Making My First Successful Film

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.
ian_krase
Posts: 348
Joined: Mon Nov 28, 2016 7:48 am
Real name: Ian Krase

Making My First Successful Film

Post by ian_krase » Fri Feb 10, 2017 7:51 am

The glow discharge is actually pinker/paler than it looks here, and the parasitic glow around the periphery of the cathode shell is significantly dimmer than it looks in the picture. The cathode is copper sheet. Pressure is about 400 millitorr.

Yield after several hours was an oxide film that could be scratched off with metal tools but not with a fingernail or paper towel, despite the glass substrate being utterly filthy.
IMG_20170122_001441.jpg

Andrew Seltzman
Posts: 674
Joined: Mon Feb 02, 2004 1:02 am
Real name: Andrew Seltzman
Contact:

Re: Making My First Successful Film

Post by Andrew Seltzman » Fri Feb 10, 2017 8:33 am

Nice, what type of plasma/ion source is that?
Andrew Seltzman
www.rtftechnologies.org

ian_krase
Posts: 348
Joined: Mon Nov 28, 2016 7:48 am
Real name: Ian Krase

Re: Making My First Successful Film

Post by ian_krase » Fri Feb 10, 2017 9:24 am

It's a planar magnetron.


A small stack of neodymium ring magnets are placed around a top-hat-shaped steel core, which also has an O-ring groove and the two cooling water tubes (1/8 inch refrigeration tubing). A copper pipe cap (w/ thinned end and soldered on tapped ears) is slipped over and screwed down, compressing the O-ring. A cathode plate is then bolted to the top. Copper is currently used, but I intend to try silver since it's cheap.

Cooling water is supplied by a large 30ml syringe and a yogurt tub full of water; the low power of this system means that very little water is actually needed but it can't be allowed to go dry.

Gas is air, as you could probably tell. I intend to use argon, but don't have a cylinder or regulator yet.

ian_krase
Posts: 348
Joined: Mon Nov 28, 2016 7:48 am
Real name: Ian Krase

Re: Making My First Successful Film

Post by ian_krase » Thu Feb 16, 2017 6:37 am

I managed to hit a jackpot: Found a tested industry-grade pump (Pfeiffer Duo 2.5) at a low price on Ebay. I can get to 7 millitorr, and could likely get lower if my Pirani gauge wasn't leaking. Plus it has a gas ballast, has actual high-conductance KF input ports, and doesn't feel like it's going to burn up / wear out if run for an hour.




I also got a valve.

With this arrangement, I can actually see the green copper plasma. Sadly this is not photographable.
Attachments
IMG_20170215_213306.jpg
IMG_20170215_214448.jpg
IMG_20170215_214500.jpg

User avatar
Dennis P Brown
Posts: 1346
Joined: Sun May 20, 2012 2:46 pm
Real name: Dennis P Brown
Location: Glen Arm, MD

Re: Making My First Successful Film

Post by Dennis P Brown » Thu Feb 16, 2017 12:02 pm

Congrat's! I too have scored a number of good two stage vacuum pumps on e-bay and I am glad you did! Deals come and go; so keep this in mind when looking for a high vac system and be patient (turbo or DP. They do occur! Ion gauges are often cheap and some tubes come with fittings! Never buy unless they provide a money back return policy - if not, don't waste your money. Deals will appear again.)

I assume you cleaned and then added new oil to the pump? If not, you should do so. Also assume the old oil and surfaces in the pump has been contaminated with a possible toxic or carcinogen so gloves are important. Waste oil needs to be disposed of in accordance with all local laws. (I use a local gas-station recycle tank (with their permission, of course; I assume you did replace the oil and followed good practices but I am just playing it safe.)

ian_krase
Posts: 348
Joined: Mon Nov 28, 2016 7:48 am
Real name: Ian Krase

Re: Making My First Successful Film

Post by ian_krase » Sat Feb 18, 2017 6:16 am

I drained the pump (foul-smelling, dark, almost greenish thick oil) and filled it, flushed it, and then filled it again. Results are what you see on the gauge.

User avatar
Richard Hull
Site Admin
Posts: 10512
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: Making My First Successful Film

Post by Richard Hull » Sun Feb 19, 2017 2:48 am

6 millitorr is about the very best a really good mechanical pump can do!! What's the beef? A good pump down for a moderate foreline mechanical pump at the head is often 10 millitor! Move on, your pump is fabulous and I doubt your gauge is leaking.

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
Retired now...Doing only what I want and not what I should...every day is a saturday.

ian_krase
Posts: 348
Joined: Mon Nov 28, 2016 7:48 am
Real name: Ian Krase

Re: Making My First Successful Film

Post by ian_krase » Sun Feb 19, 2017 3:31 am

I know my gauge is leaking because it responds to dust-off. It's an uncommon pirani and piezo combo, meant for loadlocks and other things that really really care about pressure mechanical force. The piezo sensor is joined with a mildly silly o-ring seal that has a slow leak.


Yeah, it's time for diffusion - or more likely, for inert gas backfilling to around 100 mtorr.

ian_krase
Posts: 348
Joined: Mon Nov 28, 2016 7:48 am
Real name: Ian Krase

Re: Making My First Successful Film

Post by ian_krase » Thu Feb 23, 2017 3:38 am

Today, I finally got my hands on enough KF16 clamps (hooray for living within walking distance of Duniway Stockroom!) to attach my chamber and my convectron at the same time.

Then I was a bit confused as to why I couldn't get below about 80 microns.

Turned out my spark plug feedthrough was leaking around the center pin. Conveniently, the entire top of my vacuum chamber is metal and insulated (via the glass walls) from the bottom. So I just blanked it off and moved the wire.

Result was successfully extinguishing the glow, and just before that, it was white rather than pink/violet (which the photo as usual doesn't capture very well)


I am going to come up with a better feedthrough.
Attachments
IMG_20170222_184824.jpg

User avatar
Dennis P Brown
Posts: 1346
Joined: Sun May 20, 2012 2:46 pm
Real name: Dennis P Brown
Location: Glen Arm, MD

Re: Making My First Successful Film

Post by Dennis P Brown » Thu Feb 23, 2017 10:41 am

Excellent. That is a nice setup you have constructed.

Post Reply