Final Design

For posts specifically relating to fusor design, construction, and operation.
bk8509a
Posts: 40
Joined: Sat Oct 31, 2009 8:47 pm
Real name:

Final Design

Post by bk8509a » Mon Feb 01, 2010 2:36 am

Welp, here it is. After quite a bit of time my whole team has our design worked out, complete with 6" view port! Parts will be ordered in the coming week and assembled. Some holes/tapping will be needed but it shouldn't be too tedious. Tell me what you think.

If you're curious I can send you the budget. Also, just picked up a pump and an oil mist filter for 202 total on ebay. Things are starting up.

-BK
Attachments
Chamber3.pdf
(26.95 KiB) Downloaded 78 times

Tyler Christensen
Site Admin
Posts: 551
Joined: Tue Feb 24, 2009 2:08 am
Real name:

Re: Final Design

Post by Tyler Christensen » Mon Feb 01, 2010 3:23 am

I would suggest not putting your pressure transducer on the same tee as your vacuum pump, I have found that putting gauges on the same branch-out as either the deuterium input or the pump output can cause meaningless results due to imbalanced pressure in that area due to either the higher or lower pressure of the chamber inlet or outlet respectively.

User avatar
Doug Coulter
Posts: 1312
Joined: Sun May 27, 2007 7:18 pm
Real name: Doug Coulter
Location: Floyd, VA, USA
Contact:

Re: Final Design

Post by Doug Coulter » Mon Feb 01, 2010 4:09 am

Looking good indeed! If your experience parallels ours, I think you are going to find that there's a certain optimum ratio of inner grid size to outer electrode, and you outer is on the small side for the inner size. Paschen's law will also mean that with the smaller outer size you'll need either more pressure or more volts than the guys running 6", though that size isn't magic either (we have run from 4" to 14" for that number and have made them all work, some better than others). I am just now getting ready to put some details of tests we did on these parameters on my site, I'll link back here when I do.

This is not to tell you to change anything, just things to look for when you run.

Best of luck, this looks like a winner.
Why guess when you can know? Measure!

User avatar
Steven Sesselmann
Posts: 2111
Joined: Thu Aug 11, 2005 1:50 am
Real name: Steven Sesselmann
Location: Sydney - Australia
Contact:

Re: Final Design

Post by Steven Sesselmann » Mon Feb 01, 2010 6:13 am

Brian,

Nice drawing....

If I were you, I would forget the word "Final" in connection with Fusor design...

Before you know it you will be working on MK5 and your first design will be somewhere in the junk box, and only good for spare parts

Steven
http://www.gammaspectacular.com - Gamma Spectrometry Systems
https://www.researchgate.net/profile/Steven_Sesselmann - Various papers and patents on RG

User avatar
Doug Coulter
Posts: 1312
Joined: Sun May 27, 2007 7:18 pm
Real name: Doug Coulter
Location: Floyd, VA, USA
Contact:

Re: Final Design

Post by Doug Coulter » Mon Feb 01, 2010 6:42 pm

Good point Steven, I'd second that one. The glory of science is to make progress after all, and that implies that what you know now is incomplete, so "final" is a really strong word to put on things.

This design does look like that was in mind at the time though, pretty easy to change things with all that nice access to the innards. Good show!
Why guess when you can know? Measure!

Starfire
Posts: 1482
Joined: Wed Oct 24, 2001 6:14 pm
Real name:

Re: Final Design

Post by Starfire » Mon Feb 01, 2010 8:20 pm

That sounds like experience. Steven.

myID
Posts: 139
Joined: Wed Jun 25, 2008 6:16 pm
Real name:

Re: Final Design

Post by myID » Mon Feb 01, 2010 8:30 pm

Hi-

I also agree- it will grow and you will have a lot of changes- BUT- looks like a great (i.e. flexible and modular) setup to start with.
I also made the experience Tyler made- due to different "flow" in high vacuum it is important to locate the pressure sensor "looking in the chamber" and not in the up- or downstream connection.
And- you will have to feed your D2 somewhere
What CAD software did you use? Do you have a library with vacuum parts? That would be handy! Nice drawing!

Greets
Roman

User avatar
Carl Willis
Posts: 2841
Joined: Thu Jul 26, 2001 11:33 pm
Real name: Carl Willis
Location: Albuquerque, New Mexico, USA
Contact:

Re: Final Design

Post by Carl Willis » Mon Feb 01, 2010 9:25 pm

Hi Brian,

Looks very nice.

I advise caution on the large viewport. While suitable for eye candy, it's an expensive accident waiting to happen (due to electron heating). Windows charge up during operation and the flashover can be quite disconcerting.

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

User avatar
Doug Coulter
Posts: 1312
Joined: Sun May 27, 2007 7:18 pm
Real name: Doug Coulter
Location: Floyd, VA, USA
Contact:

Re: Final Design

Post by Doug Coulter » Mon Feb 01, 2010 9:57 pm

Here I can't live without the eye candy, so I use a sacrificial window in front of the viewport glass, inside the tank. I use the relatively conductive pyrex (orders of magnitude more conductive than quartz) clipped into the flange stub for that, and after awhile a little sputtering onto it makes it even more conductive. This piece you can take out and dunk in acid when it gets covered with sputtered metal as well, something you'd not want to do with an expensive viewport. At any rate, this protects the expensive piece and brings charge accumulation troubles to a halt. And you get to keep the eye candy.

Here is a link to the piece sitting on the table:

http://www.coultersmithing.com/Runs/FusionClub.html

I don't have a good link just now to the thing in place just behind my 6" door/window, but that's where it lives and it solves all that just fine. I am in the process of updating that site, so stay tuned.
Why guess when you can know? Measure!

DaveC
Posts: 2346
Joined: Sat Jun 30, 2001 5:13 am
Real name:

Re: Final Design

Post by DaveC » Mon Feb 01, 2010 10:15 pm

Hi Brian -

A nice looking design. Seems to have most everything you'll need at the outset.

Yeah, it's probably not the "final" design.. but it final for this stage... and that's a good start.

I'm in general agreement with Doug, that big windows have some value, although as Carl points out, there's also a liability. Implosions can spoil a whole afternoon....

So I tend to like nice tough pryex or even fused silica (but $$$ for that)... for the window, and a slab of leaded glass mounted outside for Xray control. A sacrificial piece on the interior, will keep most of the nasties away from the viewport.

I actually have a 5 way cross - same size as your dwg, and it is very useful for many types of experiments. Add in a autoclave type door, and you've got accessibilty and convenience.

We'll all be eager to see the finished product and experimental results.

Dave Cooper.

Post Reply