Magnetic Priming of a Relativistic Magnetron

Magnetic priming [1] experiments performed on the UM/Titan relativistic magnetron (6-vane, -300kV, 5-10kA, 0.3-0.5 mus) have shown improvements in magnetron performance over baseline operation. In the current experimental setup, three, 4-cm long magnetic wires (Mu-Metal) are located within the cathode structure, centered beneath the emission region, and spaced 120 degrees apart. These wires produce magnetic perturbations with N/2 azimuthal-symmetry (for pi-mode in an N vane magnetron). Because of the close proximity of the priming structures to the cathode surface, the magnetic perturbations are strongest in the region where the electrons are emitted into the magnetron interaction space.