Characterization of Vibrational and Rotational N2 Spectral Bands in an Electron Beam Produced Plasma Via a 1.3m High-Resolution Multi-View Spectrometer

A high-resolution spectroscopic characterization is conducted on the vibrational and rotational spectral emissions of an N2 plasma produced by an electron beam. The electron beam is initiated by the Naval Research Laboratory’s Febetron pulsed-power generator capable of 80 kV and 4 kA peak voltage and current pulses with a 100 ns pulse time width. The beam is directed into an N2 pressurized chamber, ranging in pressures from 10mTorr to 10 Torr, where the electron beam excites the N2 gas into both molecular and atomic emissions. A spectroscopic analysis is conducted on these emissions from the near-UV to visible (300-650 nm) by means of a sub-angstrom resolution 1.3 m focal length Czerny-Turner spectrometer. Multiple simultaneous spectral measurements are taken per pulse enabling measurements of spatial variations of the plasma spectra through a 7-fiber input array. Imaging of the spectra is conducted by a 2D intensified gated CCD over small time increments to analyze the time-resolved evolution of the emissions.