It is an article I wrote with two French nuclear scientists several
years ago. I was working with them on measurements of cross
sections needed to design spallation sources of neutrons during
the last sabbatical (1995/96) and spent a lot of time learning about
what is described in the article. Unfortunately, the journal to which
it was submitted (American Scientist) did not want to publish it.
Feel free to share the article with your students.
Ludwik Kowalski