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US4173728A Expired / Lapsed US ⏱️ 0.0 years remaining

Pulsed cesium discharge light source

Assignee: General Electric Co
•
Filing: 1978-05-19
•
Granted: 1979-11-06
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Expires: 1998-05-19
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Abstract

Abstract A metal vapor discharge lamp includes a cathode comprising a reservoir of liquid cesium. Metallic cesium which is eroded from the cathode surface by the action of the discharge is returned to the reservoir by the combined effects of gravity, evaporation, condensation, and diffusion to provide a highly stable, long-lived lamp. The intense infrared pulse output of cesium vapor discharge lamps of the present invention is well suited for triggering light-activated semiconductor switches through dielectric pipe networks and for pumping neodymium glass or neodymium-YAG lasers.

Inventors

  • 👤 Harald L. Witting

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 09:20
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/09; H01S3/091; H01S3/0915; H01S3/092; H01J; H01J13/00; H01J13/02; H01J13/04; H01J13/06; H01J13/08; H01J61/00; H01J61/02; H01J61/12; H01J61/18; H01J61/22

Claims Analysis

Total Claims: 27
Claim 1
Independent Claim 107 words
A long-lived metal vapor discharge lamp, suitable for operation in a pulsed mode, comprising: an evacuable arc tube having a first end and a second end; a solid metal anode disposed in the first end of said arc tube; a liquid cesium reservoir disposed in the second end of said arc tube; a cathode comprising a conductive material capable of adsorbing cesium, said cathode pointedly protruding from said reservoir so as to provide a preferred discharge path; and a fill gas, including cesium vapor, disposed within said arc tube between said anode and said cathode at a vapor pressure between approximately 5 torr and approximately 100 torr.
Claim 2
Dependent Claim 107 words
A long-lived metal vapor discharge lamp, suitable for operation in a pulsed mode, comprising: an evacuable arc tube having a first end and a second end; a solid metal anode disposed in the first end of said arc tube; a liquid cesium reservoir disposed in the second end of said arc tube; a cathode comprising a conductive material capable of adsorbing cesium, said cathode pointedly protruding from said reservoir so as to provide a preferred discharge path; and a fill gas, including cesium vapor, disposed within said arc tube between said anode and said cathode at a vapor pressure between approximately 5 torr and approximately 100 torr.
Claim 3
Dependent Claim 18 words
The lamp of claim 1 further including an evacuable envelope surrounding said arc tube and spaced apart therefrom.
Claim 4
Dependent Claim 17 words
The lamp of claim 2 wherein the space between said envelope and said arc tube is evacuated.
Claim 5
Dependent Claim 18 words
The lamp of claim 2 further comprising an inert gas disposed between said arc tube and said envelope.
Claim 6
Dependent Claim 10 words
The lamp of claim 2 wherein said envelope is glass.
Claim 7
Dependent Claim 28 words
The lamp of claim 1 wherein said arc tube, said cathode, and said anode comprise materials which are resistant to chemical attack by cesium vapor and liquid cesium.
Claim 8
Dependent Claim 22 words
The lamp of claim 6 wherein said arc tube comprises materials selected from the group consisting of transparent alumina and translucent alumina.
Claim 9
Dependent Claim 24 words
The lamp of claim 6 wherein said cathode and said anode comprise material selected from the group consisting of tunsten, platinum, iridium, and osmium.
Claim 10
Dependent Claim 12 words
The lamp of claim 1 wherein said fill gas further comprises xenon.
Claim 11
Dependent Claim 18 words
The lamp of claim 9 wherein the pressure of said xenon is approximately 10 torr at room temperature.
Claim 12
Dependent Claim 23 words
The lamp of claim 1 further including metal end caps disposed at the first end and the second end of said arc tube.
Claim 13
Dependent Claim 11 words
The lamp of claim 11 wherein said end caps comprise niobium.
Claim 14
Dependent Claim 21 words
The lamp of claim 1 wherein said cathode comprises material selected from the group consisting of tungsten, platinum, iridium, and osmium.
Claim 15
Dependent Claim 28 words
The lamp of claim 1 in which the diameter of said arc tube is such that said reservoir is maintained in said second end thereof by capillary action.
Claim 16
Dependent Claim 22 words
The lamp of claim 1 further including a supply of pulsed electric current connected in series with said cathode and said anode.
Claim 17
Dependent Claim 20 words
The lamp of claim 15 further including means to produce a direct electrical current between said cathode and said anode.
Claim 18
Dependent Claim 17 words
The lamp of claim 16 wherein said direct electrical current is between 0.5 ampere and 1.5 amperes.
Claim 19
Dependent Claim 41 words
The lamp of claim 15 further including means for maintaining the pressure of said cesium vapor at a value between approximately 1 torr and approximately 300 torr at such time as electrical current is flowing between said cathode and said anode.
Claim 20
Dependent Claim 32 words
The lamp of claim 18 wherein said means for maintaining the pressure of said cesium vapor includes means for imposing and adjusting a direct electrical current between said anode and said cathode.
Claim 21
Dependent Claim 24 words
The lamp of claim 18 wherein said means for maintaining the pressure of said cesium vapor includes heating means disposed adjacent said arc tube.
Claim 22
Dependent Claim 25 words
The lamp of claim 18 wherein said means for maintaining the pressure of said cesium vapor includes heat shields disposed outside of said arc tube.
Claim 23
Dependent Claim 33 words
The lamp of claim 1 further including means for maintaining the temperature of walls of said arc tube, in regions above said cathode, at a temperature above the temperature of said cesium pool.
Claim 24
Dependent Claim 16 words
The lamp of claim 1 wherein the pressure of said cesium vapor is approximately 40 torr.
Claim 25
Dependent Claim 29 words
The lamp of claim 1 further including a plurality of dielectric light pipes disposed to receive and conduct radiation emanating from a region between said cathode and said anode.
Claim 26
Dependent Claim 92 words
A long-lived metal vapor discharge lamp, suitable for operation in a pulsed mode, comprising: an evacuable arc tube having a first end and a second end; a solid metal anode disposed in the first end of said arc tube; a reentrant metal end cap sealably closing the second end of said tube; a liquid cesium reservoir disposed in said reentrant end cap; and a fill gas, including cesium vapor, disposed within said arc tube between said anode and said cathode at a vapor pressure between approximately 5 torr and approximately 100 torr.
Claim 27
Dependent Claim 92 words
A long-lived metal vapor discharge lamp, suitable for operation in a pulsed mode, comprising: an evacuable arc tube having a first end and a second end; a solid metal anode disposed in the first end of said arc tube; a reentrant metal end cap sealably closing the second end of said tube; a liquid cesium reservoir disposed in said reentrant end cap; and a fill gas, including cesium vapor, disposed within said arc tube between said anode and said cathode at a vapor pressure between approximately 5 torr and approximately 100 torr.

References Cited (Backward Citations)

US2116689A Cited
US3317776A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-11-05 1983-05-07 1983-11-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-11-05 1987-05-07 1987-11-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-11-05 1991-05-07 1991-11-06 $7700.00 Window Closed / Lapsed

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