Fusion Message Board

In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.

Subject: Re: Novice Questions
Date: Jan 28, 8:27 pm
Poster: Richard Hester

On Jan 28, 8:27 pm, Richard Hester wrote:

The original spark plug post from Richard Hull may have gone missing in the latest housekeeping purge of old messages. Anyway, the plug you need is the AC44XLS, which has an especially long business end. If my memory serves me well, Mr. Hull prepared the plug by cutting off the threads with a hacksaw, neatened up the remaining metal in a lathe, and brazed the result to a flange.

It sounds like your chamber has ASA flanges from your description. You can check by visiting the KJ Lesker web site and looking at their descriptions and drawings. Maybe you can find some used flanges on the cheap, but another alternative might be to throw together some blankoff plates out of aluminum or SS sheet. The only real machining required would be an o-ring groove, if you are careful about drilling the bolt holes.
As others have already said, it is a good idea not to have the view port any larger than necessary, as it is a prime egress point for
X rays. If you bore a hole in one of your blankoff plates with the proper ring of blind threaded holes, you could use a KF-style view port with a bulkhead clamp. The going rate for a new KF25 view port is about $85, probably cheaper used if you can find one. The bigger ones are about $10 more expensive. Using a mirror to view the discharge is not a bad idea, as it will reflect the light but not the nasty stuff. Point the window down, so only the earthworms get x-rayed. Others use a video camera to view the discharge.