Patent US3792282A successfully refreshed from Google Patents.
US3792282A
Expired / Lapsed
US
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Stimulated exoelectron emission dosimeter having high spatial resolution
Assignee: Bendix Corp
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Filing: 1971-09-27
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Granted: 1974-02-12
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Expires: 1991-09-27
Abstract
Abstract A dosimeter having high spatial resolution is described. The inventive dosimeter includes a sample of a material which exhibits exoelectron emission during optical, thermal or radiation stimulation after having been exposed to the type of radiation the detection of which is desired. Exoelectrons emanating from the sample are detected by a microchannel plate (MCP) which releases a large number of electrons for each electron it receives. The electrons emanating from the output surface of the microchannel plate impact a detection surface which yields a visual indication in response to the impacting electrons. Because microchannel plates multiply electrons in well defined channels the spatial distribution of electrons leaving the surface of the sample is preserved at the output surface of the MCP. The spatial distribution of electrons impacting the detection surface is thus identical to that of the electrons emanating from the surface of the sample material. Accordingly, the spatial distribution of the radiation to which the sample was originally exposed is duplicated across the detection surface, thereby making it possible to determine both the intensity and spatial distribution of the radiation to which the sample was subjected.
Inventors
- 👤 P Braunlich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:06
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
167 words
A dosimeter having high spatial resolution comprising: a sample of exoelectron emissive material having a smooth, homogenous surface for receiving radiation, the spatial distribution and intensity of which is to be determined, said exoelectron emissive material characterized by the property, wherein electrons are stored in an excited state along the surface of said material upon receiving said radiation and said stored electrons are emitted as exoelectrons when said material is stimulated by energy substantially less than the energy required to cause thermionic emission or photoemission; a electron multiplier in the proximity of said sample, for receiving exoelectrons emanating from said sample and multiplying said exoelectrons on a point-to-point basis so that pattern information contained in said exolectrons is preserved in said multiplier; detector means in the proximity of said multiplier for receiving said multiplied electrons and yielding an output indicative of the spatial distribution of said radiation; and means for stimulating the emission of exoelectrons from said sample after the exposure of said sample to said radiation.
Claim 2
Dependent Claim
167 words
A dosimeter having high spatial resolution comprising: a sample of exoelectron emissive material having a smooth, homogenous surface for receiving radiation, the spatial distribution and intensity of which is to be determined, said exoelectron emissive material characterized by the property, wherein electrons are stored in an excited state along the surface of said material upon receiving said radiation and said stored electrons are emitted as exoelectrons when said material is stimulated by energy substantially less than the energy required to cause thermionic emission or photoemission; a electron multiplier in the proximity of said sample, for receiving exoelectrons emanating from said sample and multiplying said exoelectrons on a point-to-point basis so that pattern information contained in said exolectrons is preserved in said multiplier; detector means in the proximity of said multiplier for receiving said multiplied electrons and yielding an output indicative of the spatial distribution of said radiation; and means for stimulating the emission of exoelectrons from said sample after the exposure of said sample to said radiation.
Claim 3
Dependent Claim
13 words
The dosimeter of claim 1 wherein said electron multiplier is a microchannel plate.
Claim 4
Dependent Claim
12 words
The dosimeter of claim 2 wherein said detector is a phosphorous screen.
Claim 5
Dependent Claim
71 words
The dosimeter of claim 3 wherein said sample, said multipliers and said screen are contained in an evacuable casing; and further including means for maintaining said sample at a reference voltage V0 which may be ground, the input electrode of said multiplier at a voltage V1, the output electrode of said multiplier at a voltage V2, and said screen at a voltage V3, where: V0 < V1 < V2 < V3.
Claim 6
Dependent Claim
26 words
The dosimeter of claim 3 wherein said means for stimulating includes heater means for raising said sample to a temperature at which maximum exoelectron emission occurs.
Claim 7
Dependent Claim
20 words
The dosimeter of claim 3 wherein said means for stimulating includes a source of electromagnetic radiation for illuminating said sample.
Claim 8
Dependent Claim
55 words
The dosimeter of claim 1 wherein said multiplier is a compound microchannel plate formed from at least two single microchannel plates, each having channels angularly disposed with respect to the input and output surfaces of said plates, said two microchannel plates being formed along a common plane and the slopes of said channels being opposite.
Claim 9
Dependent Claim
75 words
The dosimeter of claim 7 wherein said detector is a phosphorous screen: said sample, said multiplier, and said screen are contained in an evacuable casing; and further including means for maintaining said sample at a reference voltage V0, which may be ground, the input to said multiplier at a voltage V1 the output to said multiplier at a voltage V2, and said screen at a voltage V3 where: V0 < V1 < V2 < V3.
Claim 10
Dependent Claim
26 words
The dosimeter of claim 7 wherein said means for stimulating includes heater means for raising said sample to a temperature at which maximum exoelectron emission occurs.
Claim 11
Dependent Claim
20 words
The dosimeter of claim 7 wherein said means for stimulating includes a source of electromagnetic radiation for illuminating said sample.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |