Microwave Generation in Atmospheric Air

Two sets of experiments are described. In the first set, the ultraviolet (UV) radiation created by the spark channel is passing through the wire mesh to illuminate the structure in the resonant cavity. The UV radiation creates many radiation lines in the photoionized plasma. The current flowing in the resonant cavity is also measured. The radiations exiting the cavity are compared with the data obtained in the atomic hydrogen maser. In the second set of experiments, the spark channel discharges are formed inside the resonant cavity. When the resonant cavity was tuned to 1 GHz, the objective is to learn why the system gives almost the single 1 GHz radiation line at the output under certain conditions. The study indicates that the basic mechanism of microwave generation in atmospheric air is the microwave amplification by the stimulated emission of radiation.