Nanoclusters and nanoscale voids as possible sources of increasing dark current in high-gradient vacuum breakdown

The potential barrier model considering an additional current that can lead to the high-gradient breakdowns in accelerating structures is proposed. An oscillatory resonance feature of field emission from a double-layer metal system with nanoscale coating shown. double was used for calculations density value. presence resonant properties nanometric revealed. increasing more than 5 times (for constant value electric strength E=5 GV/m) when not ideal copper surface nanoclusters on or voids near-surface layer observed.