"Roman Pot" at intersection I2, ISR

"Roman pots" are stainless steel containers, which can be moved from outside the vacuum chamber towards the beam. They house detectors which are conveniently at atmospheric pressure and can still be brought close to the limit of the circulating beam, to detect particles emanating at very small angles from the intersection of two colliding beams. Eifionydd Jones was the inventor of this device, highly successful at the ISR and now used again at the TOTEM experiment at the LHC. This particular Roman Pot, with a thickness of 0.2 mm, was built in 1980 for experiment R210 in intersection I-2, in preparation for proton-antiproton collisions in 1981. See also 7501065.