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

The design of the device and procedure of measuring the effective secondary emission coefficient γeff in glow discharges with a large-area cathode are described. The values of γeff 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 γeff ≈ 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, γeff = 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/cm2, being ≈10% lower than the value characteristic of the self-sustained discharge mode.