Focusing and defocusing magnets for ISR

Two magnets (one of the focusing and one of the defocusing type) which were powered in series with the magnets in one ring of the ISR. Two others were in series with the other ring. The magnets were located in the Reference Unit Room and were used in monitoring and controlling the ISR magnetic fields. The computer (a Hewlett Packard 2114) used in the system can also be seen in the photographs.