US 4,306,175 A · Induction plasma system

Abstract

An induction plasma system includes a plasma chamber, a high frequency electrical coil that surrounds the chamber, and an oscillator for energizing the coil to establish a plasma maintaining condition in the chamber. The oscillator tank circuit includes the coil, and is tuned so that it is essentially at resonance when a plasma condition is established in the chamber. Ignition means is arranged for initiating a plasma condition, and is constructed such that insertion of the ignition means into the chamber in the absence of a plasma condition shifts the impedance condition in the chamber to essentially the same tuned condition that exists when a plasma condition is established in the plasma chamber, but without need to adjust any component of the tank circuit.

Claims9

Dependent claims

An induction plasma system comprising

means defining a plasma chamber,
a high frequency electrical coil surrounding said chamber,
an oscillator for energizing said coil to establish a plasma maintaining condition in said chamber,
said oscillator including a tank circuit tuned essentially to resonance with a plasma condition in said chamber,
means for flowing gas through said chamber, and
ignition means for disposition in said chamber to initiate a plasma condition,
said ignition means being constructed such that insertion of said ignition means into said chamber in the absence of a plasma condition shifts the impedance condition in said chamber to essentially the resonance condition that is established with said plasma condition without retuning said tank circuit.

4 more elements

Dependencies are inferred from the claim text.

Induction plasma system

Life of this patent

Induction plasma system

Life of this patent

Abstract

Claims9