Ion gun design

For the design and construction details of ion guns, necessary for more advanced designs and lower vacuums.
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Conrad Farnsworth
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Ion gun design

Post by Conrad Farnsworth » Wed Jan 19, 2011 6:15 am

Doodling within spanish class resulted in an ion gun that not only ionizes but accelerates (part of my future experiment) any comments/will it work?
EDIT: it may appear as though my chamber is just "open", i just never finished it, it is ment to be a closed system.
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Steven Sesselmann
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Re: Ion gun design

Post by Steven Sesselmann » Wed Jan 19, 2011 8:11 am

Conrad,

There is a whole forum dedicated to ion sources, and quite a few neat designs that have been made by the members of this forum. Here is one John and I made...

viewtopic.php?f=12&t=5013&hilit=starfire#p32321


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

Conrad Farnsworth
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Re: Ion gun design

Post by Conrad Farnsworth » Wed Jan 19, 2011 11:28 pm

Steven,
Thank you very much!
-Conrad

Conrad Farnsworth
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Re: Ion gun design

Post by Conrad Farnsworth » Mon Jan 24, 2011 3:18 am

Im just gonna put this here for reference. However, this is the latest design, based off of all 5 pages of the forum (Fostini's Gun).
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John Futter
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Re: Ion gun design

Post by John Futter » Mon Jan 24, 2011 8:01 am

Conrad

I'm having a lot of trouble getting what you are doing

for a start a pic that should take 20 seconds on dialup is taking 5 minutes

your next addition now takes 10 minutes
neither have much to do with ion guns

your's might be an inefficient one but it is not described in the litrature


please take time to compress or resize/ re-sample a simple drawing

there are quite a few here that are not on broadband

I suggest you search on google or whatever "ion gun" and read the papers.


Most ion guns that have a reasonable output incorporate a magnetic confinement to make the electrons circle to give max presentations to available ionisable atoms.

do some reading before another "ion gun" post

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Richard Hull
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Re: Ion gun design

Post by Richard Hull » Mon Jan 24, 2011 5:37 pm

Re-inventing the wheel is a fun effort if that is your goal. A quick look at the old standby "pigatron" will reduce ion gun development time and let you move on to the overall mission, whatever that is.

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
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Carl Willis
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Re: Ion gun design

Post by Carl Willis » Mon Jan 24, 2011 7:45 pm

Hi Conrad,

I think ion source development is a realm for much innovation and key to pushing the performance envelope with homebrew fusion apparatus.

I share the others' concern that without a fuller description of the drawing, it resists easy interpretation. Can you explain what aspects of your design are analogous to (or take inspiration) from Phil Fostini's source? Phil made a number of sources, but my recollection is that all were hot-cathode variants. Your idea seems to have the magnetron / Penning, cold-cathode, magnetic-trapping, flavor to it instead.

Your drawing seems to depict an electromagnet coil wound around the ion source nipple (or is that cooling water?). It's not clear what the intentions are in this design. The magnet could be intended for focusing the exiting ion beam, or for trapping electrons to improve the efficiency of the source (both results will obtain in practice, to varying degrees of utility depending on the setup's particulars).

A little bit of advice about ion sources: they get expensive unless you make a point of sticking with standard feedthroughs and fittings. Whatever the idea is, it will involve metal-insulator joints or couplings. Check out the ISI and Ceramaseal catalogs and use the parts there for inspiration, to help shape raw ideas into a practical parts list that will stay under budget.

-Carl
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Conrad Farnsworth
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Re: Ion gun design

Post by Conrad Farnsworth » Tue Jan 25, 2011 2:41 am

John, I have read every post (and everything surrounding it) dealing with non RF ion guns within the confines of the ion gun section. I have also had some help from another community member. As far as picture size goes, I've attached a compressed picture to this post, let me know if it works (at dialup speed it should take about 1.5 seconds)

Carl, the picture goes as follows. The top tube is the positive feedthrough, it is insulated using a ceramic rod, it will be JB welded inside of a hole drilled within a CF Flange the tube will also be JB welded on the inside where the rod goes. The rod is connected to a washer looking device behind the Deuterium feedthrough to help "push" the deturions. Next down is the deuterium feedthrough i havent quite decided which material to make the vacuum side out of, but it will probably be ceramic. Finally, is the - side of the ion gun. The outside of this will be made of the same ceramic as the + side BUT it'll be longer since it will run right past the washer. This ceramic will also be JB welded along with the metal rod connecting to the tube that the deturions go through. ignore the rest above and below it, I was just attempting to be correct when drawing both flanges. As for the coil around the nipple, the coil is for an electromagnet.

Richard- a pigatron sounds pretty interesting...but what I am doing here seems to be the least labor intensive for what I plan to do (I'll need 4). However, I will start out with one to test if it works.

All- I'd like to thank you all for your attention and constructive criticism!
-Conrad Farnsworth
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John Futter
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Re: Ion gun design

Post by John Futter » Tue Jan 25, 2011 6:51 am

Conrad

Much better in download speed around ten -fifteen seconds
Well now I understand a bit better what you are doing
you need to look up "cold cathode penning ion source:"

these are what we use at work on our ion implanters.
The magnetic field is to make the electrons take a circular path to maximise any potential hitting of gas atoms to ionise them.
Ion pumps work in exactly the same way except that titanium is used to sputter and trap the gas ions.

so reading on ion pumps will also help
pay particular attention to the cathode aperture and its relation to the extracting electrode (normally a cone with a hole in it for the ions to pass into your system

duoplasmatron and other ion guns are also close in operation albeit with differing potentials and complexity

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