Controlling electron beam parameters in a high-current diode with an exploding emission cathode

The electron beam duration in sources with an exploding cathode is known to be limited by low-voltage arc discharge ignition in the acceleratin.r gap due to the gap filling with a plasma. A sharp growth in the beam current takes place before the low-voltage discharge ignition. The current grows from amperes up to the short circuit current within approximately 10-6 s. The purpose of investigation was to increase the duration of high-current prearc current pick-up phase and to study the possibility of current control at this stage. Experiments on studying the effect of the distance between the beam axis and the axially positioned chamber walls on the duration of high-current stage were conducted. In the second series of experiments a study was made on the possibility of increasing the efficiency of electron beam transport via the anode hole. A coaxial plasma accelerator generating the directed plasma bunches was used as a cathode. High-current electron beams with approximately 20 kA current, approximately (20-30)x10-6 s duration were produced. The beams of approximately 10-4 s duration, approximately 103 A current, approximately 104 eV energy were obtained for the first time. It is shown that one can control the hign-current beam shaping initial moment, duration and current amplitude by regulating the anode plasma concentration