Creation of a firerod by a positive voltage step applied to an anode immersed in a weakly magnetized discharge plasma column

Postive voltage steps are applied to a plane electode immersed in a weakly magnetized discharge plasma column with its surface perpendicular to the magnetic field lines. Voltage steps of different amplitude are applied at various neutral gas pressures. If the amplitude of the voltage step and the neutral gas pressure are high enough, additional discharge occurs in front of the anode and a firerod is created. In this work, time development of the electron distribution function is measured using plane Langmuir probes, cylindrical Langmuir probes and emissive probes. The anode plasma electron population starts to form approximately 3 μs after the voltage step, and is formed in approximately 6–7 μs. The results obtained with the three different types of probes are compared, and found to be very similar.