Design and experimental study of Penning discharge plasma anode for high current pulsed electron beam source

摘要

The Penning discharge structure was designed to produce plasma anode used in a high current pulsed electron beams source. The cylindrical anode of diameter 80 mm and height 30 mm was powered by a pulse voltage of similar to 5 kV. The plasma discharge characteristics were investigated by means of oscilloscope, current sensor and digital camera. The results show that the plasma discharge goes through two main stages, a high-voltage, low-current stage and a high current discharge stage. There exists an anode voltage threshold to ignite the high current discharge. With the higher working pressure and magnetic field intensity, the Penning discharge operates more quickly and steadily. The time accuracy can be controlled under +/- 0.5 mu s The peak discharge current increases proportionally with the anode voltage. The HCPEB emissions were realized with the optimized parameters including working pressure 7 x 10(-2) Pa, anode voltage 5 kV, magnetic field 2000 Gauss and ballast resistor 200 Omega. (C) 2016 Elsevier Ltd. All rights reserved.