US3707632A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiation dosimeter having two ionization chambers with different ratios of neutron to gamma radiation responses
Assignee: RA Stephen and Co Ltd
•
Filing: 1970-11-30
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Granted: 1972-12-26
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Expires: 1990-11-30
Abstract
Abstract An ionization dosimeter includes two ionization chambers having different ratios of neutron radiation response to gamma radiation response. One pair of corresponding electrodes of the two chambers are connected directly together. The other pair of corresponding electrodes are coupled through a capacitance. The two chambers are electrically charged in opposite polarities so that the change in potential across the capacitance is proportional to the difference between the responses of the two chambers. The value of the coupling capacitance can be chosen so that the potential represents either the effective biological radiation dose, or the neutron radiation dose.
Inventors
- 👤 Paul Neville Cooper
- 👤 Bryan John Tymons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:51
CPC Classifications
H; H01; H01J; H01J47/00; H01J47/02; H01J47/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
144 words
In an ionization dosimeter comprising a first ionization chamber including an outer electrode and an isolated inner electrode, said chamber having a predetermined ratio of neutron radiation response to gamma radiation response, means for electrically charging said chamber in a predetermined polarity and means for measuring voltage changes between the electrodes of said chamber, the improvement which comprises: a second ionization chamber including an outer electrode and an isolated inner electrode, said second ionization chamber having a ratio of neutron radiation response to gamma radiation response different from that of said first ionization chamber; means for electrically charging said second ionization chamber with a polarity opposite to that of said first ionization chamber; means establishing a direct electrical connection between one pair of corresponding electrodes of said ionization chambers; and capacitance means electrically coupling the other pair of corresponding electrodes of said ionization chambers.
Claim 2
Dependent Claim
144 words
In an ionization dosimeter comprising a first ionization chamber including an outer electrode and an isolated inner electrode, said chamber having a predetermined ratio of neutron radiation response to gamma radiation response, means for electrically charging said chamber in a predetermined polarity and means for measuring voltage changes between the electrodes of said chamber, the improvement which comprises: a second ionization chamber including an outer electrode and an isolated inner electrode, said second ionization chamber having a ratio of neutron radiation response to gamma radiation response different from that of said first ionization chamber; means for electrically charging said second ionization chamber with a polarity opposite to that of said first ionization chamber; means establishing a direct electrical connection between one pair of corresponding electrodes of said ionization chambers; and capacitance means electrically coupling the other pair of corresponding electrodes of said ionization chambers.
Claim 3
Dependent Claim
20 words
The improvement claimed in claim 1 wherein said capacitance means comprises a capacitor connected between said remaining pair of electrodes.
Claim 4
Dependent Claim
49 words
The improvement claimed in claim 1, including an electrically conductive member electrically connected to an electrode of one said ionization chamber and electrically insulated from the corresponding electrode of the other said ionization chamber, whereby the capacitance between said conductive member and said corresponding electrode constitutes said capacitance means.
Claim 5
Dependent Claim
42 words
The improvement claimed in claim 3 wherein the inner electrode of one said ionization chamber passes into the other said chamber within which it is surrounded by but insulated from a conductive member constituting said corresponding electrode of said other ionization chamber.
Claim 6
Dependent Claim
49 words
The improvement claimed in claim 3 including a conductive casing means for said dosimeter electrically connected to said outer electrode of one said chamber, wherein insulating material separates said outer electrode of the other said chamber from said casing means and from said outer electrode of said one chamber.
Claim 7
Dependent Claim
28 words
The improvement claimed in claim 1 wherein one of said first and second ionization chambers has an internal wall coating rendering said chamber preferentially sensitive to gamma radiation.
Claim 8
Dependent Claim
28 words
The improvement claimed in claim 1 wherein one of said first and second ionization chambers has an internal wall coating rendering said chamber preferentially sensitive to neutron radiation.
Claim 9
Dependent Claim
26 words
The improvement claimed in claim 6 wherein the other of said ionization chambers has an internal wall coating rendering said chamber preferentially sensitive to neutron radiation.
Claim 10
Dependent Claim
98 words
A dosimeter in accordance with claim 1 wherein said coupling capacitance has a value Ct in accordance with the equation: where C2 is the capacitance of the chamber having the lower sensitivity to neutrons; q2 is the charge sensitivity to gamma radiation of that chamber; q2n is the charge sensitivity to neutron radiation of that chamber; q1 is the charge sensitivity to gamma radiation of the chamber which is more sensitive to neutron radiation; q1n is the charge sensitivity to neutron radiation of that chamber; and QF is the quality factor of the neutron radiation in said field.
Claim 11
Dependent Claim
31 words
A dosimeter in accordance with claim 1 wherein said coupling capacitance has a value such that said voltage change is proportional only to the neutron radiation dose received by said dosimeter.
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) | 1975-12-26 | 1976-06-26 | 1976-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-26 | 1980-06-26 | 1980-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-26 | 1984-06-26 | 1984-12-26 | $7700.00 | Window Closed / Lapsed |