Since its completion at the end of 1959 the CERN PS has been the object of numerous improvements to increase its efficiency, flexibility of use and ease of operation. One of the latest of these is a new quadrupole focusing magnet, adjustment between the coils of one of the ring magnets of the accelerator. Designed and constructed in the PS Division, this lens is one of 50 which control the spread of the beam immediately after its injection into the synchrotron. At this energy, they replace the 20 much larger quadrupoles of more conventional design, one of which is seen on the left of the photograph.