A device and procedure for measurements of the effective secondary emission coefficient

摘要

The design of the device and procedure of measuring the effective secondary emission coefficient gamma(eff) in glow discharges with a large-area cathode are described. The values of gamma(eff) and the density of the ion current on the cathode in the self-sustained and nonself-sustained (under the additional external injection of electrons) discharge burning modes are determined. It is shown that for the self-sustained burning mode of the basic discharge with a current of 30 A, the value gamma(eff) a parts per thousand 0.15, being in good agreement with both the theoretically calculated and known reference data. When the basic discharge occurs in the nonself-sustained mode, gamma(eff) = 0.08-0.12, depending on the discharge burning voltage, and the ion current density on the cathode surface is equal to 0.8-1.1 mA/cm(2), being a parts per thousand 10% lower than the value characteristic of the self-sustained discharge mode.