Compteur d'oméga de Tcherenkov

The giant Cherenkov counter (25 volume) from Saclay which was then installed at the Omega spectrometer. Its size was dictated by the need to cover as much solid angle as possible from the large horizontal and vertical aperture of the spectrometer magnet. At each end there was a 'picket fence' of scintillation counters provided by the Glasgow group supported by the Daresbury Laboratory.