US4289967A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multianode cylindrical proportional counter for high count rates
Assignee: United States Department of Energy
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Filing: 1980-05-23
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Granted: 1981-09-15
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Expires: 2000-05-23
Abstract
Abstract A cylindrical, multiple-anode proportional counter is provided for counting of low-energy photons (<60 keV) at count rates of greater than 10 5 counts/sec. A gas-filled proportional counter cylinder forming an outer cathode is provided with a central coaxially disposed inner cathode and a plurality of anode wires disposed in a cylindrical array in coaxial alignment with and between the inner and outer cathodes to form a virtual cylindrical anode coaxial with the inner and outer cathodes. The virtual cylindrical anode configuration improves the electron drift velocity by providing a more uniform field strength throughout the counter gas volume, thus decreasing the electron collection time following the detection of an ionizing event. This avoids pulse pile-up and coincidence losses at these high count rates. Conventional RC position encoding detection circuitry may be employed to extract the spatial information from the counter anodes.
Inventors
- 👤 James A. Hanson
- 👤 Manfred K. Kopp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:04
CPC Classifications
H; H01; H01J; H01J47/00; H01J47/06; H01J47/062
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
136 words
A proportional counter tube for detecting ionizing radiation comprizing: a closed cylindrical housing forming an outer cathode electrode; a cylindrical inner cathode electrode disposed coaxially within said housing and spaced from the cylinder wall of said housing to form a detection volume between said inner and outer cathodes, a plurality of uniformly spaced-apart anode electrodes disposed intermediate said inner and outer cathodes and parallel to the longitudinal axis of said cathodes; an ionizable gas filling said detection volume within said housing; and means for applying bias voltages between said outer cathodes and said plurality of anodes and said inner cathode and said plurality of anodes so that a uniform electrostatic field is provided within said detection volume thereby minimizing the electron collection time at said anodes following ionizing events within said gas filling said detection volume.
Claim 2
Dependent Claim
136 words
A proportional counter tube for detecting ionizing radiation comprizing: a closed cylindrical housing forming an outer cathode electrode; a cylindrical inner cathode electrode disposed coaxially within said housing and spaced from the cylinder wall of said housing to form a detection volume between said inner and outer cathodes, a plurality of uniformly spaced-apart anode electrodes disposed intermediate said inner and outer cathodes and parallel to the longitudinal axis of said cathodes; an ionizable gas filling said detection volume within said housing; and means for applying bias voltages between said outer cathodes and said plurality of anodes and said inner cathode and said plurality of anodes so that a uniform electrostatic field is provided within said detection volume thereby minimizing the electron collection time at said anodes following ionizing events within said gas filling said detection volume.
Claim 3
Dependent Claim
43 words
The proportional counter tube as set forth in claim 1 wherein said plurality of anodes includes a plurality of individual collector wires disposed in a uniformly spaced-apart cylindrical array at constant radius located about said inner cathode to form a virtual cylindrical anode.
Claim 4
Dependent Claim
30 words
The proportional counter of claim 2 wherein said collector wires are formed of stainless steel insulatably mounted at their respective ends in the corresponding end closures of said cylindrical housing.
Claim 5
Dependent Claim
43 words
The proportional counter of claim 2 wherein said counter is a position sensitive proportional counter and further including RC encoded pulse detection means coupled with said plurality of anodes for detecting and indicating the position of an ionizing event axially of said counter.
Claim 6
Dependent Claim
21 words
The proportional counter of claim 4 wherein said anodes are connected in common to an input of said pulse detection means.
Claim 7
Dependent Claim
19 words
The proportional counter of claim 5 wherein said anodes are connected individually to separate inputs of said detection means.
Claim 8
Dependent Claim
48 words
The proportional counter as set forth in claim 2 further including a plurality of auxiliary cathode electrodes disposed in an alternately interleaved cylindrical array with said plurality of anode wires, said cathode electrodes being electrically biased to maintain the uniformity of said electrostatic field between said anode wires.
Claim 9
Dependent Claim
32 words
The proportional counter as set forth in claim 7 wherein said auxiliary cathodes include stainless steel wires insulatably mounted at their respective ends in the corresponding end closures of said cylindrical housing.
Claim 10
Dependent Claim
28 words
The proportional counter as set forth in claim 2 wherein the diameter of said virtual cylindrical anode is approximately 1/2 the inner diameter (D) of said outer cathode.
Claim 11
Dependent Claim
30 words
The proportional counter as set forth in claim 9 wherein said plurality of anodes (N) is approximately equal to the numerical value of D, where D is specified in centimeters.
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) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |