Lithium vapor injected into fusor with deuterium fusion initiation.

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gamempire
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Re: Lithium vapor injected into fusor with deuterium fusion initiation.

Post by gamempire » Wed Feb 25, 2009 9:56 pm

Attached is the DWG file for the design I posted.
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[The extension dwg has been deactivated and can no longer be displayed.]


Lithium trick
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Re: Lithium vapor injected into fusor with deuterium fusion initiation.

Post by Lithium trick » Wed Feb 25, 2009 11:48 pm

Dave, We have not talked before, here on this forum, but here's a thought, a sacrifice disk/ cover glass, can be placed in front of the real window to take the sputtering contamination beating from burning in a grid. A simple solution as it's done very often for expensive laser lenses used in Laser cutting, they typically run around 15 bucks or so each in orders of 10 or more, and are made out of KaCl, as a expert in CO2 laser cutting I have seen them used many times commercially, saving my customers thousands of dollars a year as beginning operators during training tend to destroy the focus lens during their training months. I don't use them and have never needed to do so as I have 15 years of cutting behind me, so my training days are well behind me. I don't trash optics at all.

Many good acids will clean out a chamber as you pointed out. My thinking is though a inner grid would be worth exploring as it would collect the majority of contamination by way of electron flow to the inner grid. Would this not be true? Of course these devices do need a burn in period understandably to clean up the chamber and grids.

Rick

David D Speck MD
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Re: Lithium vapor injected into fusor with deuterium fusion initiation.

Post by David D Speck MD » Thu Feb 26, 2009 12:15 am

Rick,

Thanks for the info. I had no idea that you could get optically clear KCl discs in that size so inexpensively. Any suggestions as to a source? Perhaps we could arrange a group buy to get past minimum quantity requirements.

I though I would just use discs of flat window glass, or Pyrex, if the ordinary glass shattered. I could probably turn off the system pretty fast if I saw a failure of the sacrificial window. Not sure where I'd find Pyrex discs, though.

Any reason to think that the KCl would have a significant advantage over Pyrex, especially since we're only using them as viewports, not as high power IR laser transmission windows?

Dave

Lithium trick
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Re: Lithium vapor injected into fusor with deuterium fusion initiation.

Post by Lithium trick » Thu Feb 26, 2009 1:17 am

Dave, Here's a tip.
lenssavers.com The company is International Crystal Laboratories. You can look on their web site for the lens saver product. They tend to be hydroscopic, so one must keep them dry, but the system would be under vacuum, by simply closing a valve at the vacuum pump to hold the vacuum while not running the system. Why waste time out gassing the system again unless you are doing internal maintenance? Pyrex blanks could be sourced from Edmonds optical, but I will warn you they are not a source I recommend as everything they sell is expensive as heck.

I, myself, would look around on the web for vacuum fitting companies, and in particular ask about view port windows, and shield windows for this application. I chose ICL simply as a cheap throw away heat tolerant window that I knew could be made to work. Many other options should work as well. No plastic though for obvious reasons. I would suggest a local scientific glass shop Weiss Scientific Glass in Portland, OR. Or Hayward Quartz in Hayward CA, both companies work with Quartz glass, and they can make these windows however I have no idea what they would cost. The whole deal depends or the size of your view port. So those are just a few idea's for suppliers. Certainly there are many options here. No need to waste a good view port window because of some contamination.

I'm still interested in the dual grid setup as originally designed, I have specific reasons for this choice.

Rick

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Re: Lithium vapor injected into fusor with deuterium fusion initiation.

Post by Lithium trick » Thu Feb 26, 2009 2:32 am

Josh, I have downloaded a DWG reader.

I have also worked up my copy's of the Auto CAD file you posted and I have the math all worked out, I plan on cutting them out this week if I can get the machine time. It's just a couple of minutes on the machine, I'll cut one set, and check out the assembly. Then cut several sets just to have them around, I can get double insulated high voltage wire I use for laser repair, and the PFA tubing I use to triple insulate this wire, it's proven beyond 70,000 volts at WAY BEYOND the currant draw I could ever put through it. So the next step is the biggest hurdle, the vacuum system, by far this will be the biggest part and expense so far and the instrumentation to run it, and hold a set point A good set of idea on the grids I have posted already, it seems to me a long term issue for system performance and stability. The sputtering issues do concern me, I hope you find it useful. How well do the stainless steel ones work for you, and when do you start to see the sputtering problem show up at what voltage and what amperes? You indicated you had to burn out the cavity and grids for about three hours with helium, how is it now?

Rick

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Carl Willis
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Re: Lithium vapor injected into fusor with deuterium fusion initiation.

Post by Carl Willis » Thu Feb 26, 2009 2:48 am

This thread seems to be treating a number of disparate topics at this point. It would be better, going forward, if individual topics were given their OWN threads or put in the appropriate existing threads. For instance:

- Josh's laser-cut grid and related discussion
- Optical windows and how to clean them
- Cold neutron beamlines
- Commercial neutron generators
- Be(a,n) neutron sources
- Lithium vapor and whatnot, previous thread located here (viewtopic.php?f=14&t=6731#p42414)

Some of these topics do not really even belong in Fusor Construction and Operation, but in the other forums.

The disadvantage to having long, multi-directional, Faulknerian stream-of-consciousness threads is that it defeats the site's organizational structure and makes it harder to search out material in the archives.

Thanks...

-Carl
Carl Willis
http://carlwillis.wordpress.com/
TEL: +1-505-412-3277

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Chris Bradley
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Re: Lithium vapor injected into fusor with deuterium fusion initiation.

Post by Chris Bradley » Thu Feb 26, 2009 4:14 pm

I was at the point of posting similarly.

What *was* this thread about?

gamempire
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Re: Lithium vapor injected into fusor with deuterium fusion initiation.

Post by gamempire » Thu Feb 26, 2009 7:16 pm

Carl Willis...bringing sanity back to the insanity

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