Neutrons and Neutron Generators

This article was originally intended as a brief introduction to the article by Richard Hull on the Farnsworth/Hirsch “fusor.” However, as there has been some interest by a number of subscribers in neutron generators, I decided to provide a somewhat more lengthy tutorial on the reactions that produce neutrons, some practical applications of neutrons, and a few of the various types of devices that have or are being used to produce neutrons. Closer to home, my first major vacuum project (this was around 1968) was to be a neutron generator. It consisted of a 500 kV van de Graaff machine with a five-foot accelerator tube. I got to the point of producing an electron beam. Frankly, it was a bit wobbly and quite scary. That’s when I decided that plasma devices would be more fun.