Accelerator column

[George Schmermund]

Steve - Sounds good to me. I'd have done the same thing if I wasn't so lazy. Once again, I was only testing the parts and method of assembly.

[Dustinit]

I like this.
Looks like it could be directly coupled to the stages of a cw multiplier too.
RF acceleration might also be possible by extending each coupling a bit towards the source although the freq would probably be too high with such short stages.
Dustin

[ggombert]

Hi,
I was wondering if anyone had done anything more with the concept that George came up with for a low cost accelerator column since this thread was originally posted?

Questions that come to mind are:

-- The first stage would probably need a variable resistor to focus the beam; the rest of the elements could use fixed resistors (perhaps the 200 M ohm) that is mentioned in the original description.
-- Would the proposed assembly method allow 10-5 vacuum without any additional sealing (or would something like this be required)?
-- Would simple corona barrier be a smaller hole in the ½ inch coupling made with a piece of copper/brass and attached before the sections are assembled?
-- Of the many good ion sources described in the forum what would be the simplest to use with this sort of accelerator column?

This seems like too neat a simple concept not to at least try and carry the design a bit further to a working prototype.

Cheers,
Glenn

[John Futter]

Glen
Good questions
The simplest ion sources would be either Carl Willis;s HFRF driven one or Doug Coulters Microwave oven derived source. other possiblities include cold cathode penning type.

1x 10 e -5 Millibar should be very easy to get with what George has presented. Bear in mind that you would want to operate the tube an order of magnitude below this for best results (beam spreading due to neutrals).

A 50 l/s turbo would be heaps for this

and yes the top tube section is generally referred to as the Focus electrode

[ggombert]

Hi,
The attached file describes a simple ion source that is similar to what was used on the original Amateur Scientist article in 1971. It was built by a group of students that modeled what they built loosely based on that article. Would this type of design be suitable for use with the accelerator column discussed here or is something more sophisticated required?
Thanks,
Glenn

[John Futter]

Glenn
Yes will work albeit badly
if a permanent magnet was put around the glass tube then you have a cold cathode penning type which will produce around 100x as many ions as what you presented
Reading all of this especially the chapters on ion sources should put things in perspective
viewtopic.php?f=6&t=3115#p12625