Emission topography of a stable spark discharge train

Time and space resolved spectroscopy are used to photograph the emission from a stable spark discharge train attacking a rotating copper beveled disk in flowing argon. The spark is generated at 60 Hz with a Bardocz type adjustable waveform source. Photographic density over background of sets of lines in the Cu I and Cu II term system is plotted as a function of lateral displacement from the vertical interelectrode axis and time at discrete horizontal distances away from the copper cathode surface to form spatially connected sets of lateral emission profiles. Data from secondary cathodes of silver and gold are presented, along with spectral evidence for radial compression of the cathode jets accompanying their charge transfer ionization and excitation. Spectrochemical applications utilizing time-space structural details are discussed.