Reply To: Focus Fusion Rail Gun

[asymmetric_implosion]

There are publications by LPP that suggest the temperature was achieved. The measurement leaves some questions but it is a good first look at it. They used the hard x-rays generated by the pinch to estimate a temperature. The potential problem is the high energy gamma rays created when neutrons interact with the stainless steel vacuum vessel. I’ve encountered it in the past and it can screw up measurements. The measurement I’m waiting to see is the soft x-ray spectrum of continuum radiation from the deuterium. Folks have done it before and it provides a pretty reasonable estimation of the temperature. It tends to be a little on the cold side so it is a good lower bound. The density again has been estimated. You really need to do an x-ray transmission measurement to measure the line density and infer the actual density from x-ray images of the pinch itself. Nether has been done so the conditions for D-T breakeven have been inferred rather than measured. This does not mean the results to date are not promising, but more needs to be done. The other option is to load the machine with DT and go for it. It would be a huge political win to show breakeven. The cost of the experiment would be enormous as T is involved but a successful demonstration might eliminate some of the funding problems. Big risk, big reward. The other option would be to move the machine to a national lab for the test. It would be distracting and difficult but again, big risk, big reward. You could also get some DOE buy in as their lab made fusion viable.