Helical resistive focusing and acceleration.

For the design and construction details of ion guns, necessary for more advanced designs and lower vacuums.
Post Reply
User avatar
Richard Hull
Moderator
Posts: 14992
Joined: Fri Jun 15, 2001 9:44 am
Real name: Richard Hull

Helical resistive focusing and acceleration.

Post by Richard Hull »

As I am an observer at this moment, I might offer a really slick tip based on what these old eyes have seen in the past.

One of the neatest tricks and slickest ways to keep whatever beam you have accelerated and focused might best be accomplished using a helix of resitive paint painted from the gun output port (and connected to it) all along the INSIDE of the glass tube right up to, and connected to, the target!

Think about it.

The the key factor is to make the threaded helical line's total resistance such that it can handle the full acceleration voltage. Most such helices would need to be at least a gigohm. One would have to make a jig up to paint the helix inside of the tube. The distance of the helix to center line would be critical. The net effect is even and guaranteed voltage and field distribution from gun to target. The target should be surrounded with and connected to, an aquadag coating of graphite or silver paint inside the tube that the helix terminates in.

Tektronix and other premiere scope manufacturers used to do this helix trick in all of their super CRTs from the E-gun to the anode aquadag.

Super smooth gradients and warrants no arcing in tube.

Most such "ink lines" are made from a slurry of india ink of variable composition.

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
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Post Reply

Return to “Ion Gun Design and Construction (& FAQs)”