Magnetic ion source

[Doug Coulter]

To do the next set of experiments with ion trapping and recirculation, I need some ions. And I need them at pretty high vacuum to start the parameter sweep I think I'm going to want.
Given the task, I can't depend on - and don't want - the main trap to generate them via cascade ionization under Paschen's law - that would disturb what I'm trying to measure, and wouldn't
work anyway at the starting vacuum.

While the microwave ion source would probably work - it has before at e-6 mbar - the original got broken and detuned, and I'm not sure I want to deal with that, and what it would take
to get ions into the new vacuum setup - that would involve some making of holes and welding of flanges and so on.

Since I know the vacuum gage makes ions...well, here's the big brother to that. This has REAL magnets, and I'm somewhat surprised I got away without blood blisters or worse.
It took some real jigging and prying of things to get the magnets off their original keepers! I'm showing something over 5000 gauss in the gap. I might only get a microamp or so, but
that'll do, easily.

Anachronisms 'r us. Modern RE magnets, LED lighting, shot on top of a woodstore.

Not shown yet are some copper heat shields made of flashing to protect the magnets from direct impingement. Because I haven't made them yet, but it'll be a simple cut with scissors, bend with fingers and insert.

In case you're wondering where I expect the ions to come out, here's a top view.

one of the magnets has a hole in it

Obviously I've gotten a little rusty with the welding, but it'll work. This is sized to easily fit through the removable window on the test vacuum system.

[Doug Coulter]

Took a little longer to get to testing for unrelated reasons - homestead stuff (generator repair, gasoline pump install, water pump hysteresis adjust, wood, propane, food, Dr).

It works on the first try!
I'm using a voltage-doubled and current limited CCFL inverter to produce maybe 1.5kv or so here - with what I'm seeing I might want to go to a tripler to get more current at the higher vacuums, but..this would work as is.
I'm measuring the positive voltage induced on the main grid - even with its HV diodes forward biased and their bleeder-dividers present (but it's a lot of them in series) here.
That little scope I recently bought to make troubleshooting in "hit your head" crawlspaces where my LAN of things nodes tend to live is shown here - I'll have more on it later. $51 and change, worth it.
Here it's just showing some of the AC from the CCFL inverter. It's not going to beat your Tek zoomo $5k scope, but then, that one doesn't fit in my shirt pocket, either.

putting around 3w in, mostly going to various parasitic stuff.

And it looks kind of cool, here in some He (mostly, we're fairly close to the base pressure for this system - the turbo has barely almost survived a couple inrush incidents).

Nevertheless, it glows.

And at pressures far below the ~ 5e-3 mbar the big fusor would run at (gotta make another one of these!):

The little pump station

So, "real soon now" I should be able to go places and do cool things...more when there's more.

Yahoo!!! Things working the first time is how I like it, but still not as common as I'd hope.