US4147995A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Foil moderated radioactive preionization system for gas lasers
Assignee: United States Department of the Air Force
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Filing: 1977-08-19
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Granted: 1979-04-03
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Expires: 1997-08-19
Abstract
Abstract A safe, radioactive preionization system having a thin metallic film or foil, either placed in front of or deposited on the surface of radioactive sources, in order to isolate the radioactive source from laser discharge regions and to produce copious secondary emission electrons. The film or foil prevents bombardment of the radioactive source by discharge electrons and/or ions. In addition, the secondary emission electrons ejected from the metallic film or foil are more numerous than the radioactive decay particles which produce them and have lower energies. Hence, they are much more efficient preionization agents than the high energy particles emitted by the radioactive source.
Inventors
- 👤 Clare C. Leiby, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:29
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/09; H01S3/097; H01S3/0971; H01S3/09713; H01S3/09716
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
56 words
In a gas laser having a resonant cavity and a pair of electrodes located within said cavity, the improvement therein comprises a radioactive source situated within said cavity and a thin metallic foil interposed between said radioactive source and at least one of said electrodes thereby forming a safe, radioactive preionization system for said gas laser.
Claim 2
Dependent Claim
56 words
In a gas laser having a resonant cavity and a pair of electrodes located within said cavity, the improvement therein comprises a radioactive source situated within said cavity and a thin metallic foil interposed between said radioactive source and at least one of said electrodes thereby forming a safe, radioactive preionization system for said gas laser.
Claim 3
Dependent Claim
44 words
In a gas laser having a resonant cavity and a pair of electrodes located within said cavity as defined in claim 1 wherein said thin metallic foil is mounted within a frame, said frame being secured within said resonant cavity adjacent said radioactive source.
Claim 4
Dependent Claim
35 words
In a gas laser having a resonant cavity and a pair of electrodes located within said cavity as defined in claim 2 wherein said thin metallic foil is located extremely close to said radioactive source.
Claim 5
Dependent Claim
34 words
In a gas laser having a resonant cavity and a pair of electrodes located within said cavity as defined in claim 1 wherein said thin metallic foil is deposited directly upon said radioactive source.
Claim 6
Dependent Claim
37 words
In a gas laser having a resonant cavity and a pair of electrodes located within said cavity as defined in claim 4 wherein said thin metallic foil is made of a material having a low atomic weight.
Claim 7
Dependent Claim
37 words
In a gas laser having a resonant cavity and a pair of electrodes located within said cavity as defined in claim 3 wherein said thin metallic foil is made of a material having a low atomic weight.
Claim 8
Dependent Claim
66 words
In a gas laser having a resonant cavity and a pair of electrodes located within said cavity as defined in claim 1 further comprising another radioactive source situated within said resonant cavity, another thin metallic foil interposed between said other source and said electrodes and wherein the shortest distance between each of said foils and said electrodes is greater than half the distance between said electrodes.
Claim 9
Independent Claim
77 words
A method of providing a safe, radioactive preionization system for use in a gas laser having a resonant cavity and a pair of electrodes, said method comprising the steps of: (a) mounting a radioactive source within said resonant cavity of said gas laser, and (b) interposing a thin metallic foil between said radioactive source and at least one of said electrodes thereby isolating said radioactive source from the laser discharge region and producing copious secondary electron emissions.
Claim 10
Independent Claim
77 words
A method of providing a safe, radioactive preionization system for use in a gas laser having a resonant cavity and a pair of electrodes, said method comprising the steps of: (a) mounting a radioactive source within said resonant cavity of said gas laser, and (b) interposing a thin metallic foil between said radioactive source and at least one of said electrodes thereby isolating said radioactive source from the laser discharge region and producing copious secondary electron emissions.
Claim 11
Dependent Claim
44 words
A method of providing a safe, radioactive preionization system for use in a gas laser having a resonant cavity and a pair of electrodes as defined in claim 8 further comprising the step of depositing said thin metallic foil directly on said radioactive source.
Claim 12
Dependent Claim
44 words
A method of providing a safe, radioactive preionization system for use in a gas laser having a resonant cavity and a pair of electrodes as defined in claim 9 wherein said thin metallic foil is made of a material having a low atomic weight.
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) | 1982-04-02 | 1982-10-02 | 1983-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-02 | 1986-10-02 | 1987-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-02 | 1990-10-02 | 1991-04-03 | $7700.00 | Window Closed / Lapsed |