I don't have much to say about this yet, but I took some interesting data the other day that might inspire some people to think about it and comment. Basically, I'd been thinking about trying to look for the super hot gammas from the rare DD->He reaction, to see if that wouldn't be a good way to detect fusion, since heck, they should be so "loud" as to be hard to miss, or be faked out by something else -- running a fusor makes tons of X rays in the 0-power supply kv range, we know, but what if there's something else coming out we could use with a fairly simple detector and threshold? In re that -- this could go on the metrology thread, but until we figure out what this means, it's here since it IS fusor data as well, taken during a real run.
In the first picture, I have a Cs-137 source taped over the end of the NaI head, which is pointing at the fusor grid from pretty close in, with no lead intervening between it and the fusor - only the stainless steel tank walls.
Although I'm scanning slow (this is a roll mode that looks like the medical heart monitors you see on TV scrolling by) I have the scope set up to peak detect while sampling at a GHz, so it's catching all the peaks (and noise). Top trace is the NaI head, negative going pulses, and as you can see, the big 511 kev line from the source is about 1 major division negative going. The purple line is the output from the B10 tube preamp I'm working on (linear output) and the bottom line is an AC coupled faraday probe in the tank, far from the action. This setup is the same for the other pictures as well. Then I turn the fusor on, running not all that stably at this point (that's on purpose this time) to get kind of a sweep on the fusor conditions while we watch.
Personally, I don't think this is conclusive of much so far. There could be pulse pileup going on and we couldn't tell at this sweep rate, but when I look at it with a fast sweep (in other runs) I don't see much -- the NaI head is very short pulses normally. I will be taking more data on that at any rate. But notice that there are gamma outputs well above the 511 kev calibration here,
but not so big as to indicate much if any 16 megavolt either, unless this head is very squashed output in the higher energy region. We do see some stuff that, assuming linearity, might be well into the 1 mev region though. Protons from the other common pathway hitting the tank walls? At any rate, it's interesting that this seems to happen most often when the neutron counter is NOT counting, hmmm. Could it be that varying the conditions varies which reaction pathway is preferred? In general, it's drawing less power during the high gamma/low neutron periods...a lot less. If I turn my hope-o-meter way up, I could try and convince myself that looking for neutrons, instead of total energy is the wrong thing to do, and that there's a possibility of a higher Q mode that favors the non neutron pathway in certain conditions. Obviously there's more data needed here, but this is a start. Thank heavens for this nice Ghz multichannel scope and the linux tools (which don't exist for windows) that let me do screen captures quick! You linux people go look up GDS-2000 tools or gdsh and feel like the lucky kids on the block for awhile (also integrates into octave and gnuplot if you want fancier things).