Check out the current Image de jour to see a photo of Jon's really nice looking system, which is all set up in a neat cabinet with his vacuum pumps (i assume a mech backed diff pump) under what looks like a custom table top. Thw whole system has a nice "spic and span look to it, with mostly metal plumbing, still nice and shiney.
10e-7 Torr is several orders of magnitude lower what most amateurs run, especially with a demo fusor. Hey Jon, were the pipe joints brazed? The copper has a really nice look to it.
Such low vacuum really isn't needed for a demo fusor, as glass bell jars become a danger at higher voltages.
Also, some of the really nifty plasma effects occur between 100 and 1microns. You will see it all, from electron beams to bugle jets to changing colors to star rays. My Mark I system, a bell jar fusor, was just beginning to show some faint rays in star-mode at about 8 microns. Now I am working on my stainless chamber, and haven't ran the Mark I much in the past two months. Also, It seems I've been fighting some invisible leak recently, limiting me to 50 microns. I haven't really given much attention to fixing it yet, spending most of my time preparing for the Mark II's implementation, maybe later this month. I have all the materials needed now to assemble the chamber, all which cashed in at about $335. I have some machine work to do before I can begin welding the parts together. I look forward to a totally new vacuum system, one cleaner and more streamlined with diff pump capabililty.
Anyways, nice system Jon! Let us know what happens when you (hopefully soon) get those grids welded.
Adam Parker
Jon Rosenstiel's Demo Fusor
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Tom Dressel
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Re: Jon Rosenstiel's Demo Fusor
Jon's demo fusor looks great. It also looks like Jon knows how to take a great photo of his set up, with a neutral background, to elliminate distractions.
Tom Dressel
Tom Dressel
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guest
Re: Jon Rosenstiel's Demo Fusor
Jon, good job on a well built system ! I am in the process of building my own. I am currently in the vacuum chamber construction stage and have been concentrating on the vacuum pump to sphere connection. I noticed that you are using soldered copper pipe(or at least it appears so) for most of your plumbing. How well does this hold up ? I was also wondering if you could elaborate on this and post another photo of the lower area(pipe connections and connections to vacuum pump). Thanks in advance.
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Richard Hull
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Re: Jon Rosenstiel's Demo Fusor
I concure with Adam Parker.............
Really sweet and clean Jon. Great work!!
Any time you dip into the "fives" (10e-5 torr). you have a good clean system. More than clean enough for fusor work. Heck, the "fours" show good vac technique!
We look forward to your postings of your first pass experiences and impressions.
Like Adam said, be real careful about checking that bell jar for hot spots due to electron beam impacts.
Everyone here who has built something has had a much better looking finished product that anything I have done. I am glad to see stuff so pleasing to the eye. Meanwhile, I will endeavor to continue to supply my eyesores. (It's a dirty job, but someone's gotta' do it.)
Richard Hull
Really sweet and clean Jon. Great work!!
Any time you dip into the "fives" (10e-5 torr). you have a good clean system. More than clean enough for fusor work. Heck, the "fours" show good vac technique!
We look forward to your postings of your first pass experiences and impressions.
Like Adam said, be real careful about checking that bell jar for hot spots due to electron beam impacts.
Everyone here who has built something has had a much better looking finished product that anything I have done. I am glad to see stuff so pleasing to the eye. Meanwhile, I will endeavor to continue to supply my eyesores. (It's a dirty job, but someone's gotta' do it.)
Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Jon Rosenstiel
- Posts: 1494
- Joined: Thu Jun 28, 2001 1:30 am
- Real name: Jon Rosenstiel
- Location: Southern California
Re: Jon Rosenstiel's Demo Fusor
Thank you for the praise, so far it's been quite the project. More fun than I've had for who knows when!
I guess I don't have the new method of scientific notation down quite yet! What I am trying to say is that I reached 7 times 10 to the -5. (Close to 10 to the -4) Also, my gauge accuracy may be suspect, but I do know it is well below extinction.
