COLLIDING BEAMS: PRESEhy STATUS; AtiD THE SLAC PROJECT*

The field of colliding-beam physics was born in 1958 with the start of construction of the first colliding-beam device by a Princeton-Stanford collaboration. This device, a 2 x 550 MeV electron-electron storage ring, yielded its first results on electron-electron scattering in 1963 and has since been dismantled. However, it spawned a host of more powerful offspring in Western Europe, the USSR, snd here in the U. S. The widespread interest inthesecolliding-beam devices is of course due to the new kinds of phenomena they can study in particle physics and to the enormous centerof-mass energies they can reach at much less cost than conventional accelerators (a 2 X 3 GeV electron ring is equivalent in center-of-mass energy to a 36,000 GeV accelerator beani hitting a stationary electron target; a 2 X 28 GeV proton ring like the ISR at CERN is equivalent to an 1800 GeV proton beam hitting a liquid hydrogen target; a 2 X 400 C&V proton ring which could be built at NAL is equivalent to a 340,000 GeV proton beam on a hydrogen target).