New Brass Piping, plus updates

Current images of fusor efforts, components, etc. Try to continuously update from your name, a current photo using edit function. Title post with your name once only. Change image and text as needed. See first posting for details.
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John Beutz
Posts: 52
Joined: Fri Sep 02, 2016 6:35 pm
Real name: John Beutz
Location: Minnesota

New Brass Piping, plus updates

Post by John Beutz » Fri Sep 30, 2016 4:11 am

To minimize the possibility of leaks in the tubing between the pump and chamber, I replaced the tubing with brass fittings, inspired by the Oakland University demo fusor viewtopic.php?f=18&t=10731&p=71044&hili ... sor#p71044, detailed in their report: download/file.php?id=10487
brass.jpg
brass2.jpg
brass3.jpg
I integrated the ball valve into the line. (photo 3).

There was a definite improvement in plasma quality. At less than 1/4 maximum variac output and seconds of pumping, I got the same level of plasma as I was getting at max power and ten minutes of pumping before. It looked like this when first turned on:
first run.jpg
Eventually, after a cleaning, tightening of some threads, and at a higher voltage input, I got some very nice pictures.
nice1.jpg
nice2.jpg
Still only marginal improvements. Based on other image of similar demo fusors (such as the images on this post: viewtopic.php?f=18&t=7838), I don't think the vacuum could possibly be better than 1000 mtorr, and is probably much worse. More work is necessary. On future runs, I will probably try not using vacuum grease and/or replacing the teflon tape with Loctite 290.

-John
Attachments
nice3.jpg

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