Impulse-Breakdown Characteristics of a High-Power Gas Switch Based on Graphene Cathode

Graphene has attracted great interest for its distinctive band structure and physical properties. Results from previous studies show that a graphene cathode can provide stable field emission and intense emission in a vacuum. In this paper, a graphene cathode was fabricated using chemical vapor deposition (CVD) on copper electrodes, and the breakdown of the cathode in a high-pressure gas was studied. A low-jitter, self-breakdown gas spark switch based on a graphene cathode is proposed in this paper. The impulse-breakdown characteristics of this switch in a quasi-uniform electric field were studied. When the gap length is 5 mm, and the gas pressure is 0.6 MPa, the average breakdown voltage (UBD) is nearly 85.9 kV, and the voltage jitter is only 3.2%; these values are much lower than those for pure copper cathodes and graphite cathodes. The graphene cathode is found to be a suitable choice for use as a high-power gas switch in applications requiring an intense emission source.