US3831052A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hollow cathode gas discharge device
Assignee: Raytheon Co
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Filing: 1973-05-25
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Granted: 1974-08-20
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Expires: 1993-05-25
Abstract
Abstract The hollow cathode gas discharge device is configured with a maximized cathode-to-anode area ratio to operate in a lowpressure glow discharge mode to generate a plasme of adequate density from which electrons or ions can be extracted and accelerated. This permits the gas pressure to be kept low to avoid Paschen breakdown in the high voltage acceleration region. The invention herein described was made in the course of or under a Contract or subcontract thereunder with the Department of the Navy.
Inventors
- 👤 R Knechtli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:06
CPC Classifications
H; H01; H01J; H01J3/00; H01J3/02; H01J3/025; H01J17/00; H01J17/02; H01J17/04; H01J17/06; H01J17/066; H01J17/38; H01J17/40; H01J17/44; H01S; H01S3/00; H01S3/09; H01S3/097; H01S3/09707; H01J2893/00; H01J2893/0064; H01J2893/0065; H01J2893/0066; H01J2893/0068
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
192 words
A hollow cathode plasma discharge device comprising: walls defining a hollow cathode space, said walls comprising an anode wall and a cathode wall, said anode wall and said cathode wall together defining the exterior boundaries of a lowpressure glow discharge plasma, said anode wall being positioned so that it does not substantially intrude into the plasma, the ratio of anode area to cathode area being smaller than unity for low-pressure glow discharge plasma mode operation; means for initiating plasma discharge interiorly of said space so that plasma discharge can be ignited by said initiation means and then transferred to said anode wall; one of said walls being perforated so that particles can be extracted through said perforation into space exterior of said perforated wall; an accelerator electrode positioned exteriorly of said hollow cathode space to accelerate particles passing out through said wall perforation; and a vessel enclosing at least said perforation and said accelerator electrode to maintain pressure within said vessel and within said cathode at subatmospheric pressure to cause conditions between said perforation and said accelerator electrode to be outside the breakdown region of the Paschen curve for the particular gas.
Claim 2
Dependent Claim
192 words
A hollow cathode plasma discharge device comprising: walls defining a hollow cathode space, said walls comprising an anode wall and a cathode wall, said anode wall and said cathode wall together defining the exterior boundaries of a lowpressure glow discharge plasma, said anode wall being positioned so that it does not substantially intrude into the plasma, the ratio of anode area to cathode area being smaller than unity for low-pressure glow discharge plasma mode operation; means for initiating plasma discharge interiorly of said space so that plasma discharge can be ignited by said initiation means and then transferred to said anode wall; one of said walls being perforated so that particles can be extracted through said perforation into space exterior of said perforated wall; an accelerator electrode positioned exteriorly of said hollow cathode space to accelerate particles passing out through said wall perforation; and a vessel enclosing at least said perforation and said accelerator electrode to maintain pressure within said vessel and within said cathode at subatmospheric pressure to cause conditions between said perforation and said accelerator electrode to be outside the breakdown region of the Paschen curve for the particular gas.
Claim 3
Dependent Claim
191 words
A hollow cathode plasma discharge device comprising: walls defining a hollow cathode space, said walls comprising an anode wall and a cathode wall, said anode wall and said cathode wall together defining the exterior boundaries of a low-pressure glow discharge plasma, said anode wall being positioned so that it does not substantially intrude into the plasma, the ratio of anode area to cathode area being smaller than unity for low-pressure glow discharge plasma mode operation; an auxiliary anode positioned interiorly of said space for initial ignition of the plasma disCharge so that plasma discharge can be sustained by said anode wall; one of said walls being perforated so that particles can be extracted through said perforation into space exterior of said perforated wall; an accelerator electrode positioned exteriorly of said hollow cathode space to accelerate particles passing out through said wall perforation; and a vessel enclosing at least said perforation and said accelerator electrode to maintain pressure within said vessel and within said cathode at subatmospheric pressure to cause conditions between said perforation and said accelerator electrode to be outside the breakdown region of the Paschen curve for the particular gas.
Claim 4
Dependent Claim
191 words
A hollow cathode plasma discharge device comprising: walls defining a hollow cathode space, said walls comprising an anode wall and a cathode wall, said anode wall and said cathode wall together defining the exterior boundaries of a low-pressure glow discharge plasma, said anode wall being positioned so that it does not substantially intrude into the plasma, the ratio of anode area to cathode area being smaller than unity for low-pressure glow discharge plasma mode operation; an auxiliary anode positioned interiorly of said space for initial ignition of the plasma disCharge so that plasma discharge can be sustained by said anode wall; one of said walls being perforated so that particles can be extracted through said perforation into space exterior of said perforated wall; an accelerator electrode positioned exteriorly of said hollow cathode space to accelerate particles passing out through said wall perforation; and a vessel enclosing at least said perforation and said accelerator electrode to maintain pressure within said vessel and within said cathode at subatmospheric pressure to cause conditions between said perforation and said accelerator electrode to be outside the breakdown region of the Paschen curve for the particular gas.
Claim 5
Dependent Claim
53 words
The device of claim 2 wherein an additional perforated electrode or conducting mesh is placed between said perforated anode and said accelerator electrode to serve as a control grid controlling the current of extracted electrons, the potential of said control grid being between the cathode potential and the potential of the accelerator electrode.
Claim 6
Dependent Claim
24 words
The device of claim 3 wherein said perforated wall is a perforated anode wall so that electrons are the particles extracted from the plasma.
Claim 7
Dependent Claim
42 words
The device of claim 3 wherein said vessel includes an electron transmissive window, and said electron transmissive window is said accelerator electrode so that electrons accelerated to said window are transmitted through said window into an atmosphere of arbitrary pressure and composition.
Claim 8
Dependent Claim
42 words
The device of claim 4 wherein said vessel includes an electron transmissive window, and said electron transmissive window is said accelerator electrode so that electrons accelerated to said window are transmitted through said window into an atmosphere of arbitrary pressure and composition.
Claim 9
Dependent Claim
80 words
The device of claim 3 wherein said perforated wall is a perforated cathode wall so that ions can be extracted from the plasma, said accelerator electrode being spaced from said perforated cathode wall and being connected to a negative electric voltage with respect to said cathode to accelerate ions from said perforated cathode wall, said vessel maintaining the space between said perforated cathode wall and said accelerator electrode in the non-breakdown region of the Paschen curve for the particular gas.
Claim 10
Dependent Claim
67 words
The device of claim 7 wherein a control grid consisting of a perforated electrode or conducting mesh is placed between said perforated cathode wall and said negative accelerator electrode to control the current of the extracted ion, the potential of said control grid being negative with respect to the cathode and the ion optical design of said control grid being such as to keep ion interception low.
Claim 11
Dependent Claim
49 words
The device of claim 7 wherein a control grid consisting of a perforated electrode or conducting mesh is placed between said perforated cathode wall and said negative accelerator electrode, the potential of said control grid being substantially equal to cathode potential or being positive with respect to cathode potential.
References Cited (Backward Citations)
US3262003A
Cited
US3411035A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |