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: X-ray penetration of fusor
Date: Nov 02, 1:09 pm
Poster: Richard Hull
On Nov 02, 1:09 pm, Richard Hull wrote:
I was deleting old e-mails and found an e-mail from early 99 when Scott Little was working on his fusor and we were in daily contact.
X-rays are the most serious radiation in any amateur fusor and will rise to be the predominant health risk long before the neutrons pose a genuine hazard.
Scott has many years of experience with x-ray detection instruments, having been employed in that area.
He supplied some data regarding pentetration of a standard .090 SS wall of a fusor for ever increasingly energetic X-radiation which I post below...........
I calculate the following attenuations for
your 0.090" SS walls:
Energy (keV) Fraction transmitted
Of course, this doesn't really tell you what the exposure rate will be but
it gives you some indication. Also, you need to remember that, at 40kV
example, only a very few of the x-rays produced have 40 keV of
energy....most are about half that in energy.
From the above it can be seen that X-ray shielding is not a real issue until 50-60kv is applied, which I don't think anyone has approached.
I have never quite hit 30kv on my best runs, but that is due to poor vacuum control. (dirty system). The glass port is a dangerous area to approach above 22KV and using the human eye to observe here is a big no-no as it is one of the most sensitive organs in the body to radiation.
Use a cheap B&W video camera to observe the poissor. I have never looked with my eye into fusor III since the low voltage test phase in Dec 1998. X-ray leaks around this area are the big problem with fusor operation from a radiation stand point. Point this region away from you and onlookers when running fusors.
- Re: X-ray penetration of fusor - Jim Lux Nov 03, 12:30 pm