First experimental observation of plasma breakdown for detection of radioactive material using a gyrotron in real-time

A gaseous plasma avalanche phenomenon is one of candidates to discover a radioactivity in long-distance. A minimum lag time composed of mainly formative delay time and statistical delay time is essential to initiate the plasma volume discharge. Based on the delay time distribution, the existence of radioactive material is determined. In this paper, we present experimental results on the reduced delay time with radioactive source.