Self-bearing membrane exit window with the separate anode for sub-microsecond electron accelerator: Exit window for sub-microsecond e-accelerator

A vacuum electron diode of a sub-microsecond pulsed electron accelerator with various cooled air-water exit window designs were tested in single-pulse and high-repetition-rate modes. A well-known exit window construction with metal membrane and supporting grid was tested for 10⁴ electron beam pulses at 10 pps before crashing with vacuum failure. A design with a self-bearing anode-membrane demonstrated 10⁵ pulses durability without vacuum failure at 40 pps but accumulated damage like foil sag, overheating areas and surface discharge marks. The combined design of an exit window with an anode-grid and a self-bearing membrane demonstrated a lifetime of more than 10⁶ beam pulses at 40 pps operation.