Patent US3612941A successfully refreshed from Google Patents.
US3612941A
Expired / Lapsed
US
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Pulsed field emission cold cathode with means for replacing stripped adsorbed gas layer
Assignee: Fleet National Bank
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Filing: 1970-04-24
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Granted: 1971-10-12
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Expires: 1990-04-24
Abstract
Abstract The present disclosure involves methods and apparatus for continually replacing the adsorbed gas layer stripped from highcurrent field-emission cold cathodes by the effects of highvoltage pulsing the cathode.
Inventors
- 👤 Samuel V Nablo
- 👤 A Stuart Denholm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 06:27
CPC Classifications
H; H01; H01J; H01J19/00; H01J19/82
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
110 words
An electron-producing apparatus having, in combination, an anode and a cold, high-current field emission cathode; means for applying voltage pulses between the anode and cathode sufficient to draw impulses of high emission current directly from the cold cathode, the external cathode surface facing the anode being subject to the removal of inherent electron-ion plasma layer thereupon by the application of said pulses, exposing the cathode material itself to destruction upon the continued application of said pulses; and means for effectively providing a continual plasma replacement layer upon said external cathode surface comprising means for continually supplying to said surface a low atomic number low-ionization-potential gas readily adsorbable upon said surface.
Claim 2
Dependent Claim
110 words
An electron-producing apparatus having, in combination, an anode and a cold, high-current field emission cathode; means for applying voltage pulses between the anode and cathode sufficient to draw impulses of high emission current directly from the cold cathode, the external cathode surface facing the anode being subject to the removal of inherent electron-ion plasma layer thereupon by the application of said pulses, exposing the cathode material itself to destruction upon the continued application of said pulses; and means for effectively providing a continual plasma replacement layer upon said external cathode surface comprising means for continually supplying to said surface a low atomic number low-ionization-potential gas readily adsorbable upon said surface.
Claim 3
Dependent Claim
39 words
Apparatus as claimed in claim 1 and in which the said supplying means comprises a porous cathode portion and means for applying said gas into the cathode structure and through the pores of said portion to said external surface.
Claim 4
Dependent Claim
21 words
Apparatus as claimed in claim 2 and in which said cathode has an internal gas-receiving passage communicating with said porous portion.
Claim 5
Dependent Claim
24 words
Apparatus as claimed in claim 1 and in which said cathode comprises a clathrate portion containing the said gas in bonded but releasable form.
Claim 6
Dependent Claim
43 words
Apparatus as claimed in claim 1 and in which said flowing means comprises means for moving successive portions of the cathode through a relatively high-pressure gas-containing region to adsorb gas thereupon and thence into a relatively low-pressure operative pulsing position opposite said anode.
Claim 7
Dependent Claim
27 words
Apparatus as claimed in claim 1 and in which the said gas is selected from the group consisting of hydrogen, helium, nitrogen and alkali earth metal vapors.
Claim 8
Independent Claim
51 words
A method of preventing the destruction of a cold, high current field emission cathode by pulses that remove the inherent electron-ion plasma layer thereupon, that comprises, pulsing said cathode, and, during said pulsing, continually supplying to the cathode surface a low atomic number, low-ionization-potential gas readily adsorbable upon the cathode surface.
Claim 9
Independent Claim
51 words
A method of preventing the destruction of a cold, high current field emission cathode by pulses that remove the inherent electron-ion plasma layer thereupon, that comprises, pulsing said cathode, and, during said pulsing, continually supplying to the cathode surface a low atomic number, low-ionization-potential gas readily adsorbable upon the cathode surface.
Claim 10
Dependent Claim
25 words
A method as claimed in claim 7 and in which said supplying is effected by releasinG said gas internally from a portion of said cathode.
References Cited (Backward Citations)
US2716713A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-11 | 1975-04-12 | 1975-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-11 | 1979-04-12 | 1979-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-11 | 1983-04-12 | 1983-10-12 | $7700.00 | Window Closed / Lapsed |