The S91 experiment (Lundby) in the South Hall

Adjustments being made to the detection system of experiment S91 which was to study the scattering of kaons and antiprotons on protons. The experiment was at the time taking data at energies up to 5 GeV and would later extend the investigation to higher energies. In the picture can be seen the two arms of the detector, coming out from the target position, each with a large C magnet, wire spark chambers and counters on-line to a computer.