A Russian scientist named Anatoli Bugorski was once hit in the head by the proton beam in a particle accelerator. He survived.
Bugorski was working as a researcher at the Institute for High Energy Physics in Protvino in 1978. At the time, he was working with the the largest Soviet particle accelerator at that time, the U-70 synchrotron. He was checking a malfunctioning piece of equipment when safety protocols failed, and he managed to accidentally stick his head in the path of the proton beam. According to his own report, he felt no pain but saw a flash brighter than a thousand suns. After the accident, the left half of his face swelled up and the skin began to peel. Having received a huge dose of radiation, he was not expected to survive. However, he made a full recovery and even completed his PhD. He is still alive today, and the only long term side effects seem to be deafness in his left ear, increased fatigue, occasional complex partial seizures and rare tonic-clonic seizures.