Temporal and spatial formation of the glow discharge in neon filled diode at 4 mbar pressure

The results of the investigation of the glow discharge time and space development in the neon-filled diode at 4 mbar are presented. The glow is of the diffusion type with saturation current value 0.2 mA. The temporal development of current and light intensity of the 585.2-nm line (originated from the negative glow) emitted perpendicularly on the diode axis from different parts of the diode, are registered. Electrically registered (by the oscilloscope), the total current through the diode reaches the saturation for 3 ms, which corresponds to the formative time delay. On the other hand, the value of the formative time delay estimated statistically from the series of 5000 breakdowns is 4.7 ms. The difference in formative time delays is associated with the pre-breakdown current growth in the gap. The prebreakdown current is registered measuring the emitted light from diode gap. The investigation of light shows the increase of excitation in the gap at least 1.25 ms before any significant current is registered (I<1 /spl mu/A). The negative glow appears in the diode gap and in the next a few milliseconds covers the cathode, which indicates the presence of the multiplication processes in diode. The stationary regime in the diode is established for about 10 ms. These results show the validity of the statistical approach in the breakdown time delay investigations and in the understanding the nature of the formative time delays.