Microwave discharge initiated by double laser spark in a supersonic airflow

Abstract

In this paper, we report the results of an experimental study of microwave (MW) discharge in the supersonic flow initiated by the laser spark and numerical simulation of multiple laser spark shockwave structures in airflow. The MW discharge initiation has been produced by single and double laser sparks. By using different spatial and temporal configuration of laser sparks in supersonic flow, we demonstrate the feasibility of an MW breakdown threshold decrease and control over shape and location of MW plasma. Calculation of laser spark shock wave structures shows good agreement with experimental shadow photographs both in the front shock wave diameter and its internal structure.