The Civil Construction subproject consists of modifications to existing buildings and utility systems to support the 12 GeV accelerator operations, an addition to the Central Helium Liquefier (CHL), including substations and cooling towers, and construction of a new experimental hall (Hall D) complex with utilities. The majority of the conventional facilities to support the 12 GeV accelerator operations are the utility upgrades of low-conductivity water (LCW) and power. The existing CHL Building will be expanded to house compressors for CHL #2.
The accelerator portion of the upgrade will be constructed on the framework of the existing CEBAF accelerator. A 12 GeV beam to Hall D and up to an 11 GeV beam is needed for Halls A, B, and C. To achieve this, the accelerator will be upgraded to 2.2 GeV/pass (1.1 GeV/linac) and the beam transport system upgraded and expanded. These upgrades will be made:
The CJ (CTEQ-Jefferson Lab) Collaboration studies the quark and gluon structure of the nucleon by performing global QCD fits of parton distribution functions (PDFs). These parametrize a vast array of data including deep-inelastic lepton-nucleon scattering, proton-proton collisions (lepton pair creation, W-boson and jet production), and other reactions, with particular focus on the large-x region.