US4177378A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Long-lived reference cell simulating the α scintillation of radon-222
Assignee: Randam Electronics Inc
•
Filing: 1978-04-24
•
Granted: 1979-12-04
•
Expires: 1998-04-24
Abstract
Abstract A reference cell simulating the light amplitude spectrum of an alpha scintillation cell containing radon 222 . The cell includes a gas-tight container having a transparent window. The interior of the container, aside from the window, has a coating of a luminescent material. Inside of the container lies an amount of radium 226 . The radium radioactively decays to produce alpha particles and radon 222 . The radon 222 and its daughter particles also undergo radioactive decay to produce further alpha particles. The 1620-year half life of the radium 226 assures an adequate supply of the radon 222 for a greater time period than radon's 3.825-day half life. The production rate of the alpha particles within the container increases for a period of approximately 22 years after the cell's construction. Although the radium 226 generally has a nonuniform distribution in the cell, the produced radon assumes a gaseous form and uniformly diffuses throughout the entire cell. The decay products of the radon 222 return to the solid state and deposit uniformly on the cell's walls. The cell may allow the alpha particles from the radium 226 to contact the luminescent material and produce light. Alternately, the cell may prevent the utilization of these alpha particles by interposing a barricade between the radium and the luminescent material. Making the cell involves coating the inside of the container with luminescent material while leaving the window clear. After placing the radium 226 inside, the cell undergoes permanent sealing against the ingress or egress of gaseous components.
Inventors
- 👤 William M. Stevens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:26
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/20; G21; G21F; G21F5/00; G21F5/015; G21G; G21G4/00; G21G4/04; Y; Y10; Y10S; Y10S250/00; Y10S250/02
Claims Analysis
Total Claims: 55
Claim 1
Independent Claim
140 words
A reference cell simulating the light spectrum of an alpha scintillation cell containing radon 222 for the purpose of calibrating electronic equipment detecting scintillations resulting from the radioactive decay of radon 222 , said cell comprising: (A) a normally closed gas-tight container formed at least partially from a substantially transparent gas-impermeable section of material; (B) a luminescent material adhered to the inside of a first portion of said container, said luminescent material not adhering to the inside of a second portion of said container, said second portion including at least a part of said transparent section of material; and (C) supply means within said container for generating (i) radon 222 ; and (ii) alpha particles, in an amount of less than about 2500 such particles per minute, in addition to those generated by said radon 222 and its decay products.
Claim 2
Dependent Claim
140 words
A reference cell simulating the light spectrum of an alpha scintillation cell containing radon 222 for the purpose of calibrating electronic equipment detecting scintillations resulting from the radioactive decay of radon 222 , said cell comprising: (A) a normally closed gas-tight container formed at least partially from a substantially transparent gas-impermeable section of material; (B) a luminescent material adhered to the inside of a first portion of said container, said luminescent material not adhering to the inside of a second portion of said container, said second portion including at least a part of said transparent section of material; and (C) supply means within said container for generating (i) radon 222 ; and (ii) alpha particles, in an amount of less than about 2500 such particles per minute, in addition to those generated by said radon 222 and its decay products.
Claim 3
Dependent Claim
21 words
The cell of claim 1 wherein said luminescent material is coated on the inside of said first portion of said container.
Claim 4
Dependent Claim
18 words
The cell of claim 2 wherein said supply means has a half life of at least five years.
Claim 5
Dependent Claim
37 words
The cell of claim 3 wherein the total number, within said container, of (i) alpha particles generated by said supply means and (ii) alpha particles produced by said radon 222 and its decay products increases with time.
Claim 6
Dependent Claim
48 words
The cell of claim 4 wherein the total number of alpha particles within said container, (i) generated by said supply means and including those produced by said radon 222 and its decay products and (ii) falling within the range of about 4.5 to 7.7 MeV., increases with time.
Claim 7
Dependent Claim
21 words
The cell of claim 5 wherein said container is totally and permanently sealed against the ingress or egress of gaseous substances.
