Fusor Forums

We've heard plenty about Andrew Seltzmann's very impressive and very advanced Anode Layer Ion Source.

But I, a person with somewhat lesser abilties, am interested in building something a bit different. To be specific, I'm interested in a magnetron ion source (please forgive me if the ALIS isn't actually a magnetron source)

In particular, I'm interested in something that would give something more like a point or spot source of ions, and that would require minimal machining and less specialized materials.


I've been looking at the Penning Ion Source presented here: http://www.rapp-instruments.de/Beschleu ... source.htm. The main thing that bothers me is that it seems like it would sputter (and heat) the magnet into oblivion (in contrast to the Seltzmann source where the magnets are both well-heatsinked and away from the plasma.)


Does anybody have any thoughts on this source?

Rapp's work is well known here over the years and it is well done. First rate effort. However, you will notice the attention he paid to the waveguide cavity to avoid killing himself and the tuning slugs he included to make sure the energy was delivered where it was needed in the guide. A far safer but less powerful system is the link coupled vacuum tube setup shown. Carl Willis posted some years back on a ham radio transmitter link coupled ion source. Good, powerful ion guns or sources are major undertakings. This assumes you want milliamp beam energies. Kilowatt supplies are often demanded for milliamp ion sources.

Richard Hull

I'm talking about DC-only penning ion sources. Not a microwave magnetron.

Your mentioned specifically you were interested in magnetron ion sources. Then you mentioned the specific reference to the penning systems. A huge gulf is affixed between the two. Not being argumentative and sorry if there was a misunderstanding on my part.

We had a great discussion at 2019 HEAS related to functioning penning systems being developed by Dan Knapp. A first rate talk. He may offer suggestions to you if he chooses. His work with another scientist does not to use them as an ion source, though that is what they do...His talk was about doing fusion within then. Very interesting concept and a work in progress with proof of the doing.

Richard Hull

I think "magnetron" has sometimes been used specifically to refer to the microwave generating tube, and sometimes to various devices that use both electrostatics and magnetics such as my sputter magnetron gun, which is related to a penning ion source but does not use penning configuration.


I'm talking about a penning or Penning-like DC source.