This disclosure is concerned with a process of and apparatus for producing relatively low energy electron beams through pulsed cold-cathode beam generation in a mode of operation involving an important intermediate region of a substantially linear depth-dose profile characteristic that reduces the sensitivity to possible voltage variations, and with improved triggering structures that significantly improve reliability and minimize erractic pulse genera- _ tion and missing pulses, thus particularly adapting the process and apparatus for such stringent applications as production-line steritization of surfaces, materials or workpieces passed by the apparatus.