Claim 8
Dependent Claim
53 words
The cell of claim 5 wherein said supply means is placed within said container in a position from where said alpha particles, produced in addition to those generated by said radon 222 and its decay products and travelling in a substantially straight line, can travel from said supply means to said luminescent material.
Claim 9
Dependent Claim
15 words
The cell of claim 7 wherein any radioactive substance within said container is naturally occurring.
Claim 10
Dependent Claim
62 words
The cell of claim 5 further including shield means, coupled to said container and located between said supply means and said luminescent material, for preventing alpha particles produced by said supply means, in addition to those alpha particles generated by said radon 222 and its decay products, from travelling in a substantially straight line from said supply means to said luminescent material.
Claim 11
Dependent Claim
40 words
The cell of claim 9 wherein said shield means includes a cylindrically symmetric tube open at one end and fitting inside of said container with said open end being smaller than and oriented towards said substantially transparent section of material.
Claim 12
Dependent Claim
15 words
The cell of claim 10 wherein any radioactive substance within said container is naturally occurring.
Claim 13
Dependent Claim
46 words
The cell of claim 9 wherein said shield means includes an elongated tube coupled to said container, closed at both ends, and having said supply means located at one end of said tube and openings passing through the side of said tube near the other end.
Claim 14
Dependent Claim
15 words
The cell of claim 12 wherein any radioactive substance within said cell is naturally occurring.
Claim 15
Dependent Claim
13 words
The cell of claim 5 wherein said supply means includes radium 226 .
Claim 16
Dependent Claim
135 words
The cell of claim 5 wherein said container includes: (A) a tube of metal having open ends; (B) a substantially transparent, gas-impermeable flat first section of material adhered with a gas-tight bond to said tube adjacent one of said open ends; and (C) a gas-impermeable flat second section of material, substantially similar in area and shape to said first section of material, rigidly adhered with a gas-tight bond to said tube adjacent to the other of said open ends, the flat surfaces of said first and second sections lying substantially parallel to each other and said second section being located such that a line passing perpendicular to and through the center of the flat surface of said first section of material passes through the center of the flat surface of said second section of material.
Claim 17
Dependent Claim
62 words
The cell of claim 5 wherein said container includes: (A) a tube of metal having cylindrical symmetry and open ends; (B) a substantially transparent gas-impermeable first section of material rigidly adhered to one end of said tube in a gas-tight relationship; and (C) a gas-impermeable second section of material rigidly adhered to the other end of said tube in a gas-tight relationship.
Claim 18
Dependent Claim
183 words
A reference cell simulating the light spectrum of an alpha scintillation cell, said cell comprising: (A) a normally closed gas-tight container formed at least partially from a substantially transparent gas-impermeable section of material, said container including: (1) a tube of metal having cylindrical symmetry and open ends; (2) a substantially transparent gas-impermeable first section of material rigidly adhered to one end of said tube in a gas-tight relationship; and (3) a gas-impermeable second section of material rigidly adhered to the other end of said tube in a gas-tight relationship; (B) a luminescent material coating the inside of a first portion of said container, said luminescent material not coating the inside of a second portion of said container, said second portion including at least a part of said transparent section of material; and (C) radioactive nongaseous supply means, within said container and having a first half life, for generating, by radioactive decay, a gaseous radioactive material having a second half life and undergoing radioactive decay to produce alpha particles, said first half life being at least twice as long as said second half life.
Claim 19
Dependent Claim
183 words
A reference cell simulating the light spectrum of an alpha scintillation cell, said cell comprising: (A) a normally closed gas-tight container formed at least partially from a substantially transparent gas-impermeable section of material, said container including: (1) a tube of metal having cylindrical symmetry and open ends; (2) a substantially transparent gas-impermeable first section of material rigidly adhered to one end of said tube in a gas-tight relationship; and (3) a gas-impermeable second section of material rigidly adhered to the other end of said tube in a gas-tight relationship; (B) a luminescent material coating the inside of a first portion of said container, said luminescent material not coating the inside of a second portion of said container, said second portion including at least a part of said transparent section of material; and (C) radioactive nongaseous supply means, within said container and having a first half life, for generating, by radioactive decay, a gaseous radioactive material having a second half life and undergoing radioactive decay to produce alpha particles, said first half life being at least twice as long as said second half life.
