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Registered Member #1591
Joined: Wed Jul 16 2008, 06:34PM
Location: Livermore Ca
Posts: 14
Attached is a photo of my prototype cascade tube for a VanDeGraff driven particle accelerator. The link is a quickly done youtube presentation I have put together.
Registered Member #1591
Joined: Wed Jul 16 2008, 06:34PM
Location: Livermore Ca
Posts: 14
Duxseal. A consultant in the accelerator industry told me that for this purpose it should work quite well. However I have never personally tried it. If it dosent work, I suppose I will have to invest in a small quantity of Apezion.
Registered Member #135
Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735
That's really sweet! Hope it works! I am kinda bummed that you're going to destroy the CRT for the gun though. Another thought would be insted of killing a scope CRT for the gun, get a triple gun from a TV set and that way you can intensify your electron stream up to 3x of that scope gun.
Also don't be sruprised if your seals don't work. I think in this case, with the vacuum you need, that you need to etch the surrounding glass under your seal to prevent leaks. I think you may have to first prepare a quarter sized area for sealing by cleaning with perhaps Chromic Sulphuric, then etching briefly with Nitric Biflouride (safer then HF, but still dangerous). That I think would prepare the surface to adhear to the sealant.
You might want to also talk to Bored Chemist to see what he thinks. You may be able to get away with diamond abrading the surface for a good bond, I'm not sure because I'm not real experienced in vacuum as of yet.
Registered Member #1591
Joined: Wed Jul 16 2008, 06:34PM
Location: Livermore Ca
Posts: 14
Ahhh, the vacuum bugs. I am quite aware and expectant of them. Regarding Duxseal, I was unaware of this product until I read this thread in the fusor.net forum:
Your suggestion at prepping the glass is excellent. In the past I have used very fine diamond grit sandpaper with excellent results. But the idea of a dilute HF solution may be even better. It just so happens that I have some.
Normally I would use Hysol 1c epoxy for an application like this. Its vacuum rated and very durable for exterior applications which are not suseptable to heat, plasma, or mechanical stressors. However, epoxy is somewhat permanent. This cascade tube is being designed for easy tear down and rebuild. So the exploration of various waxes and putties is a must.
Just as a reminder, the pictured tube is an engineering prototype. It will never be used for anything other than a blueprint for the real model.
Account deactivated by user request on 6/11/2009. Registered Member #1071
Joined: Fri Oct 19 2007, 02:13AM
Location:
Posts: 44
I dont get it, what is the deal with your vacuum seals. Usually for stuff like that you can just use orings with some vacuum grease on them. If using orings surface prep is a non issue, as long as it is sorta sanded flat and there are no scratches they seal. What type of pressure are you interested in getting down to?
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Particle Accelerator - Stage One
