The Propagation of Potential in Discharge Tubes

Abstract

The propagation of potential in a long discharge tube containing air was investigated as a function of pressure (0.017 to 0.24 mm Hg) and applied potential (74 to 171 kv). Impulsive potentials were applied to one end of the tube while the other end was grounded. By means of a high speed cathode-ray oscillograph, it was found that in the case of both positive and negative applied impulses a definite potential wave traversed the tube from the high voltage electrode to ground, immediately followed by a much faster return wave from ground back to the high voltage electrode. The wave velocity, voltage attenuation, wave form and energy carried in the wave front of the initial impulse were investigated and found, in general, to vary with both pressure and applied potential. The similarity of these results to the observations on the propagation of luminosity in long discharge tubes and in the lightning stroke are discussed. With the higher applied voltages the wave shows practically no observable distortion or attenuation so that the long discharge tube provides an excellent transmission line for many purposes.