X-rays and microwave RF power from high voltage laboratory sparks

Abstract

Lightning involves high energy processes that still are not well understood. In the laboratory voltages pulses are used to produce long sparks allowing the production of energetic radiation. In this paper X-rays emitted by long sparks in air are simultaneously measured with the RF power radiation at ¿2.4 GHz. The experiment showed that RF power systematically peaks at the time of the X-rays generation (in the measurement time scale). Sparks presents peaks of RF radiation before the breakdown of the gap. The peaks are related to the applied voltage to the gap. RF peaks are also detected in discharges without breakdown. Cases where X-rays are detected present higher RF peak power. The results indicate that at some stage of the discharge before the breakdown electrons are very fast accelerating letting in some cases to produce X-rays. Microwave radiation and X-rays may come from the same process.