0.9 MeV microwave electron gun system for an FEL

Abstract A 0.9 MeV microwave electron gun system has been designed as a high-brightness injector for a free-electron laser system. The electron beam is generated by a one-and-a-half-cell S-band microwave cavity and transported through an achromatic magnetic system consisting of two bending magnets and a quadrupole magnet located between them. Simulations predict a peak current of more than 45 A, a normalized rms emittance of less than 2π mm mrad in any direction, and an energy spread of 26 keV at the end of the system. The microwave electron gun has been fabricated and is being tested. Manufacture of the magnetic bunching system is under way.