The pipe joints were soldered with "lead free silver bearing solder", (plumbers solder), as recommended by Steve Hansen of The BellJar. I've had good success using this solder. I think the use of a diffusion pump covers up some my "poor" vacuum practice. Kind of a "brute force" approach to a vacuum. I know that with only my mechanical pump running I can't pull that great a vacuum. (Leybold Trivac D1.6B) I love it when the diffusion pump warms up, the vacuum drops like a brick!
I'll take another photo of the "guts" of the system. I cropped that part out of the photo I posted because it looked too "messy" down there!
I'll be sure to watch out for heating of the belljar walls. Say, how about this? I was thinking about making a stainless steel cylinder about one to one and one half inches smaller in outside diameter than the inside diameter of the belljar. The top of the cylinder would be covered with stainless steel also. In the center of the top would be about a 2 inch diameter hole and above that would be mounted at a 45 degree angle a stainless steel mirror. (for viewing). Do you guys think this would work for neutron production? Or would the stainless get much too hot for the good of the belljar?
Jon Rosenstiel
I guess I don't have the new method of scientific notation down quite yet! What I am trying to say is that I reached 7 times 10 to the -5. (Close to 10 to the -4) Also, my gauge accuracy may be suspect, but I do know it is well below extinction.
The pipe joints were soldered with "lead free silver bearing solder", (plumbers solder), as recommended by Steve Hansen of The BellJar. I've had good success using this solder. I think the use of a diffusion pump covers up some my "poor" vacuum practice. Kind of a "brute force" approach to a vacuum. I know that with only my mechanical pump running I can't pull that great a vacuum. (Leybold Trivac D1.6B) I love it when the diffusion pump warms up, the vacuum drops like a brick!
I'll take another photo of the "guts" of the system. I cropped that part out of the photo I posted because it looked too "messy" down there!
I'll be sure to watch out for heating of the belljar walls. Say, how about this? I was thinking about making a stainless steel cylinder about one to one and one half inches smaller in outside diameter than the inside diameter of the belljar. The top of the cylinder would be covered with stainless steel also. In the center of the top would be about a 2 inch diameter hole and above that would be mounted at a 45 degree angle a stainless steel mirror. (for viewing). Do you guys think this would work for neutron production? Or would the stainless get much too hot for the good of the belljar?
Jon Rosenstiel
Re: Jon Rosenstiel's Demo Fusor
Hi Jon,
Your idea for using a stainless steel shield around the outer grid sounds good. A large piece of metal could probably sink alot of heat, and I don't think it will endanger the bell jar at all, especially if it doesn't touch it anywhere. You'll want to clamp or connect the cylinder real well to your base plate. The mirror idea sounds tricky, but doable.
It's great to hear you're having "vacuum success". It's quite a rewarding feeling to nudge a system down bit by bit, all through long and hard work for the novice like myself, achieving new and deeper pressures.
As for Richard, while he may not always go for "pretty" his work is definately NOT an eyesore. I never got tired of looking at it back in the days before I started my own work and greedily took in the useful info with great alacrity.
I have included in the images section a shot of my Mk. I fusor at the time of its retirement from experimental work.
Adam Parker
Your idea for using a stainless steel shield around the outer grid sounds good. A large piece of metal could probably sink alot of heat, and I don't think it will endanger the bell jar at all, especially if it doesn't touch it anywhere. You'll want to clamp or connect the cylinder real well to your base plate. The mirror idea sounds tricky, but doable.
It's great to hear you're having "vacuum success". It's quite a rewarding feeling to nudge a system down bit by bit, all through long and hard work for the novice like myself, achieving new and deeper pressures.
As for Richard, while he may not always go for "pretty" his work is definately NOT an eyesore. I never got tired of looking at it back in the days before I started my own work and greedily took in the useful info with great alacrity.
I have included in the images section a shot of my Mk. I fusor at the time of its retirement from experimental work.
Adam Parker