US4233537A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multicusp plasma containment apparatus
Assignee: Micron Technology Inc
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Filing: 1972-09-18
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Granted: 1980-11-11
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Expires: 1992-09-18
Abstract
Abstract It has been discovered that plasma containment by a chamber having multi-pole magnetic cusp reflecting walls in combination with electronic injection for electrostatic containment provides the means for generating magnetic field free quiescent plasmas for practical application in ion-pumps, electronic switches, and the like. 1250 "Alnico V" magnets 1/2"×1/2"×11/2" provide containment in one embodiment. Electromagnets embodying toroidal funneling extend the principle to fusion apparatus.
Inventors
- 👤 Rudolf Limpaecher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:14
CPC Classifications
H; H05; H05H; H05H1/00; H05H1/02; H05H1/10; H05H1/14; Y; Y02; Y02E; Y02E30/00; Y02E30/10; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/879
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
66 words
Plasma containing apparatus comprising, (a) a container vacuum tight to maintain the plasma pressure, (b) a plasma chamber within said container, (c) said chamber having magnetic multipole ion reflecting walls made up of an array of at least thirty magnetic poles of alternating sign, and (d) means for injecting electrons into said chamber in sufficient quantity to maintain the resulting plasma at a substantial negative potential.
Claim 2
Dependent Claim
66 words
Plasma containing apparatus comprising, (a) a container vacuum tight to maintain the plasma pressure, (b) a plasma chamber within said container, (c) said chamber having magnetic multipole ion reflecting walls made up of an array of at least thirty magnetic poles of alternating sign, and (d) means for injecting electrons into said chamber in sufficient quantity to maintain the resulting plasma at a substantial negative potential.
Claim 3
Dependent Claim
25 words
Plasma apparatus as defined by claim 1 (e) wherein said walls are made up of parallel ferromagnetic rectangular bars to which adhere permanent magnetic poles.
Claim 4
Dependent Claim
16 words
Plasma apparatus as defined by claim 1 (e) wherein said means comprises a heated tungsten filament.
Claim 5
Dependent Claim
18 words
Plasma apparatus as defined by claim 3 (f) wherein said walls comprise a plurality of small permanent magnets.
Claim 6
Dependent Claim
18 words
Plasma apparatus as defined by claim 1, (e) wherein said walls comprise a plurality of small permanent magnets.
Claim 7
Dependent Claim
65 words
Plasma apparatus as defined by claim 5 (f) wherein said magnets are arranged in a broken line-cusp array, each broken line-cusp being made up of a plurality of like-sense poles spaced apart by a predetermined distance, and said array comprising a plurality of parallel broken line cusps of alternately opposite sense, spaced apart by a second predetermined distance of the order of said first distance.
Claim 8
Dependent Claim
44 words
Plasma apparatus as defined by claim 5 (f) wherein said magnets are arranged in a broken line-cusp array, in further combination with: (g) an exit port in said chamber, and (h) electrostatic lens means to direct ions from said chamber into an outlet pipe.
Claim 9
Dependent Claim
32 words
Plasma apparatus as defined by claim 1 (e) wherein said chamber is in the form of a toroid, in further combination with (f) a closed core of magnetic material linking said toroid.
Claim 10
Dependent Claim
16 words
Plasma apparatus as defined by claim 1 (e) wherein said poles are provided by horse-shoe electromagnets.
Claim 11
Dependent Claim
18 words
Plasma apparatus as defined by claim 9 (f) wherein said magnets are arranged in a broken line-cusp array.
Claim 12
Dependent Claim
18 words
Plasma apparatus as defined by claim 9 (f) wherein said magnets have hollow cores proportioned for torroidal funneling.
Claim 13
Dependent Claim
39 words
Plasma apparatus as defined by claim 11 (g) wherein at least one of said magnets is linked by a closed magnetic core of magnetic material which links also wire windings by which said plasma may be heated by induction.
Claim 14
Dependent Claim
19 words
Plasma apparatus as defined by claim 9 (f) wherein said means comprises an electron gun external to said chamber.
Claim 15
Dependent Claim
26 words
Plasma apparatus as defined by claim 13 (g) wherein said electrons are carried from said gun to said chamber through the hollow core of an electromagnet.
Claim 16
Dependent Claim
19 words
Plasma apparatus as defined by claim 9 in further combination with (f) means for injecting ions into said chamber.
Claim 17
Dependent Claim
32 words
Plasma apparatus as defined by claim 15 (g) wherein said last-named means comprises (h) an ion generator, and (i) a hollow electromagnet to guide said ions from said generator into said chamber.
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) | 1983-11-11 | 1984-05-12 | 1984-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-11 | 1988-05-12 | 1988-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-11 | 1992-05-12 | 1992-11-11 | $7700.00 | Window Closed / Lapsed |