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In some cases it is necessary to make a brain operation, cutting several nerve tracts. In 1958 surgeons made this operation for the first time with an “atomic knife” – a proton beam that required no cutting into the brain. Usually such operation required weeks of preparation and many weeks of recovery. The atomic operation took about two hours; as soon as it was over, the patient walked off to a meal. He did not feel any pain and only said that he was tired from sitting in the same position for two hours. During the operation the patient was rotated from time to time so that the beam from synchrocyclotron could strike the brain at different angels. The surgeons directed the beam from another room, giving the patient instructions from time to time by the telephone.
The proton beam was 10 mm wide and 2 mm thick.