Been awhile since I checked in. I've been pretty busy, mostly in good ways.
For the first time in a few decades...I have all the "normal person stuff" going and all at once. Instead of a little dorm room fridge - which itself was a new thing a couple years ago - I have a "real" fridge with a freezer now. And all that other stuff most take for granted - water at the tap, drinking water at another tap, a real gas oven/range...I can haz food! And at the other end, a warm place to...shower, wash clothes and so on.
Propane heat on top of the wood - no more getting up at 3 am freezing...
And on and on. My life for the last few decades would put most ascetic monastic orders completely to shame. I'm not living on champagne and caviar or anything, but that's by choice now. I guess it was before too, but kinda differently. Retiring young, as I did, from the rat race, and going off-rid, is a choice, but one that has consequences in standard of living (at least how most define that). Having developed all those good habits I've not missed the hooker and blow...and this seems pretty amazing.
So, I wanted to requalify a couple neutron detectors, since I've been doing preliminary RF drive stuff at the fusor in person, and those are my warning canaries. And it's a good thing I did - the sensitive He3 one had quit due to insect faff and a poor fix (compressed air blowout moved a pot adjustment).
I managed to put the fusor back the old way (DC everything) and have all that coincide with a dog and pony show for the neighbors who wanted one, so all good.
The results of those test runs were gratifying - everything replicated the past records or better, I was able to go 4 million n/s solidly and at a little lower power/higher Q than before (but believable), and the activation samples agreed with the electronic detectors, so that's all a confidence builder.
I note that with my small ultrasonic (42 khz) ion grid driver, that I can go substantially lower in tank pressure for otherwise the same results than with DC drive, and that the I/V curve on the main grid is "harder" even so. It seems the "RF" in this case gets a much higher percentage of the gas ionized. However, it is harder to get the ion grid "lit", taking more pressure initially than with the DC drive there, and it goes out easier if there's a hitch in something, requiring me to add a lot of gas and go through the tuning all over again. This is probably because it seems I only have a couple kV worth of AC there, it being a lot trickier to make a lot more than that and contain it. For this, I tried it with both a 1k resistor in the ground lead of the RF transformer - and the 10w one got warm - and with a 690pf one there instead, which is what I measured the DC volts across to estimate the AC volts, since the fusor as ever is a pretty good diode to ground when ions are present.
Mainly, I notice that with DC ion source drive, I see a big negative voltage on all the faraday probes, with the main supply making that bigger usually.
With "RF" (in quotes because, well, 42khz) there - I see a net positive on all the probes, and the mains being on doesn't really change that(!).
This is more pronounced when the ion drive is just that transformer secondary - it's warming that resistor drawing current through that "diode" which I assume means the ion grid is doing its best to collect all the electrons. Now whether that's just plasma polarization or it's really gotten most of them is in some question,
but when I look at the probes, while there is AC content, it's all way the heck biased off ground and never goes near it even on the negative half cycles.
What is interesting is that I can now see transit times between the ion grid and two faraday probes - one near and one further away, easily. I have not yet, but plan to, stick some series inductance in the main grid with this lashup and see what if any disturbances the main grid voltage undergoes in that setting. As is, the Spellman is a pretty stiff source and I didn't see anything of note with it directly connected. I'll have to shout out to those guys (Hey Cliff!) - those things have been utterly rock solid through what you'd have to call some abuse.
The skin cancers that have been cut off me have stayed gone...
On the downside, it's been super wet for months here, and I'm still fighting with that mold in the new crawl space. I discovered I can't get in there to spread anti-mold borax solution without inbibing enough spores to get sick, and am blowing air through that space 24/7, putting some strain on the electrical power system.
A torrential rain and lightning storm last night even took down a neighbor's off grid system long enough to crash all his servers! (Get well soon, Dave).
Now that's some EMI.
- Nasty stuff eating my man-cave.
This actually on treated wood and has caused a piece of plywood that separates the old and new (used to be the outdoor skirting) to disintegrate into pebble sized chunks on the ground...nasty. Most of it is in places down there I can't go into - only a couple inches clearance off the ground. I'm mulling what to do...
I guess it's always something. But hey, I'm alive to whine about it, and actually things are pretty good otherwise. Now if that girl I'm sweet on will just notice me...
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.