Ion Gun Construction / Proposition

[pfostini]

That sound pretty close to what I am seeing. Less than a MA but the improvement on the fusor was striking. I was thinking if the guns could be tested in some type of linear chamber. Gun at one end and a target at the other and if we used lenses the distance from the gun to the target should be the same distance as the poiser is to the shell.

I have modeled my detector after yours mentioned in neutron counting FAQ ( 2" BC-720 ). Placed at 6" from the poiser.I spent the last few weeks doing daily background checks and gamma rejection tests to make sure I am only reading neutrons.

I was also looking at a multipactor design for non-filament guns. I'll keep you posted.

[hellblazer]

<heh>

Very cool.

My thought has always been that the current fusors are really poor ion guns. Take Richard's energy loss budget for any ion gun, and then apply it to the fusor, and even the worst ion gun will likely win (assuming the best for the fusor glow discharge).

I think the fusor is a decent accellerator, but from the australian experiments, it seems that the ions only have 25% of the cathode energy. Also, 60% of the ions were deduced to be H2+, decreasing the effective cross section. If the ion generator rips apart most of the moleculesthe H2 gas in addition to ionizing them (say in a duoplamsmatron), this alone could really increase neutron yield while decreasing power draw overall.

Not even bringing beam collision effects into play.

There might be a large percentage gain in just getting the neutrals out of the chamber so they don't collide with the ions doing the work. But this would require differential pumping in the guns to get rid of the neutrals. (at least that is what I believe it is for).

Just some random thoughts.

But again... Very cool results.

[hellblazer]

Attached are the dwf drawings from the multipactor ion gun patent (http://www.hellblazer.com/personal/mr_f ... erator.pdf ). It's a straight clone of the patent. Note it isn't differentially pumped, so that may be a good sign for us amateurs.

You can view and print the dwf files with VoloView, available as a free download (for registration, which isn't onerous) from AutoDesk at http://usa.autodesk.com/adsk/index/0,,8 ... 12,00.html .

Don't know if this is of any use to anyone, but at least it's a drawing with the parts worked out.

[3l]

More than one way to skin a chicken.

I approached ions the same way I've done fusors.
Do all of it.
I had loads of microwave ovens sitting arround....
Yes... I started fiddling with them while I was waiting on Ebay UPS deliveries. I tried the Bell Jar's plasma stuff. It really works. Don't loose couple this stuff please use the conductive epoxy for God's Sake!
Test first then believe!

I've been adapting the microwave plasma generator in the Bell Jar plasma experiments into a pretty safe ion source. I used a 600 watt magnatron as the source. It is coupled to a 2" copper pipe and cemented to the exit emitter of the magnetron. (I'm a chicken when it comes to high power microwave) You simply arrange Helmhotz coils on the test tube and make a feed entrance for deuterium gas at the front of the test tube I simply glued a plastic tube with model cement and used a fine tube for D2 gas input into a hole I drilled into the test tube. To extract the beam glue an extraction electrode in with ceramic cement.
With a simple drilled baffle plate made out of steel the ions exit the holes while the microwave stay in....I simply copied the hole spacing on the front of the microwave oven. ( I hate scrapping off paint ) If you were really cheap just cut it out of a microwave oven door screen. The really lazy approach is to just drill a test tube size hole in the door the cover it with a microwave shield. The vacuum inside the ion generator is pumped externally without too much danger or problems of interfacing simply goes into the vacuum chamber of the fusor. I'm still playing with it..... I will release details as I have them. Microwave power without the design hassle of turning it loose in your fusor. I was gonna announce it a month from now...but Phil has broken the ice on the gun issue.
I will post pictures as soon as I get my new camera out of layaway.

Fusion is fun!
Larry Leins
Fusion Tech

[r_c_edgar]

Hi everyone,

Please direct the discussion to the new "Ion Gun Design and Construction " forum. Finish off any running dialogs for the sake of continuity, but anything that's even sort of a new topic should go in the new forum.

Thanks!

--Ryan Edgar

[Starfire]

Thank you Ryan -- again -- Your work is appreciated.