) for 1MA through a 20nm skin of the copper electrode does indeed give an answer, in the expected range, of around 2MW of heat from the anode and about the same from the cathodes. Beryllium has twice the resistivity so would double the heat “problem” (and increase the power required to initiate each shot?).

jamesr – I was thinking more that if the anode had a 10 to 20nm thick skin of something like carbon in some highly conductive configuration (eg graphene) then this would mitigate the surface vaporization and lessen the joule heating due to the large current flowing in the skin compared to beryllium.

The resistivity of graphene is four orders of magnitude less than copper so would theoretically reduce the electrode heat to 200Watts – easily manageable, and presumably drastically reducing the power required to initiate each shot.

Whilst looking at this I had the further wacky idea that if the electrodes were coated with a “high-Tc” superconductor and cooled with liquid nitrogen then we could eliminate the resistive heat generated completely – after all we would have more than saved enough power to drive the necessary refrigeration. (But even though superconduction is used to drive electromagnets I understand there is some problem when magnetic fields are changing , so the plasma/plasmoid presence might preclude superconduction?)

Finally just to note that thermal radiation from the plasma & plasmoid cannot be calculated using the Stefan-Boltzmann law (gives a silly answer) – I leave the physics of the emmissivity of high temperature plasma to experts.