"STARFIRE" Sesselmann-Hendron Ion Source Published

For the design and construction details of ion guns, necessary for more advanced designs and lower vacuums.
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Steven Sesselmann
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"STARFIRE" Sesselmann-Hendron Ion Source Published

Post by Steven Sesselmann » Sun May 10, 2009 11:05 am

"STARFIRE" is the ion Source that John Hendron and I developed two years ago when we both needed a powerful ion source for our respective fusion ideas.

As John lives in Nothern Ireland and I live in Australia, the cooperation was purely by email and phone, but resulted in a good friendship between us.

After we had developed the basic design, which was based on an earlier prototype that John had made, I built 5 of the ion sources and sent two of them to John (see attached images).

We applied for a patent with WIPO, and it has just been published here;

WIPO PATENT SEARCH

The ion source is a low tech. filament based source, but very robust, and capable of a substantial ion current. Allthough we have successfully used the Starfire ion source on the STAR fusion reactor, we still need to make accurate measurements and collect data on the performace of the ion source on it's own.

Steven

Bee Research

Pict 1:
Ion source with KF25 to KF16 glass nipple

Pict 2:
The guts of the ion gun, with Macor machined ceramic sleeves, tungsten magnetron filament and tungsten ring.

Pict 3:
The tungsten filament from a magnetron fitted into the ceramic holder (note the gas entry point is through the annular support at the bottom of the spiral filament)

Pict 4:
The two ion sources that were shipped to Ireland.
Attachments
Case.jpg
Case.jpg (868.49 KiB) Viewed 3243 times
filament.jpg
filament.jpg (839.46 KiB) Viewed 3243 times
Inside.jpg
Inside.jpg (366.39 KiB) Viewed 3243 times
gun.jpg
gun.jpg (667 KiB) Viewed 3243 times
http://www.gammaspectacular.com - Gamma Spectrometry Systems
https://www.researchgate.net/profile/Steven_Sesselmann - Various papers and patents on RG

MarkS
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Re: "STARFIRE" Sesselmann-Hendron Ion Source Published

Post by MarkS » Mon May 11, 2009 12:34 am

As a note to others, the first few times I tried to read the patent, there was a server error. You may have to refresh a few times to actually get the link to work.

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Alexi
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Re: "STARFIRE" Sesselmann-Hendron Ion Source Published

Post by Alexi » Thu May 14, 2009 5:14 am

Steven,

Could you explain how ions get extracted from your ion gun?
I am curious because it looks like almost all positive ions will be attracted to the negative 1000V filament (which is much closer to them then negative grid/reaction chamber), and will be neutralized there.

Cheers,
Alex.

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Steven Sesselmann
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Re: "STARFIRE" Sesselmann-Hendron Ion Source Published

Post by Steven Sesselmann » Thu May 14, 2009 5:31 am

Alex,

You are quite right, there is no extractor on this ion gun, as it was designed to be used directly onto a fusion reactor with a cathode of lower potential than the filament.

If you wanted to use this ion gun as a typical ion implantation device, you would need to add a further extractor stage, which could simply be a NW16 nipple at -2 to -3 Kv.

On the following youtube video you can see some close ups of the ion gun, when it was used on the STAR reactor.

This was an interesting experiment, because the cathode was immersed in oil with the PSU switched off, and the cathode remained in a state of negative charge after the PSU was switched off.

http://www.youtube.com/watch?v=t7SWLCbRqvs

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

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