Studies of plasma production in a linear device with plane LaB6 cathode and hollow anode

A plane circular LaB6 cathode and a hollow anode are used for the arc discharge plasma production in a newly developed linear plasma device with the axially symmetric magnetic field. The cathode is heated by radiation from a graphite foil flat spiral. A separately powered magnetic coil located around the plasma source is used to vary the radial distance between the outermost magnetic field line from the cathode and the inner anode surface. The discharge geometry defines distinct operational modes: partially direct discharge and magnetic insulation. The magnetic field in the source can be varied from 0 to 2.4 kG while preserving the chosen field geometry, with the discharge voltage and current depending on the particular mode. A hydrogen plasma stream with a density of up to 1·1013 cm−3 and a diameter of about 4 cm is produced. The discharge characteristics and the plasma parameters do not change significantly between the two modes and in a relatively broad range of magnetic fields.