The purpose of this experiment is to maintain a stable plasmoid ( a ball lightning ) at one atmosphere in a spherical glass vessel. This experiment uses a kind of electronic trigger which is the GMR v1.0 ( Graphite Microwave Resonator ) placed in a microwave oven working at 2.45 GHz. A magnetron is compact, has a light weight ( compared to a HV transformer with the same output power ) and it is a high power device. It is able to produce a great amount of power in a small volume most particularly in a plasmoid. Link.