A universal triode-based plasma device with controllable electrokinetic characteristics

Abstract

The electrokinetic parameters of a low-voltage beam discharge (LVBD) were experimentally investigated using a three-electrode configuration with a constricted discharge channel. The triode anode incorporates a central aperture, and the control electrode is positioned outside the main discharge region. Using a flat single-sided probe, we measured the spatial and energy characteristics of the highly anisotropic electron velocity distribution function in two discharge modes—contracted and diffuse. Current transport mechanisms were analyzed, and the conditions governing the transition between these modes were identified. In the diffuse mode, current transport is dominated by beam electrons. We demonstrate that, during the transition from the diffuse to the contracted mode, both the plasma parameters and the discharge current–voltage (I–V) characteristics change sharply. Thermal plasma electrons begin to play an active role in excitation, ionization, and current transport. As a result, the three-electrode LVBD can, when required, be used as a current stabilizer over the range of 0.2–10 A, a voltage stabilizer over 20–50 V, or a current amplifier with a gain factor of approximately 25.