US4017404A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for low temperature ashing using radio frequency excited gas plasma
Assignee: United States Department of Health and Human Services
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Filing: 1976-03-11
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Granted: 1977-04-12
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Expires: 1996-03-11
Abstract
Abstract An apparatus for low temperature ashing of specimens is provided. The specimens to be ashed are first freeze dried and then reduced to an ash by a radio frequency (RF) excited gas plasma in a device which includes a reaction chamber, means to reduce the pressure in the chamber, means communicating with the chamber for supplying a stream of reaction gas thereto, and an RF means including a driven and receiver antenna pair with an annular antenna around the chamber and a planer antenna associated with the end wall of the chamber.
Inventors
- 👤 Larry E. Habeger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:00
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/12; G01N1/00; G01N1/28; G01N1/44; Y; Y10; Y10S; Y10S422/00; Y10S422/906
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
103 words
A low temperature ashing device comprising: side and end walls defining a gas tight reaction chamber for containing a specimen to be ashed; means communicating with said chamber for reducing the pressure therein; means communicating with said chamber for supplying a stream of reaction gas thereto; and Rf means for coupling a radio frequency output to said gas and generating a plasma to produce low temperature ashing of a specimen therein, said RF means including a driven and receiving antenna pair having an annular antenna encompassing the side walls with a spaced substantially planer antenna associated with an end wall of said chamber.
Claim 2
Dependent Claim
103 words
A low temperature ashing device comprising: side and end walls defining a gas tight reaction chamber for containing a specimen to be ashed; means communicating with said chamber for reducing the pressure therein; means communicating with said chamber for supplying a stream of reaction gas thereto; and Rf means for coupling a radio frequency output to said gas and generating a plasma to produce low temperature ashing of a specimen therein, said RF means including a driven and receiving antenna pair having an annular antenna encompassing the side walls with a spaced substantially planer antenna associated with an end wall of said chamber.
Claim 3
Dependent Claim
30 words
The low temperature ashing device in accordance with claim 1 wherein said chamber is substantially cylindrical and of a height substantially on the order of 2 times the diameter thereof.
Claim 4
Dependent Claim
31 words
The low temperature ashing device in accordance with claim 2 wherein said chamber comprises two substantially equal cylindrical chamber halves removably joined together by means of a tapered ground joint therebetween.
Claim 5
Dependent Claim
44 words
The low temperature ashing device in accordance with claim 1 further comprising an annular water jacket disposed around said chamber for cooling thereof, means to circulate water through said chamber and wherein said annular antenna is disposed around the exterior of said water jacket.
Claim 6
Dependent Claim
38 words
The low temperature ashing device in accordance with claim 1 further comprising specimen stirring means including a stirring bar disposed within said chamber and a magnetic drive exterior of said chamber to induce rotation of said stirring bar.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-11 | 1980-10-11 | 1981-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-11 | 1984-10-11 | 1985-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-11 | 1988-10-11 | 1989-04-12 | $7700.00 | Window Closed / Lapsed |