Science/Engineering/Technical forums

This was suggested by Richard Hull, to give credit where due, but for a different reason. The idea behind putting something like Pd or Ti onto the tank walls (in Richard's thinking) was to have the gas stored there, and the ionization happen right near the walls, ensuring full energy collisions in the center. My own thinking was a little different. All of myself, Tyler, and U of Wis had discovered localized hot spots for neutrons around the outside of the tank, which could have been neutron beaming (which would be difficult to account for in current theory) or just the fact that much fusion was actually taking place at the walls.

I believe the latter was the case, but at any rate, I tried it.
http://www.youtube.com/watch?v=2cr0yJRVFXg


For the second attempt (success) at the deposition, and

http://www.youtube.com/watch?v=_NdsyPyqvPA

For loading it up with D.

Well, this was interesting. I both put the metals on too thick, then overdid the loading with D. I wound up putting 20-30 times the D in there I'd usually use for a whole run, it just kept sucking the stuff up.
This however, caused flaking of the deposit, mostly from right where I wanted it to be...

So after cleaning that up, I did some runs. Instantly, I'm making 2x the neutrons as before. But there are issues with this. For one, the instant it heats up, the Pd (which I assume is most of the stuff) gives up the D, and output falls again, right back to normal. Pure Ti, and added cooling might have solved this one - the jury is out on that. But yes, it seems evident now that having D right at the walls improves things a lot.
I can easily make theory that is good with this one - it's quite possible for fast neutrals to be generated in a fusor, or even negative ions as they pass by the extra electrons emitted off the grid, then re-accelerated like in a tandem accelerator out to the walls by the field. Either way, it appears most of the simpler fusor theory as espoused all over (including fusor.net and most of the "pro" literature") is simply wrong.

It's interesting and worth knowing about the results of actual testing, though.

You made a Ti absorption pump!

Yup, that's about the size of it - I put the evap coil right where the grid usually is to get the coverage I needed...
But that Pd I put in there - bad mistake on two counts. One is that it lets the D go at pretty low temps compared to Ti, and since it's high Z stuff - it doubled my X ray count too. So it's all coming back off. I could use pure Ti if I added better cooling, I think, but now all it does is make the pressure harder to control as it warms up.