High-Pressure Helium Plasma Produced in the Local Electric Fields of a Piezoelectric Transformer

A millimeter-scale confined helium plasma was produced at 177 kPa by placing a piezoelectric transformer (PT) in the vicinity of the quartz tube and stimulating the transformer into an electromechanical resonance. The resulting plasma occurred at twice the electromechanical resonance frequency of the transformer. Time-resolved high-speed measurements of luminous emissions and simultaneous measurem...