Performance of the CEA as an e+e- Storage Ring

The Cambridge Electron Accelerator (CEA) has been devoted solely to electron-positron colliding-beam physics since 1970. By early 1972 an operational system had been developed with a peak luminosity of 2 × 1028cm-2sec-1. An experiment observing e+e- , γγ, μ+ μ-, and hadron events was then completed at a beam energy of 2 + 2 GeV and an integrated luminosity of 1.12 x 1034cm-2. Since then, many improvements have been made to increase the average luminosity and to permit operation at higher energy. A cryogenic pumping system has been installed close to the interaction region resulting in a significant pressure drop and reduction in background in the luminosity counters. A final experiment is now in progress at a center-of-mass energy of 2.5 + 2.5 GeV, after which the colliding beam physics program will be terminated because higher luminosity is available from the Stanford storage ring SPEAR.