Formation and transport of a bright electron beam for flash x-ray applications

Measurements have been carried out to characterize a 1 MeV, 1 to 5 kA field emitter diode and to determine the emittance of the electron beam generated. The diode was found to be approximately space charge limited, and the beam emittance at 300 to 500 A of collimated beam was measured at 30 ..pi.. to 70 ..pi.. mr-cm, depending on the emitter geometry. Simple confinement of the beam over a one meter distance also was demonstrated, using axial magnetic confining fields of less than one kilogauss.