Thought I'd add a few related pix of the pi cam setup here. I improve the optic a big (Thanks BillF for finding the glass) and locked things down better, while adding additional X ray attenuation. Not that the latter matters, it was already so good most of our X rays were actually neutron capture-gammas from all around, not from the fusor directly, but hey, it's nice to be complete. So, here's what it looks like at the camera mount.
- Here's the pi cam looking through a 2.5 diopter lens into the tank from above, with lead covering the unused part of the viewport. The extra IR Filter is just stuck on with black tape, and some hot glue.
Baling wire! It works, and is nicely adjustable with pliers. Here's the view it sees (more or less, I re-aimed it a little I think).
- A little green from the extra IR block, but good anyway.
You can see my main grid, and at the lower right, the ion grid, which is pretty gross as a fusor grid, but it works fine for making ions when the gas pressure is so low the main grid won't "light off" at all. In fact, you could think of all this as a very high voltage enhancement mode p-fet - it takes 5-40kv on the ion grid (depending on pressure), and from 1 to about 12 ma to bias the main grid "on" at 50kv and any current I want - the limit isn't the power supply here, it's what would melt. Power gain is around 100 used as a "fet" of "reverse polarity vacuum tube". But transit times are very long compared to an electron tube.
I made a lead hat for all this so the X rays from there don't leak out into the room where the air scatters them around the shield between this and the operator position.
- Showing the "hat" and also the pi itself in it's little box.
This also shows the pi in the plastic box. In that box are also a laptop walwart (overkill) and a 5v 2a switcher (more overkill) to run the pi, with wires soldered right to it's board (not overkill, the microusb was a very stupid choice on their part).
The pi is running a high power wifi (2.4ghz) from adafruit on one of its USB ports. I got tired of running wires and switches, and this is safer for my network if something should pick up a big spike anyway. You don't actually need that little display, or even to log in for this to work. It is nice to see it if it crashes so you know why, sometimes, though. I suppose you could get that by SSH'ing into it, which does work fine too. All this stuff for the streaming via raspimjpeg and apache gets run at boot anyway, and runs if you surf to the pi's page.
Of course, it looks better when the fusor is really running. This one is cropped down to just the action here:
- My line focus is just to the right of one of the grid wires, but I need to rotate the grid so you can see it better next time I break vacuum.
So, this one's pretty much a done deal now. I don't plan on fooling with it much more unless I get into the source code for the thing and fix a few bugs it has with settings not all working as they should and so on. Mechanically, we're there except for a cable tie to hold the box on there no matter what. It's better than this in most regards. I can't seem to get my handheld camera to NOT focus on the screen just past the glass, and of course, there are reflections from the 3 layers of leaded glass, which is why I often take pix at night...this time not.
- End on with normal camera that likes to misfocus on the screen next to the glass.
The beams and focus are a lot smaller to the mark 1 eyeball than this shows, misfocus by the camera, not my fusor in this case.
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.