Use of secondary-electron yields determined from breakdown data in cathode-fall models for Ar

We test the utility of recently published secondary-electron yields per ion for the prediction of operating voltages for abnormal cathode-fall discharges in Ar for normalized current densities 20 mA cm-2 Torr-2. The effective secondary-electron yields per ion derived from spatially-uniform field breakdown and low-current discharge data give much too small discharge voltages at the higher current densities. In contrast, published secondary-electron yields per ion derived from ion-beam data at high ion energies and brakdown data at low ion energies give abnormal cathode-fall voltages that are within the present uncertainty of the models and of experimental data for Cu cathodes.