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: X-ray film detector
Date: Oct 03, 8:52 am
Poster: Richard Hull

On Oct 03, 8:52 am, Richard Hull wrote:

You are probably generating second order particles with the alpha particles bobarding the paper, plastics and foils.... Recoil protons, xrays, scattered electrons, etc. The Am241 puts out a potent alpha.

There are neutron emulsions as some of my books mention, but they rely mainly on proton recoil.

Try putting the source with the neutron goodie about 1"-2" from the film. This will now pretty much only see the neutrons alone as the mean free path for the charged recoil and scatter components in air is very short.

Richard Hull

>I am trying to use dental X-ray film as a detector for neutrons. (Yes I am a dentist by profession)
>I scavanged some Am 241 from some old smoke detectors to try and produce a neutron source.
>I used a layer of LiF over the alpha source then placed this over the X-ray film for a few hours.
>In fact I did a number of tests and all produced an exposure? I tried various combinations of layers of LiF Pb and B to try and tell if I was producing neutrons.
>The following are some combinations that were used:
>1. Am241 source on X-ray film (note: film is encased in paper covered with plastic)
>2. Am 241 LiF and Al foil on X-ray film
>3. Am 241 Lif and Al Foil Pb foil Boron then X-ray Film
>4. Am 241 on Pb foil on X-ray film.
>All arrangements produced an image on the film after 6 hours of exposure. The only noted difference was the films with a Pb foil between the source and film produced an image that was a little lighter than the others.
>I was trying to produce neutrons with the LiF and the alpha source, then fire them through the lead foil, then detect them with the boron and expose the film.
>The film is encased in carbon and hydrogen basically ( paper and plastic )
>I didn't expect to get images from all the films??
>What type of reaction am I getting with the Am 241 on the X-ray film alone? And why does this reaction appear to go through lead foil? Any suggestions or guesses as to what is happening here?
>What is the easiest way to detect neutrons using these materials?
>Thanks Al