The emission of light from electric discharges of microsecond durations in gases at atmospheric pressure

This paper compares the performance of four types of spark discharge, widely used (1-4) as light sources of high intensity and short duration. Using the same capacitor and stored energy, electrical and light emission waveforms, and integrated spectra, were recorded for each type of discharge. Air sparks, both free and guided across the surface of an insulator, and argon sparks both within a jet of argon, and enclosed by a quartz capillary tube, were studied in this manner. The results are discussed in terms of the possible applications in fast photography and the photo-irradiation of materials Particular attention is drawn to the novel properties of the discharge within an argon jet, as this affords a source of high positional stability and repeatability of performance, while retaining the high intensity and small size of other discharges.