Critical reading – Proving the Principle

As part of my preparations for interviewing Ray Haroldsen, one of the pioneers from the National Reactor Testing Station near Idaho Falls, Idaho, I have been reading a fascinating history of the Idaho National Engineering and Environmental Laboratory titled Proving the Principle. (The link takes you to a site where you can download all of the chapters of the book as PDF files.)

As I was reading it, I came across a statement that made me pause. It was so troubling that I had to send back some feedback immediately, even though the book was published in 1999 and there might not be anyone checking the feedback in-box anymore.

Here is the sentence that surprised me, especially considering the publisher and the site where the book is hosted:

“Scientists soon found that they could strip the electrons or neutrons from certain atoms and bombard other elements with them. They built great machines – atom smashers – to find out what would happen when they fired streams of neutrons into various elements at high speed.”

Atom smashers – also known as particle accelerators – are enormously complex and expensive devices that often include miles of copper tubes and consume vast quantities of electricity. They were favorite toys of the physicists of the 1930’s, but they were NEVER used to accelerate neutrons. Since neutrons have no charge, they do not respond to the magnetic fields used in particle accelerators.

If you want to find out what would happen if you fire streams of high speed neutrons at various elements, all you have to do is put certain isotopes that decay with alpha emission near certain other isotopes that break apart and release neutrons if hit by an alpha particle. For his ground breaking experiments in atomic structure and artificial radiation, Fermi used radon mixed with beryllium sealed in a glass tube that was only a few inches long, not an accelerator that required vast resources.

Another great source of neutrons is a fission reactor, but the physicists of the 1930’s did not yet know about those.

Of course, you can use a particle accelerator to speed up protons or alpha particles to hit targets that then release neutrons, but why bother when there is a FAR cheaper and easier way to do it?