PBFA II applied B ion diode beam characteristics at high voltages

Summary form only given. An applied B-field ion diode has been operated at 10 MW on PBFA II to study high-voltage ion beam generation and transport physics. The radial focusing diode was powered at 25 TW with two conical self-magnetically-insulated transmission lines with and without plasma opening switches. The diode utilized a pair of B-field coils in disk cathode structures to produce a 3.5-T axial B-field in a 16-mm anode-cathode gap. The 15-cm-radius anode was configured with a 2-5-cm-tall ion emitting region. The 2.5-MA beam generated was transported toward the axis in a 13-cm-radius gas cell with a 2-μm-thick Mylar window and 5-torr argon gas fill. Four B-field coils in the anode structure adjusted the magnetic insulation along the anode surface so that the beam could be produced with nearly zero canonical angular momentum for any ion species or anode shape. Diagnostic measurements involving the voltage at the diode, diode and beam current, nuclear activation, witness plate damage, and Rutherford scattering images were obtained