I got the cage finally built. Must say that it’s a nice milestone. I
had ordered 12 great circles, laser cut, from
www.quickparts.com. It’s like
casting a spell, or invoking daemons to carry out your will. You upload a
CAD file of what you want, and about 5 days later it comes back to you in
manifest form. On the right
is the finished product.
Brent came over and we talked about Bussard’s patents, electron gun design, etc.
I now have 4 circles cut and bent. We tied three bow-ties together with
twine and it is surprisingly strong. Geodesics always are, and it’s nice
to see that this one was no different. But the three bow ties form the
surprisingly accurate cage shown on the
cage is working out great. Only six pieces, some easy bending and only
thirty welds. I can keep the cage pieces aligned in the correct geometry
using copper wire to replace the twine that currently holds the folded great
circles together. Thus making it far easier to accurately weld together.
The picture on the right
is what the great circles look like after I’ve worked out my forearm with the
shears. The result is definitely dished, but surprisingly well formed.
Brent was impressed with how accurate they were, despite having been cut with
shears. Plasma cutting would definitely improve tolerances, but the cage
looks good enough for government work.
I had the brilliant idea of building the cage from folding the six great circles
of the icosidodecahedron. I’ve always wanted to build these cages from
great circle folding, but for some reason I blanked out on the simple folding
shown in figure B on the right (click for larger version).
I just found the coolest thing. Stanley Humphries’
Principles of Charged Particle
Acceleration , unabridged, in PDF form. This 1986 book is chock full
o’ way cool stuff. Been working like a dog – well, two dogs, but who’s
counting – and have mostly been trying to see how I can get movement on my
chamber – <sigh>. Did get a quote from
regarding cast pieces for the cage faces.
So hopefully Brent and I can play with the electron gun we pulled out of the
TV over the weekend. I have to remember to get some electrical feed
throughs from Duniway.
Anyways, check out the above PDF book. Well worth the time.
Well, Brent came over on the weekend and we farted around a bit and actually
managed to successfully extract the electron gun from the miniature black and
white TV I bought just for this purpose. It was actually pretty easy.
Got back from the
Hacker’s convention late last night. Had an absolutely fantastic time.
David Leibs roped me into talking about this project to the group, and it was
pretty fun. I talked to a couple of real physicists about it and had a
couple of great conversations. One was dubious of the magnetic cage
efficiently confining the electrons. Another thought I would have to get
to 10-9 in order to get the electron and ion guns working at all.
This is something I see as a possibility, but it doesn’t seem intuitively