Chantier pose poutre béton précontrainte et tunnel ISR effets gerbe d'eau avec voiture et boue effets traces de pas dans la boue effets de nuages

The new concrete shielding roof (images 139-142.9.68) which was built over the top of the existing PS tunnel over the target zone from which beams were taken to the North and South experimental halls (see CERN COURIER vol. 8, page 178). This precaution was done to prepare for the radiation levels which had been generated as the intensity of the proton synchrotron had been increased.