According with the movie below, no one who works there really knows:
I’ve been curious about this subject for some time, mostly because no one knows what happens. Every physician working there knows that micro black holes are highly improbable, but if the beam touches live matter, the results are unexpected (I got my fingers crossed for some kind of Altered States freaky stuff).
Yesterday, during my all night insomnia, I’ve found the case of a Soviet scientist that got struck from a synchrotron bean. A synchrotron is essentially similar to the LHC but less energetic.
The radiation absorbed by his head was in the region of 1000 gray. 5 gray worth of X-rays is generally considered fatal, but Bugorski survived and went on to complete his PhD (a proton beam moving near the speed of light has different characteristics from an X-ray!). The side of his face that was burned by the beam’s exit has not visibly aged in the years since the accident.