High repetitive switching of parallel micro-plasma spark gaps

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Summary form only given. Micro-plasma high-pressure spark gaps have been investigated for the generation of ultra wideband (UWB) microwave pulses. Such micro-plasma spark gaps are characterized by sub-ns current rise-times and high peak power output in short impulses. A repetition rate of 1 MHz is demonstrated by a single micro-plasma spark gap at the Pohang Accelerator Laboratory, Pohang, South Korea. For the MHz repetition rates the peak power of such short impulses at a resistive load, generated by a single spark gap system, is limited due its relatively low breakdown voltage. In order to overcome this problem it was proposed to replace the single micro-spark gap by an array of parallel operating multiple micro-spark gaps. The non-synchronized operation of multiple micro-spark gaps showed an increase in the breakdown voltage by enhanced recovery time, but at the cost of reduced repetition rate of each micro-spark gap in the array system. Therefore, results are presented from experiments with two micro-plasma spark gaps. The emphasis of the experiments in the repetitive mode was on the optimization of the following parameters: The coupling effect between the two micro-plasma spark gaps, the operating parameters of the charging system, such as resistance and capacitance, as well as those of micro-plasma spark gaps in the array system. These experiments were dedicated to improve the repetition rate, the peak power as well as the average power of the output impulses. Finally, results are reported from experiments of switching four micro-plasma spark gaps in parallel. Different configurations of the four gaps - array system are studied with respect to optimize the operating parameters and to improve the coupling. In conclusion, breakdown voltage/current waveforms of each micro-plasma spark gap and their re-reproducibility in the array system are presented.