Claim 20
Dependent Claim
19 words
The cell of claim 17 wherein said supply means has a first half life of at least five years.
Claim 21
Dependent Claim
32 words
The cell of claim 18 wherein the total number of alpha particles within said container produced by said supply means, said radioactive material, and the decay products of either increases with time.
Claim 22
Dependent Claim
41 words
The cell of claim 19 wherein the total number of alpha particles (i) generated by said supply means and including those produced by said radon 222 and (ii) falling within the range of about 4.5 to 7.7 MeV. increases with time.
Claim 23
Dependent Claim
21 words
The cell of claim 20 wherein said container is totally and permanently sealed against the ingress or egress or gaseous substances.
Claim 24
Dependent Claim
53 words
The cell of claim 21 wherein said supply means is placed within said container in a position from where said alpha particles, produced in addition to those generated by said radon 222 and its decay products and travelling in a substantially straight line, can travel from said supply means to said luminescent material.
Claim 25
Dependent Claim
15 words
The cell of claim 22 wherein any radioactive substance within said container is naturally occurring.
Claim 26
Dependent Claim
62 words
The cell of claim 21 further including shield means, coupled to said container and located between said supply means and said luminescent material, for preventing alpha particles produced by said supply means, in addition to those alpha particles generated by said radon 222 and its decay products, from travelling in a substantially straight line from said supply means to said luminescent material.
Claim 27
Dependent Claim
15 words
The cell of claim 24 wherein any radioactive substance within said container is naturally occurring.
Claim 28
Dependent Claim
40 words
The cell of claim 25 wherein said shield means includes a cylindrically symmetric tube open at one end and fitting inside of said container with said open end being smaller than and oriented towards said substantially transparent section of material.
Claim 29
Dependent Claim
46 words
The cell of claim 25 wherein said shield means includes an elongated tube coupled to said container, closed at both ends, and having said supply means located at one end of said tube and openings passing through the side of said tube near the other end.
Claim 30
Dependent Claim
21 words
The cell of claim 21 wherein said first half life is at least 1000 times greater than said second half life.
Claim 31
Dependent Claim
136 words
The cell of claim 28 wherein said container includes: (A) a tube of metal having open ends; (B) a substantially transparent, gas-impermeable flat first section of material adhered with a gas-tight bond to said tube adjacent to one of said open ends; and (C) a gas-impermeable flat second section of material, substantially similar in area and shape to said first section of material, rigidly adhered with a gas-tight bond to said tube adjacent to the other of said open ends, the flat surfaces of said first and second surfaces lying substantially parallel to each other and said second section being located such that a line passing perpendicular to and through the center of the flat surface of said first section of material passes through the center of the flat surface of said second section of material.
Claim 32
Dependent Claim
13 words
The cell of claim 28 wherein said supply means includes radium 226 .
Claim 33
Dependent Claim
155 words
A reference cell simulating the light spectrum of an alpha scintillation cell containing radon 222 for the purpose of calibrating electronic equipment detecting scintillations resulting from the radioactive decay of radon 222 , said cell comprising: (A) a normally closed gas-tight container formed at least partially from a substantially transparent gas-impermeable section of material; (B) a luminescent material coating the inside of a first portion of said container, said luminescent material not coating the inside of a second portion of said container, said second portion including at least a part of said transparent section of material; and (C) radioactive material producing alpha particles, located within said container and including: (i) nongaseous radium 226 ; (ii) gaseous radon 222 distributed substantially uniformily within the interior of said container; and (iii) nongaseous decay products of radon 222 , said decay products being radioactive and distributed substantially uniformily over the inside of said first portion of said container.
