Upgrading CEBAF to 12 GeV

As originally constructed, the Continuous Electron Beam Accelerator Facility (CEBAF) was a 4 GeV cw 5-pass recirculating linac. It has subsequently been enhanced to 5.7 GeV. Developments in lattice QCD have indicated that an extending CEBAF to 12 GeV would provide a unique opportunity to understand quark confinement. Jefferson Lab plans to reach 12 GeV by adding ten new 100 MV cryomodules and supporting rf systems to the present machine configuration. The 2K helium plant will be doubled. The beam transport system´s capability will be doubled to 12 GeV with minimal replacement of components and with minimal saturation in the magnets. A new experimental hall, devoted to the quark confinement investigation, will be placed so that the beam transits one of the linacs 6 times (vs 5 times for the other linac). Beam emittances are degraded by synchrotron radiation such that the horizontal emittance of 1 nm-rad at 6 GeV increases to 7 nm-rad at 12 GeV. This paper discusses the issues listed above plus requirements for all systems and developmental opportunities presented by the project.