Jefferson Lab inaugurates upgraded CEBAF

Experimental hall D

On 2 May, the Thomas Jefferson National Accelerator Facility in Virginia, US, celebrated the completion of the 12 GeV CEBAF upgrade project. The $338 million upgrade has tripled CEBAF’s original operating energy and will allow, among other studies, more in-depth investigations of nuclear confinement. 

CEBAF (Continuous Electron Beam Accelerator Facility) provides high-quality beams of polarised electrons that allow physicists to extract information on the quark and gluon structure of nucleons.
The CEBAF accelerator started up in 1994 and originally delivered 4 GeV beams, which were later pushed to 6 GeV thanks to efficiencies in the machine’s design and extensive experience gained during operation. Previously, CEBAF operated as a pair of superconducting radio-frequency linear accelerators in a “racetrack” configuration, capable of delivering 6 GeV electron beams simultaneously to three experimental halls. In 2008 work began on a major upgrade project to double the maximum energy and add new
experimental setups.

The 12 GeV CEBAF upgrade project required 10 high-performance, superconducting radio-frequency cryomodules, doubling the capacity of the existing cryogenics plant, and the addition of eight superconducting magnets and other system upgrades. The upgrade also includes the construction of a new experimental area (“hall D”) for dedicated research on exotic mesons produced by energetic photons incident on a target. CEBAF’s newly energetic and precise beams will enable the first 3D views of the structure of protons and neutrons, the study of the origin of confinement in QCD, and the investigation of physics beyond the Standard Model by testing the theory’s completeness at low energies.