We want a pure LHC-kill-beam thought experiment here
I really don't know what would happen if you put your head (or hand) into the LHC beam, and contra the article, the Anatoli Bugorski incident only gives us a vague sense of what would happen in the much more powerful LHC. So let's do a Fermi-style thought experiment. Also known as writing down a bunch of numbers and then guessing from that.
Once again, physicsmatt tackles the big questions on our behalf, this time regarding a mind-blowing hypothetical about the Large Hadron Collider.