Working in the Proton Synchrotron tunnel to allow extra opening for the new m₄ beam in the South hall

The proton synchrotron was shut down for practically the whole of April 1964, from 26 March until 29 April. During this time, many changes were made to the beam layouts, especially in the North and South experimental halls, to prepare for the next series of experiments. To allow for the new m₄ beam in the South hall, an extra opening has been cut in the reinforced-concrete wall of the machine tunnel, and this was completed during the shut-down.