US 4,060,708 A · 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.

Claims23

Dependent claims

A stabilized arc device to produce light for spectroscopic analysis,

said device comprising a housing having a chamber therein,
a cathode within said chamber,
an anode electrode outside said housing,
direct current electrical power supply means having positive and negative terminals connected to said respective anode and cathode electrodes,
gas supply means for introducing a pressurized stabilizing gas into said chamber,
a nozzle electrode having a gas discharge orifice therein and disposed on said housing for discharging a stream of the stabilizing gas from said chamber to said anode electrode to stabilize an electrical arc between said cathode and anode electrodes,
said nozzle electrode being made of an electrically conductive material,
and electrically insulating means for insulating said nozzle electrode from said housing and also from said cathode and anode electrodes whereby said nozzle electrode can assume an intermediate electrical potential between the electrical potentials of said cathode and anode electrodes,
said anode electrode having receptacle means for holding a sample material to be vaporized by the arc to produce light for spectroscopic analysis.

6 more elements

A stabilized arc device to produce light for spectroscopic analysis,

said device comprising a housing with a chamber therein having a generally circular cross-section,
a cathode electrode disposed generally axially within said chamber,
an anode electrode disposed substantially axially outside said housing,
gas supply means for introducing a pressurized stabilizing gas into said chamber,
orifice means on said housing and forming a generally axial orifice connecting with said chamber for discharging a stream of the stabilizing gas from said chamber to said anode electrode to stabilize an electrical arc between said cathode and anode electrodes for producing light for spectroscopic analysis,
said anode electrode having receptacle means for holding a sample material to be vaporized by said arc for spectroscopic analysis,
said cathode electrode having a generally axial opening therein,
and means for producing an outward flow of some of the stabilizing gas from said chamber and through said opening in said cathode electrode to cause the arc to maintain a cathode spot within said opening in said cathode electrode.

5 more elements

Dependencies are inferred from the claim text.

Metastable argon stabilized arc devices for spectroscopic analysis

Life of this patent

Metastable argon stabilized arc devices for spectroscopic analysis

Life of this patent

Abstract

Claims23