January 2003 Archives

Well, Phil has got the ion gun design working on his fusor.  <heh>  Very cool.  Runs with less power, more easily controlled and still has higher neutron counts.  Gotta love this stuff, eh?

I did some DWF renderings of the clone of the multipactor ion gun patent and posted them on the fusor.net forum.  Phil mentioned he was looking at a multipactor design, and this was likely the patent.  Hopefully it'll be of help.

Got SIMION 7.0 today.  Not a bad program at all.  The demo is incomprehensible to someone like me, so I was glad to see the real version actually worked like I thought it would - I kept banging my head against whatever they did to cripple the freely downloadable version.  The manual is a satisfyingly thick, 1.25" of 8.5 x 11 paper entity, chock full o' detail about using the program.  This thing is an order of magnitude less in price than something of comparable utility to the Field Precision offerings.  They also have terrific student discounts, so rock on.

We'll see how long it takes me to start modeling even simple things.  It would be most excellent to have an analytical model of the chamber so I can play mind games with myself.  <heh>  Delusions of adequacy, I know.  Every one of these analytical/visualization tools are non-trivial to use because it's a non-trivial system.  But I should be able to get a simple grid modeled with a single ion.  Dave Cooper has promised to upload a SIMION Model which does just that, so that'll be cool to see.  So at least the diligent and talented can reproduce this :)  We'll see how well I make out.

Well, the fusor.net forum is really heating up (remember, I'm a geek, so scale "heating up" accordingly).  Phil Fostini started off the discussion by making a wonderfully generous offer of an ion gun to those that helped him design them from the parts he was making available.  Garrett Young and Phil are busily designing their first version.  I think the entire process is pretty cool.  A while ago Garrett was pushing for a more distributed fusor equivalent to ITER - amateurs colluding with each other to share knowledge and resources in this amateur research.  So far, people seem to be responding.  <heh>

From what I can tell, though, the first version will likely work.  The design, however will need some focusing electrodes I think.  I did some quick sketches in CPO-3D and it's clear that of the ions created, most will hit the BeO insulator - assuming a point ion source with momentum directed in a cone towards the accelerating electrode.  I'm not sure, but the accelerating electrode may quickly become a decelerating electrode.  I'm also thinking that the electric field from the fusor cathode may not have much effect through the BeO insulator with a small hole down the center.  I've been trying to model this with CPO-3D, but I haven't had much time to do so.  I'll try some more tonight. 

It could well be that the BeO insulator will block the decelerating effect of the accelerating electrode (i.e. once past the electrode, the ions will be re-attracted back towards the now decelerating electrode).  So the scheme might actually work.  I do think that unless focused in some way, it'll be hard to get more than a small percentage of the generated ions to go down the hole in the BeO insulator.  But even if they only get 10% of the ions, it will still be very cool.

And lord knows the second version of the ion gun will be far, far better.  :)

<heh> I just love this stuff.

Well, I'm feeling much better about things.  Usually a warning sign to small furry animals who might be innocently underfoot.  Garret Young asked a while ago on the fusor BBS "where's the science".  This got me worrying more about things that I had already worried about a lot.  Science is asking questions, forming theories, making predictions, constructing and performing experiments, gathering data, analyzing the results and comparing results with predictions.