US4306175A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Induction plasma system
Assignee: THERMO JARRELL ASH Corp WALTHAM MA A CORP OF
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Filing: 1980-02-29
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Granted: 1981-12-15
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Expires: 2000-02-29
Abstract
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.
Inventors
- 👤 Robert G. Schleicher
- 👤 Stanley B. Smith, Jr.
- 👤 George A. McLean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:30
CPC Classifications
H; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/30
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
116 words
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.
Claim 2
Dependent Claim
116 words
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.
Claim 3
Dependent Claim
15 words
The system of claim 1 wherein said ignition means includes a dimensionally-shaped graphite igniter element.
Claim 4
Dependent Claim
20 words
The system of claim 2 wherein said igniter element has a tubular portion that is inserted into said plasma chamber.
Claim 5
Dependent Claim
20 words
The system of claim 2 wherein said igniter element has a conical tip that is inserted into said plasma chamber.
Claim 6
Dependent Claim
20 words
The system of claim 1 and further including an igniter insertion mechanism for inserting said igniter into said plasma chamber.
Claim 7
Dependent Claim
40 words
The system of either claim 1 or 5 and further including plasma sensor means, and means responsive to said plasma sensor means for withdrawing said igniter element from said plasma chamber upon establishment of a plasma condition in said chamber.
Claim 8
Dependent Claim
43 words
The system of claim 1 and further including a spectroanalysis system optically coupled to said plasma system, and means for introducing a spectroscopic sample to be analyzed into said plasma to raise said sample to spectroemissive levels for analysis by said spectroanalysis system.
Claim 9
Dependent Claim
13 words
The system of claim 7 wherein said sample introducing means includes a nebulizer.
Claim 10
Independent Claim
21 words
The system of any one of claims 1, 2, or 7 wherein said tank circuit includes said coil and a capacitor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-12-14 | 1985-06-15 | 1985-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-14 | 1989-06-15 | 1989-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-14 | 1993-06-15 | 1993-12-15 | $7700.00 | Window Closed / Lapsed |