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 29, 10:23 am
Poster: Richardd Hull

On Jan 29, 10:23 am, Richardd Hull wrote:

>To do this, I will need a SS plate with a 3" hole, and vacuum O rings etc to mount a 4" circular glass port. I'm inclined to just go for a 1" thick glass 8" in diameter. I realize that this will allow more neutrons to escape, but it seems that 10x times inconsequential is still pretty inconsequential.

100%, that is every neutron you produce WILL ESCAPE! with 3" thick solid SS walls virtually every neutron will still escape. You can't confine neutrons easily.

My point was, the bigger the glass, the more risk of E beam fracture and heating and definitely much more x-ray hazard exists. Very thin SS walls will stop 100% of all X-radiation you will produce. Glass will be a target and xray beam exit port.RH

>One problem is that the top 8" port does have an O ring channel, but the side one is just machined flat, I presume to mate to an O ring on the other side. This is where I would put the glass, using the top for the feedthrough.

A far better idea. use the top for the HV feed through and inner grid support. RH
>It seems likely that this will not seal even with a flat gasket. So, maybe I do need a circular plate with an O ring channel and a 3" port. Where might I get such an animal? Go to a machine shop and get it custom made? (Sounds like $300-$500 or worse, but if I have to....) Do you know someone who could make it to spec in a cheaper part of the country and ship to me?


Go to a good scrap yard. Get a suitable sized SS plate of metal. Why not leave it square and just bore holes as needed on a common drill press? Use a 3.3" commonly avaialble conflat flange system from there and the work can be done on a tiny 4" lathe from that point. Got any friends with small lathes? There are many ways to skin the cat if a good deal of forethought is given. However if beauty, elegance and style are demanded in the finished product, get out your wallet. If it is functionality your after put on the ole thinking cap and discover the known extant myriad of work-arounds involving more or less workable solutions. RH

>I got a much higher quotation, closer to $300 (this is Boston, not a more reasonable place price-wise). It was cheaper to pay the $150 deposit on a bottle, then $150 for the deuterium, and get the $150 back (eventually). Also, they wanted another $50 to ship from NJ.

Good grief! How many liters were in the bottle quoted? I have squandered my deuterium in the beginning and got a 20 liter cylinder (cylinder is mine to throw in the trash in the end). Now, with good technique and half my gas gone, I have enough left in this bottle for years more work. It is about 2" in diameter and 12" long and weighs about 2lbs. RH

>If I set up a mirror, will X-ray's reflect too, like light? I realize neutrons will penetrate.

A mirror is fine, (x-rays will be absorbed), but you may have to arrange a telescope or modified binocular to be able to see the inner grid well and clearly. You could also record on video with the lens zoomed in and manually focused. Never use auto focus for scientific work. RH
>>Richard Hull