Cornell physicists, led by Georg H. Hoffstaetter, Physics, and working with the United States Department of Energy’s Brookhaven National Laboratory (BNL), are constructing a new type of particle accelerator called CBETA at the Wilson Lab. It is a prototype for technology that will be used in a future electron-ion collider and which can be used over a wide area of accelerated beam applications, from materials science to medicine. CBETA can also be used for elementary particle experiments at Cornell.

CBETA will be a breakthrough in several ways. Leveraging multiple technologies already developed at Cornell, it will simultaneously recirculate multiple beams of very different energies. The electrons will make four accelerating passes around the accelerator, building up energy as they pass through a cryomodule with superconducting radio frequency accelerating structures. In four more passes, they will return their energy to the superconducting cavities that originally accelerated them—hence it is called an Energy Recovery Linac (ERL). While this method recycles energy, it also creates beams that are much more powerful. They are more tightly bound, can produce brighter and more coherent radiation, can have higher currents, and can produce higher luminosity in colliding-beam experiments.

CBETA harnesses the superior beam density of a linear accelerator while reducing energy waste and increasing the current. Reusing the same cavity significantly reduces the construction and operational costs and also means an accelerator that spans roughly a football field can fit into a single room.

CBETA will also be the first project in the history of accelerator physics to implement cutting-edge fixed-field alternating gradient magnet technology in an ERL. In the next several years, CBETA will develop into a powerhouse of accelerator physics with some of the most advanced accelerator technology on earth. When complete and expanded, it will be a critical resource to New York State and the nation, propelling science and economic development.

Dominant funding for CBETA comes from the New York State Energy Research and Development Authority (NYSERDA). NYSERDA emphasizes the energy savings that CBETA will provide by its use of energy recovery technology, its application of permanent magnets, and its particle acceleration by superconducting structures.