A STUDY OF THE DARK-SPACE IONIZATION DYNAMICS IN A STATIONARY CYLINDRICAL HOLLOW-CATHODE DISCHARGE

A study of the ionization dynamics In the dark space of a stationary c ylindrical hollow-cathode discharge has been carried out. In a first-o rder approximation for the current densities, theoretical expressions have been obtained for the electric field and potential distributions. The dependence of the discharge current density on the forwards volta ge drop, argon being the used gas, has been measured under the followi ng experimental conditions: pressure 10-200 Pa, cathode radius 3-6 mm and current density 20-500 A m(-2). The thickness of the dark space ha s been determined from theoretical expressions and by a photographic m ethod, allowing us to discuss the ratio between the effective-number o i ionizations in the dark space and their total number. Under our expe rimental conditions, most of the ionizations are produced in the dark space. In this case, the dependence of the electric field on the catho de distance is nearly linear.