View of part of the DORIS electron/positron storage ring at the DESY particle physics laboratory, Hamburg. Rebuilt in 1981/82 and known as DORIS II, the ring accelerates electrons and positrons in opposite directions through the same beam tube. Experiments take place at two inter- action regions. The photograph shows part of the Doris beam as it goes around a corner, with the blue magnets bending the particles. As the high- energy electrons & positrons are bent, they give off synchrotron radiation, and this is carried by the fan of beams at left to a special laboratory (known as Hasylab) which uses the radiation for non-particle physics studies. (May 1984)