US4687616A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for preventing cyclotron breakdown in partially evacuated waveguide
Assignee: United States, ENERGY THE, Department of
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Filing: 1986-01-15
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Granted: 1987-08-18
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Expires: 2006-01-15
Abstract
Abstract Cyclotron breakdown is prevented in a partially evacuated waveguide by providing a section of waveguide having an axial cut therein in order to apply a potential across the two halves of the waveguide. This section is positioned in the waveguide crossing the area of electron cyclotron resonance. The potential applied across the waveguide halves is used to deflect seed electrons into the wall of the waveguide in order to prevent ionization of gas molecules and creation of more electron ion pairs which would result in cyclotron breakdown. Support means is also disclosed for electrically isolating the waveguide halves and transition means is provided between the section of the waveguide with the axial cut and the solid waveguide at either end thereof.
Inventors
- 👤 Charles P. Moeller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:43
CPC Classifications
H; H05; H05H; H05H1/00; H05H1/02; H05H1/16; H05H1/18
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
68 words
A method of preventing cyclotron breakdown in a partially evacuated waveguide used to insert microwave energy for electron cyclotron heating in a plasma magnetic confinement device comprising the steps of, applying a static magnetic field for confining the plasma in said device and applying an electrostatic field in order to remove electrons to prevent ionization of gas molecules and creation of more electron ion pairs in said waveguide.
Claim 2
Independent Claim
68 words
A method of preventing cyclotron breakdown in a partially evacuated waveguide used to insert microwave energy for electron cyclotron heating in a plasma magnetic confinement device comprising the steps of, applying a static magnetic field for confining the plasma in said device and applying an electrostatic field in order to remove electrons to prevent ionization of gas molecules and creation of more electron ion pairs in said waveguide.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein said electrostatic field has a substantial component along said static magnetic field.
Claim 4
Dependent Claim
29 words
The method of claim 2 wherein said electrostatic field is applied along said static magnetic field in order to run said seed electrons into the wall of said waveguide.
Claim 5
Dependent Claim
34 words
The method of claim 3 wherein said seed electrons are run into said wall in a time short compared to the time for ionization of the gas molecules in said waveguide by accelerated electrons.
Claim 6
Dependent Claim
136 words
In a magnetic plasma confining device including a torroidally shaped vacuum vessel having field coils wound around said vessel in order to generate a static magnetic field for plasma confinement, a waveguide running from the low magnetic field side of said vacuum vessel across a portion wherein cyclotron resonance occurs to the high field side of said vacuum vessel, a launch means positioned at the end of said waveguide to reflect microwave energy back across said vessel into said plasma, and means for applying microwave energy through said waveguide against said launch means, the improvement comprising means for applying a static electric field across a portion of said waveguide in the area crossing said cyclotron resonance whereby seed electrons are removed in order to prevent ionization of gas molecules and creation of more electron ion pairs.
Claim 7
Dependent Claim
136 words
In a magnetic plasma confining device including a torroidally shaped vacuum vessel having field coils wound around said vessel in order to generate a static magnetic field for plasma confinement, a waveguide running from the low magnetic field side of said vacuum vessel across a portion wherein cyclotron resonance occurs to the high field side of said vacuum vessel, a launch means positioned at the end of said waveguide to reflect microwave energy back across said vessel into said plasma, and means for applying microwave energy through said waveguide against said launch means, the improvement comprising means for applying a static electric field across a portion of said waveguide in the area crossing said cyclotron resonance whereby seed electrons are removed in order to prevent ionization of gas molecules and creation of more electron ion pairs.
Claim 8
Dependent Claim
19 words
The device of claim 5 wherein said static electric field has a substantial component along said static magnetic field.
Claim 9
Dependent Claim
33 words
The device of claim 6 wherein said means for applying a static electric field includes an axial cut in said portion of said waveguide in the plane of the microwave rf electric field.
Claim 10
Dependent Claim
34 words
The device of claim 7 wherein said means for applying a static electric field includes insulating support means for joining the two sides of said portion of said waveguide defined by said axial cut.
Claim 11
Dependent Claim
25 words
The device of claim 8 wherein transition means is provided between the ends of said portion of said waveguide and the remainder of said waveguide.
Claim 12
Dependent Claim
34 words
The device of claim 9 wherein said transition means includes an insulating gap defined by a metal shim and has alternating quarter wavelength radial waveguides cut in the faces of the solid waveguide sections.
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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) | 1990-08-17 | 1991-02-16 | 1991-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-17 | 1995-02-16 | 1995-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-17 | 1999-02-16 | 1999-08-18 | $7700.00 | Window Closed / Lapsed |