A dc cylindrical coaxial glow discharge with an inner grid anode has been studied. The region between the two electrodes is
seen dark, while a brightly glowing region forms inside the grid anode up to the center. The current-voltage characteristic
of a dc cylindrical glow discharge in nitrogen is similar to that of a normal glow discharge, while the normal glow discharge
voltage decreases with increasing pressure. The minimum plasma potentials are observed in the hollow cathode region due to
the accumulation of electrons at the back of the grid anode. At the center, some of the passed electrons are converged, so
their potential is decreased. These electrons have a sufficient time to be redistributed to form one group with a Maxwellian
electron energy distribution function. The electron temperature measured by electric probes varies from 1.6 to 3.6 eV, while
the plasma density varies from 3.9 × 1016 to 7 × 1013 m−3, depending on the discharge current and probe position. The plasma density increases as the electrons move radially from
the grid toward the central region, while their temperature decreases |
