Fusion Message Board

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Subject: Fusor Neutron Source for a SNUB?
Date: Dec 02, 7:22 pm
Poster: Tom Billings

On Dec 02, 7:22 pm, Tom Billings wrote:

I've often read, on this board, and elsewhere, that Fusors, even with D-T fuel, are at least a ratio of 10-100 from breakeven. While we have improvements like Bussard's magnetic field grids to look forwards to, I was wondering if we could combine the Fusor with fission methods to get past breakeven far sooner. This assumes that pure Fusor breakeven is _not_ just a 5-meter spherical anode away. (I hope that's a wrong assumption, but...)

There have been several proposals for Sub-critical Natural Uranium Burners (SNUB is my abrev.), usually involving large expensive acellerators as the neutron source. Their proponents claim they can go beyond breakeven while acellerating protons to 1.6 Gev to produce fast neutrons in quantity, for fissioning U238. That is far more work on each nucleon than a Fusor does to produce fast neutrons from fusion.

Uranium fission produces 200 Mev per nucleus split by a fast neutron. This is 80 times what a D-D fusion produces, and about 12 times what a D-T fusion produces. Can we use the Fusor as a source of fast neutrons for a small and inexpensive SNUB to produce multiples of the power fed into the Fusor?

Without hoving to worry about reactor criticality, a Fusor/SNUB combination might well be shielded more easily, and certainly with less mass than any critical reactor _I've_ ever heard of. In addition, it might be made cheaply, certainly compared to those proposed SNUBs with Linac neutron sources.

Can anyone here calculate just how close we'd have to come to pure Fusor breakeven to be able to use the Fusor as a SNUB neutron source to produce net power out of the system? At the moment, I'd put it at within 3-4 times of breakeven, using D-T fuel, assuming a 33 percent conversion into electricity. Am I being too simplistic and conservative in this calculation? Can we do this easier than I've seen with these simple numbers?


Tom Billings

Oregon L5 Society