I’m coming late to the proliferation issue and FF but now that we move forward I think we should consider our response to this concern. When we develope a garage sized device that could be distributed world wide this will come up! Of the two reactions DD and DT that could be used to produce a stream of neutrons I wonder how energetic DD is. Already DD has been used to produce the first pinch and I haven”t heard of anyone glowing in the dark nor has the FF “FO” been declared a hazardous site. The DT reaction might be much more active but you already need nuclear technology to produce Tritium. Then again, would FO really stand up to DT neutrons or flame out. Actually I’m not terribly worried about some rogue group refining nuclear fuel and constructing a nuclear device. The principles are well understood but the engineering is a nightmare (North Korea’s attempt was a dud). The greater concern is enriching deplet U238 to a sizable percentage of U235 that could blanket a dirty bomb. Hey! no one wants to rain on this parade least of all me but again we should consider our response.