Question: Where does the radiation for your machine come from?

Paul Booker answered on 10 Mar 2015:

The only way to produce radiation is by accelerating or decelerating a charged particle. So what we do is accelerate electrons to high speeds then put a thin bit of metal in the way. When the electrons crash into the metal, they slow down and release energy as X-rays!

We do it this way because that means the machine is either on or off, so we don’t have to worry about radiation being present at other times and we can control it better.