AN INVESTIGATION ON SECONDARY EMISSION PROPERTIES OF IMPREGNATED BARIUM SCANDATE DISPENSER CATHODE

A scanning electron probe is used to study the secondary emission properties of the im-pregnated barium scandate dispenser cathode, the influence of the activation on the secondary emis-sion property, the secondary emission image and the secondary emission distribution over the surfaceof the cathode. At optimal activation, δ_m=3.56 (E_(pm)=700eV). The activation has a larger effect onδ when the activation temperature is higher than 1100℃. The distribution over the surface of thecathode is non-uniform. The half-peak width of the distribution curve over the surface is 0.4. Theexperimental phenomena are discussed in relation to surface analysis of the cathode. The theoreticallyderived binomial distribution curves over the surface fit much better with the experimental results.

An investigation on secondary emission properties of impregnated barium scandate dispenser cathode

A scanning electron probe is used to study the secondary emission properties of the impregnated barium scandate dispenser cathode, the influence of the activation on the secondary emission property, the secondary emission image and the secondary emission distribution over the surface of the cathode. At optimal activation, δ _m =3.56 (E _pm=700eV). The activation has a larger effect on δ when the activation temperature is higher than 1100 °C. The distribution over the surface of the cathode is non-uniform. The half-peak width of the distribution curve over the surface is 0.4. The experimental phenomena are discussed in relation to surface analysis of the cathode. The theoretically derived binomial distribution curves over the surface fit much better with the experimental results.