CEBAF Injector Upgrade
A significant portion of the experiments performed at Jefferson Lab require a polarized electron beam. A subset of these are parity violation experiments which have exceptionally stringent requirements on the quality of the electron beam. As the sign of the electron beam helicity reverses at the target of the experiment no other measurable quantity of the electron beam may change. This includes the beam intensity, polarization, position, angle, energy or spot size.
To ensure this beam quality, a significant effort is put into the main injector where the laser beam and electron photogun combine to produce the intended electron beam and the beam is chopped, bunched and accelerated to the final injector energy, all while maintaining a parity quality electron beam (PQB).