Current pressure characteristics of glow type discharges

Current (j) - pressure (p) characteristics of glow-type discharges are a basic element in a wide variety of advanced device and instrument configurations. Fundamental properties and modes, and how they are affected by various parameters, are deduced. Townsend-mechanisms are employed, within the uniform electric field approximation. Where possible, published coefficients are utilized to spot key features, critical points, types of non-linearities and useful bounds, affording physical insights and often obviating the necessity of extensive calculations. Using empirical expressions for Townsend\´s 1st coefficient, coupled with non-dimensionalization procedures, additional deep-seated characteristics are exhibited. Several j-p modes are delineated; j-levels, sensitivities, bandwidths, merit factors, etc., including methods of controlling them, are treated. An operating-parameter diagram, on which a variety of domains are traced, correlates qualitative/quantitative features and provides design selection bases. Variation of j with gap-spacing (g) is similar to that with p; the interpretation, however, is distinctly different. Where electrical relaxation constant time in which p,g change significantly, the solutions may be taken as dynamic; and distinct j-waveform responses to time-varying parameters are shown possible.