Claim 34
Dependent Claim
155 words
A reference cell simulating the light spectrum of an alpha scintillation cell containing radon 222 for the purpose of calibrating electronic equipment detecting scintillations resulting from the radioactive decay of radon 222 , said cell comprising: (A) a normally closed gas-tight container formed at least partially from a substantially transparent gas-impermeable section of material; (B) a luminescent material coating the inside of a first portion of said container, said luminescent material not coating the inside of a second portion of said container, said second portion including at least a part of said transparent section of material; and (C) radioactive material producing alpha particles, located within said container and including: (i) nongaseous radium 226 ; (ii) gaseous radon 222 distributed substantially uniformily within the interior of said container; and (iii) nongaseous decay products of radon 222 , said decay products being radioactive and distributed substantially uniformily over the inside of said first portion of said container.
Claim 35
Dependent Claim
22 words
The cell of claim 31 wherein the number of alpha particles within said cell produced by said radioactive materials increases with time.
Claim 36
Dependent Claim
21 words
The cell of claim 32 wherein said container is totally and permanently sealed against the ingress or egress of gaseous substances.
Claim 37
Dependent Claim
53 words
The cell of claim 33 wherein said supply means is placed within said container in a position from where said alpha particles, produced in addition to those generated by said radon 222 and its decay products and travelling in a substantially straight line, can travel from said supply means to said luminescent material.
Claim 38
Dependent Claim
63 words
The cell of claim 33 wherein further including shield means, coupled to said container and located between said supply means and said luminescent material, for preventing alpha particles produced by said supply means, in addition to those alpha particles generated by said radon 222 and its decay products, from travelling in a substantially straight line from said supply means to said luminescent material.
Claim 39
Dependent Claim
40 words
The cell of claim 35 wherein said shield means includes a cylindrically symmetric tube open at one end and fitting inside of said container with said open end being smaller than and oriented towards said substantially transparent section of material.
Claim 40
Dependent Claim
46 words
The cell of claim 35 wherein said shield means includes an elongated tube coupled to said container, closed at both ends, and having said supply means located at one end of said tube and openings passing through the side of said tube near the other end.
Claim 41
Dependent Claim
135 words
The cell of claim 35 wherein said container includes: (A) a tube of metal having open ends; (B) a substantially transparent, gas-impermeable flat first section of material adhered with a gas-tight bond to said tube adjacent one of said open ends; and (C) a gas-impermeable flat second section of material, substantially similar in area and shape to said first section of material, rigidly adhered with a gas-tight bond to said tube adjacent to the other of said open ends, the flat surfaces of said first and second sections lying substantially parallel to each other and said second section being located such that a line passing perpendicular to and through the center of the flat surface of said first section of material passes through the center of the flat surface of said second section of material.
Claim 42
Dependent Claim
62 words
The cell of claim 35 wherein said container includes: (A) a tube of metal having cylindrical symmetry and open ends; (B) a substantially transparent gas-impermeable first section of material rigidly adhered to one end of said tube in a gas-tight relationship; and (C) a gas-impermeable second section of material rigidly adhered to the other end of said tube in a gas-tight relationship.
Claim 43
Dependent Claim
232 words
A reference cell simulating the light spectrum of an alpha scintillation cell, said cell comprising: (A) a normally closed gas-tight container formed at least partially from a substantially transparent gas-impermeable section of material, said container including: (1) a tube of metal having open ends; (2) a substantially transparent, gas-impermeable flat first section of material adhered with a gas-tight bond to said tube adjacent one of said open ends; and (3) a gas-impermeable flat second section of material, substantially similar in area and shape to said first section of material, rigidly adhered with a gas-tight bond to said tube adjacent to the other of said open ends, the flat surfaces of said first and second sections lying substantially parallel to each other and said second section being located such that a line passing perpendicular to and through the center of the flat surface of said first section of material passes through the center of the flat surface of said second section of material; (B) a luminescent material adhered to the inside of a first portion of said container, said luminescent material not adhering to the inside of a second portion of said container, said second portion including at least a part of said transparent section of material; and (C) radioactive supply means within said container for generating alpha particles, the number of alpha particles being generated by said supply means increasing with time.
