An Electronic,Adjustable-Waveform Current Generator for Use with a Quarter-Wave Resonant Spark Source

Abstract

A newly designed current generator for use with a quarter-wave spark source for a fundamental spectroscopic study of spark discharge chemistry is described. The generator outputs a trapezoidal discharge current waveform whose duration and amplitude are adjustable independently of the source repetition rate up to 5 μsec and 30 A, respectively. A multi-π section LC ladder network and a fast SCR are combined for the new generator to produce the adjustable discharge current waveform, in place of a single RC filter for a conventional current generator. The LC network functions as a current width stretcher and the SCR shapes the pulse into the desired duration by shunt clipping the tail. To evaluate the performance of the new current generator, transient emission waveforms of Cu lines are compared for a trapezoidal current waveform and a simple relaxation discharge waveform with that generated from the conventional generator.

Keywords

Spark source Emission spectroscopy Pulse generator

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