Bugorski was a researcher at the Institute for High Energy Physics in Protvino. Specifically he worked with the Soviet particle accelerator the synchrotron U-70. On July 13, 1978, Bugorski was checking a malfunctioning piece of equipment. As he was leaning over the piece of equipment he stuck his head through the part of the accelerator that the proton beam was running through. Supposedly, he saw a flash that was "brighter than a thousand suns" at this point. Interestingly, he did not feel any pain when this happened.
The beam itself measured 2000 gray as it entered Bugorski's skull and about 3000 gray when it exited on the other side. A "gray" is an SI unit of energy absorbed from ionizing radiation. One gray is equal to the absorption of one joule of radiation energy by one kilogram of matter. An example where this is commonly used is in X-rays. For reference, absorption of over 5 grays at any time usually leads to death within 14 days. However, no one before had ever experienced radiation in the form of a proton beam moving at about the speed of light.
As you can see from the picture, the beam entered the back of Bugorski's head and came out around his nose. Shortly after this happened, Bugorski's left half of his face swelled up beyond recognition. He was taken to the hospital and studied as this was something that had never been seen before and so they closely monitored him thereafter, fully expecting him to die within a few days at most.
Although the skin on the part of his face and back of his head where the beam hit eventually peeled off over the next few days, Bugorski did not die as they thought he would. The beam also burned through his skull and brain tissue along with the afore mentioned skin. However, ultimately he came through it all surprisingly well.
Despite the beam going through his brain, his intellectual capacity remained the same as before. The few negative health drawbacks he did experience were not life threatening either. He lost the hearing in his left ear and experienced a constant unpleasant noise in that ear from then on. The left half of his face slowly became paralyzed over the course of the next two years. He also gets significantly more fatigued with mental work, though he did go on to get his PhD after this incident. The remaining side effects were occasional absence seizures and later tonic-clonic seizures, though these didn't show up right away.
"Ra-di-a-tion. You hear the most outrageous lies about it. Half-baked goggle-box do-gooders telling everybody it's bad for you. Pernicious nonsense."