Claim 44
Dependent Claim
232 words
A reference cell simulating the light spectrum of an alpha scintillation cell, said cell comprising: (A) a normally closed gas-tight container formed at least partially from a substantially transparent gas-impermeable section of material, said container including: (1) a tube of metal having open ends; (2) a substantially transparent, gas-impermeable flat first section of material adhered with a gas-tight bond to said tube adjacent one of said open ends; and (3) a gas-impermeable flat second section of material, substantially similar in area and shape to said first section of material, rigidly adhered with a gas-tight bond to said tube adjacent to the other of said open ends, the flat surfaces of said first and second sections lying substantially parallel to each other and said second section being located such that a line passing perpendicular to and through the center of the flat surface of said first section of material passes through the center of the flat surface of said second section of material; (B) a luminescent material adhered to the inside of a first portion of said container, said luminescent material not adhering to the inside of a second portion of said container, said second portion including at least a part of said transparent section of material; and (C) radioactive supply means within said container for generating alpha particles, the number of alpha particles being generated by said supply means increasing with time.
Claim 45
Dependent Claim
18 words
The cell of claim 40 wherein said supply means has a half life of at least five years.
Claim 46
Dependent Claim
21 words
The cell of claim 41 wherein said luminescent material is coated on the inside of said first portion of said container.
Claim 47
Dependent Claim
48 words
The cell of claim 42 wherein the total number of alpha particles within said containers, (i) generated by said supply means and including those produced by said radon 222 and its decay products and (ii) falling within the range of about 4.5 to 7.7 MeV., increases with time.
Claim 48
Dependent Claim
21 words
The cell of claim 43 wherein said container is totally and permanently sealed against the ingress or egress of gaseous substances.
Claim 49
Dependent Claim
15 words
The cell of claim 44 wherein any radioactive substance within said container is naturally occurring.
Claim 50
Dependent Claim
53 words
The cell of claim 45 wherein said supply means is placed within said container in a position from where said alpha particles, produced in addition to those generated by said radon 222 and its decay products and travelling in a substantially straight line, can travel from said supply means to said luminescent material.
Claim 51
Dependent Claim
62 words
The cell of claim 45 further including shield means, coupled to said container and located between said supply means and said luminescent material, for preventing alpha particles produced by said supply means, in addition to those alpha particles generated by said radon 222 and its decay products, from travelling in a substantially straight line from said supply means to said luminescent material.
Claim 52
Dependent Claim
40 words
The cell of claim 47 wherein said shield means includes a cylindrically symmetric tube open at one end and fitting inside of said container with said open end being smaller than and oriented towards said substantially transparent section of material.
Claim 53
Dependent Claim
46 words
The cell of claim 47 wherein said shield means includes an elongated tube coupled to said container, closed at both ends, and having said supply means located at one end of said tube and openings passing through the side of said tube near the other end.
Claim 54
Dependent Claim
13 words
The cell of claim 45 wherein said supply means includes radium 226 .
Claim 55
Dependent Claim
62 words
The cell of claim 50 wherein said container includes: (A) a tube of metal having cylindrical symmetry and open ends; (B) a substantially transparent gas-impermeable first section of material rigidly adhered to one end of said tube in a gas-tight relationship; and (C) a gas-impermeable second section of material rigidly adhered to the other end of said tube in a gas-tight relationship.
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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) | 1982-12-03 | 1983-06-04 | 1983-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-03 | 1987-06-04 | 1987-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-03 | 1991-06-04 | 1991-12-04 | $7700.00 | Window Closed / Lapsed |