Experimental Facilities: B Factory and PEP-II

The B Factory facility is pursuing a broad agenda of physics involving the heavy quark and heavy lepton sector. This facility is made up of two storage rings in the PEP-II facility, and a  detector, BaBar, to take advantage of the of the high-intensity collisions. The B Factory facility was dedicated on October 26, 1998 by Energy Secretary Bill Richardson.

PEP-II

The PEP-II facility consists of two independent storage rings, one located atop the other in the already existing PEP tunnel. The term "asymmetric" refers to the fact that the electron and positron energies in the two opposing rings are not equal.

• The high-energy ring (HER) stores a 9 GeV electron beam, an upgrade of the existing PEP ring. The support structure and magnets from the decommissioned PEP ring were reused. A state-of-the-art copper vacuum chamber and a new radio-frequency system capable of supporting a stored beam of high current were added.
• The low-energy ring (LER) stores 3.1 GeV positrons.

Electrons and positrons from the SLAC accelerator are extracted when they reach the correct energy and are then transported in dedicated bypass lines and injected into the PEP-II rings.

The beamlines and detector were commissioned in May 1999. In fact, the first event was seen on May 26, 1999 -- check out the Stanford Press Release.