Introduction
The GEN (FEL Driver) injector uses a photocathode gun, much like the Polarized Source. The FEL source, however, operates at 350 keV and uses a green drive laser which does not produce polarized electrons.
The gun drive laser is an Nd:YLF mode locked laser operating at 527 nm and 37.425 MHz (1497 divided by 40). The pulse structure is controlled using a pair of Electro Optical Modulators.