Application of a Streak Camera for Optical Diagnostics of Nanosecond Repetitively Pulsed Plasma Discharges

摘要

A new experimental diagnostic is developed to study the dynamics of nanosecond plasma discharges with extremely high temporal resolution. A streak camera is used in the experiment with and without a spectrometer to capture time resolved plasma spectra and images. A high bandwidth oscilloscope with data logging capability is used with the camera and plasma pulser to measure current, voltage, plasma lifetime and energy simultaneously for each acquisition of the streak camera. Two conical electrodes with a separation of 1 to 3 mm and a pulse repetition frequency of 5 kHz are used to generate the plasma discharge at 300 K and 1 atm. Time-resolved direct imaging shows extremely fast development of the plasma with 3 distinct phases, and the streak-spectroscopy results indicate bi-exponential decay of the second positive system of molecular nitrogen with rapid decay during the first phase and a relatively slower decay during the second phase.