Proton Synchrotron Straight Section 51

An accelerating radio frequency cavity, part of the 10MHz system. The top, under the red hatch, contains the actual ferrite-loaded accelerating cavity, while the blue bottom section contains the power amplifier. Matthias Haase is busy with the calibration of the gap voltage.
At the left of the cavity, between the pole pieces of the bending magnet, a pick-up of the radial beam position control.