[Y]ou can have two... main types of radiation, which are ionizing, or non-ionizing. - Suzie Sheehy

That's only one particle accelerator. There are actually over 26,000 of them in the world.

[I]n cancer therapy usually you like to direct a dose of radiation exactly where you'd like it, so in this case... a child with a spine that needs irradiating. They've had a tumor removed from the base of the skull and they need to irradiate the spine in order to stop the cancer spreading down the spine... With... usual X-ray radiotherapy the dose distribution there is the best that we can do using all modern techniques. You can see that underneath the spine in... the stomach area there is quite a lot of radiation dose that we might not want...

[Y]ou may have seen... when the LHC was in the news, diagrams that look a little bit like this. These are called s after the famous physicist, Richard Feynman... [W]hat... most of my colleagues in particle physics do, is they take this [full Standard Model] equation, they figure out which particle's interacting and how: what's coming in, what coming out. They do twenty-one pages of calculations, and they come out with a number that is the probability of that interaction happening... [D]epending on which particles go in, you choose a different term that corresponds to those, and which particle comes out, you choose a different term that corresponds to those. Turn the handle and you get your result out the other end. I just taught you quantum field theory in about 2 seconds.