What has JLab done with SRF?

Built and operated the CEBAF...

When the Continuous Electron Beam Accelerator Facility (CEBAF) project began in the mid-1980s at what came to be called the Thomas Jefferson National Accelerator Facility (Jefferson Lab), there was an immediate need to gear up to meet challenges for implementing the then-novel SRF technology on which CEBAF was to be based. That gearing up involved a number of scientific and technological activities that have evolved and that continue in Newport News and elsewhere today.

The CEBAF was built to serve nuclear physics experimenters by giving them high-quality, continuous wave (CW) beams of electrons for probing the quark and gluon structure of nuclear matter. The beams reach energies of up to 6 GeV (billion electron volts) with a 12GeV upgrade in the works. They come from the CEBAF’s 7/8-mile, racetrack-shaped underground accelerator in which each “straightaway” contains an SRF linear accelerator, or linac. In the beginning, the CEBAF represented an order-of-magnitude increase in the scale of SRF accelerators, and today remains the world’s largest operating application of SRF.

In fact, the CEBAF was the first large-scale application of SRF anywhere. To apply SRF at that scale, the challenges were technological, industrial, and in some cases scientific. SRF was a newly developed technology, and reliable SRF components needed to be manufactured, processed, assembled, tested, and installed on a production basis. In some cases, subcomponents had to be researched and developed.

As a result, Jefferson Lab’s SRF R&D capabilities were born, together with some purpose-built production capabilities targeted on the task of building the CEBAF. These SRF capabilities were based in large part on the importation of people from the successful SRF R&D programs at Cornell University and Stanford. The test lab—a high-bay facility inherited from NASA by Jefferson Lab—was converted largely to SRF purposes.

For more than a decade, the CEBAF has been reliably serving nuclear and particle physics experimenters with SRF-accelerated beams of electrons having outstanding characteristics. Because the CEBAF’s scientific successes have led directly to a new generation of questions about the quark structure of nuclei, and because the CEBAF itself has performed so well, the 12 GeV upgrade that will double the CEBAF’s energy is a near-term component of the U.S. Department of Energy Office of Science’s road map, Facilities for the Future of Science: A Twenty Year Outlook