Metastable argon stabilized arc devices for spectroscopic analysis

Abstract

A device is disclosed for producing an electrical arc which is stabilized by a stream of metastable argon, or some other stabilizing gas. The arc may be employed to vaporize a sample material so as to produce light for spectroscopic analysis. The vaporization is rapid so that the constituents of the sample material can be determined very quickly and accurately. The arc is highly stable so that it operates without sputtering, dancing or showing other signs of instability. Thus, the results obtained with the arc are highly accurate and repeatable. The arc is produced between a cathode in one end of an arc chamber and an anode outside the opposite end of the chamber. The arc passes out of the chamber through an orifice in a gas shaping nozzle. Argon gas is supplied to the chamber through a plurality of gas inlets, which preferably are directed at angles having peripheral components so that a whirling motion is imparted to the gas as it enters the chamber. The gas is discharged steadily out of the chamber through the nozzle and toward the anode in a restricted, shaped and controlled amount, so that the gas plays in a sloped beam over the anode. The sample material to be analyzed is preferably contained within a cavity in the anode, which is heated to a high temperature by the arc, so that the sample material will be vaporized.