Interesting. I don't think I had ever heard the term cavity magnetron before today, but I was flipping channels and caught a part of a documentary on the History Channel here in the U.S. that mentioned this. The documentary was about inventions that came from war.

>You wanna know why the US became the most technologically advanced country in the world?
>
>Along with our selling the Harrier VSTOL techology to you lock, stock and barrel, this is enough to make me weep:
>
>http://news.bbc.co.uk/1/hi/sci/tech/6331897.stm