ФЕНОМЕНОЛОГІЧНИЙ ТА ГЕОМЕТРИЧНИЙ ОПИС ТЛІЮЧОГО РОЗРЯДУ З РІДКИМ КАТОДОМ (ВОДНИЙ РОЗЧИН МАГНІЙ ХЛОРИДУ) НИЗЬКОГО ТИСКУ

The article presents the results of a study of a glow discharge maintained between a liquid cathode (an aqueous solution of magnesium chloride) and a rod-shaped tungsten anode The inter electrode gap varied from 2 to 10 mm, the pressure from 0.675 to 1.65 Torr, and the discharge current from 40 to 100 mA. Three luminous regions, clearly distinguishable by the intensity of the emitted light, are visually distinguishable in the discharge gap: the anode glow, the cathode spot, and the positive column. No dark or faintly luminous bands are observed between or within these regions. The cathode spot is a uniformly glowing pink circle. Its diameter depends on the electrode gap and the discharge current. Based on the experimental results, a semi-empirical formula was derived that relates the diameter of the cathode spot to the length of the gap and the current. Under the experimental conditions described above, the positive column typically has a conical shape. However, at low currents, it assumes a bell-shaped form, and at higher currents, it becomes ellipsoidal. For a conical positive column, an increase in current density is observed in the direction from the cathode to the anode; it is determined by the angle between the cone projection line and the cathode plane (the cone tilt angle). A formula for calculating the degree of increase in current density is proposed. Based on the experimental results, a semi-empirical formula was derived that relates the cone inclination angle to the gap and current.