The CPS improvements 1965-1973: An assessment

In 1965, plans were made to increase the beam intensity delivered by the CPS by a factor of ten or more. The first stage, involving a new power supply for the main magnet and more than doubling the cycle repetition rate, was completed in 1968. In the second stage, which is now essentially complete, the major items was the construction of an 800 MeV slow-cycling booster injector. Many other modifications were included. The Linac current had to be increased by an order of magnitude to supply the Booster, and the higher beam intensities required a more powerful RF accelerating system. Besides the 800 MeV injection elements, quadrupole lenses were installed to avoid longitudinal dilu­tion at transition, and multipoles to counteract instabilities. In addition, the chamber vacuum was improved by a factor of ten, shielding and radiation resistance increased where necessary, and beam-equipment interaction reduced. Adequate instrumentation and control facilities had to be provided, and the efficiency of fast and slow extraction systems improved. Perturbations due to various collective phenomena had to be overcome. The performance obtained during the first physics runs is reported.