US3721824A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for adjusting gain of photomultiplier type scintillation detectors
Assignee: Revvity Health Sciences Inc
•
Filing: 1967-04-10
•
Granted: 1973-03-20
•
Expires: 1987-04-10
Abstract
Abstract Photomultiplier type scintillation detectors are normalized, or adjusted to constant gain characteristics, independent of the high voltage applied to the photomultiplier. The normalized photomultiplier circuit is particularly useful in coincidence counting in liquid scintillation spectrometry, especially where the circuit is of the summation type. The inventive system has special application to apparatus for externally standardizing the spectrometer output to compensate for sample quench effects.
Inventors
- 👤 S Bristol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:59
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/20; G01T1/204; G01T1/2042; G01T1/2045
Claims Analysis
Total Claims: 132
Claim 1
Independent Claim
211 words
A method of normalizing a spectrometer having (1) a pair of photomultiplier tube circuits responsive to scintillations from radioactivity decay events for producing electrical signals proportional in amplitude to the energy of corresponding decay events, each of said circuits comprising (a) a photomultiplier having an anode, a cathode, and a sequential array of dynodes, (b) a voltage divider network interconnecting said dynodes, and (c) means for applying a high voltage across said network to establish progressively higher potentials at said dynodes relative to the cathode, (2) means for amplifying the signals from said circuit, (3) discriminator means for passing only a selected amplitude band of amplified signals therethrough, and (4) means for counting discriminated amplified signals as a measure of the activity level of a radionuclide, the improvement comprising: 1. disposing a radionuclide near each of said photomultipliers, said radionuclide having predetermined count-producing characteristics, 2. counting the counts produced by said radionuclide, and 3. adjusting each of said voltage divider networks independent of one another and independent of said high voltage to thereby independently adjust the gain of each of said photomultiplier tube circuits to produce a count substantially equal to said predetermined count so that said spectrometer is thereby compensated for changes in gain characteristics of said photomultipliers with time.
Claim 2
Independent Claim
211 words
A method of normalizing a spectrometer having (1) a pair of photomultiplier tube circuits responsive to scintillations from radioactivity decay events for producing electrical signals proportional in amplitude to the energy of corresponding decay events, each of said circuits comprising (a) a photomultiplier having an anode, a cathode, and a sequential array of dynodes, (b) a voltage divider network interconnecting said dynodes, and (c) means for applying a high voltage across said network to establish progressively higher potentials at said dynodes relative to the cathode, (2) means for amplifying the signals from said circuit, (3) discriminator means for passing only a selected amplitude band of amplified signals therethrough, and (4) means for counting discriminated amplified signals as a measure of the activity level of a radionuclide, the improvement comprising: 1. disposing a radionuclide near each of said photomultipliers, said radionuclide having predetermined count-producing characteristics, 2. counting the counts produced by said radionuclide, and 3. adjusting each of said voltage divider networks independent of one another and independent of said high voltage to thereby independently adjust the gain of each of said photomultiplier tube circuits to produce a count substantially equal to said predetermined count so that said spectrometer is thereby compensated for changes in gain characteristics of said photomultipliers with time.
Claim 3
Dependent Claim
51 words
adjusting the response of only one of said event-responsive means and then only the other of said event-responsive means to produce counts at said counting means substantially equal to said predetermined count wherein said adjustment of one of said event-responsive means is independent of the adjustment of said other event-responsive means.
Claim 4
Dependent Claim
51 words
adjusting the response of only one of said event-responsive means and then only the other of said event-responsive means to produce counts at said counting means substantially equal to said predetermined count wherein said adjustment of one of said event-responsive means is independent of the adjustment of said other event-responsive means.
Claim 5
Independent Claim
110 words
A method of normalizing a scintillation spectrometer having (1) a pair of means responsive to radioactivity decay events for producing electrical signals proportional in amplitude to the energy of corresponding decay events (2) means for amplifying the signals from said event-responsive means, (3) discriminator means for passing only a selected amplitude band of amplified signals therethrough, (4) circuit means adapted to selectively respond to simultaneous signals of both said event-responsive means or to signals of one of said event-responsive means and for delivering an output signal, and (5) means for counting said output signals as a measure of the number of said decay events, which method comprises the steps of:
Claim 6
Independent Claim
110 words
A method of normalizing a scintillation spectrometer having (1) a pair of means responsive to radioactivity decay events for producing electrical signals proportional in amplitude to the energy of corresponding decay events (2) means for amplifying the signals from said event-responsive means, (3) discriminator means for passing only a selected amplitude band of amplified signals therethrough, (4) circuit means adapted to selectively respond to simultaneous signals of both said event-responsive means or to signals of one of said event-responsive means and for delivering an output signal, and (5) means for counting said output signals as a measure of the number of said decay events, which method comprises the steps of:
Claim 7
Dependent Claim
13 words
means for applying a voltage to each of said pair of event-responsive means,
Claim 8
Dependent Claim
13 words
means for applying a voltage to each of said pair of event-responsive means,
Claim 9
Dependent Claim
10 words
means for amplifying the signals from said photomultiplier tube circuits,
Claim 10
Dependent Claim
10 words
means for amplifying the signals from said photomultiplier tube circuits,
Claim 11
Dependent Claim
8 words
counting the counts produced by said radionuclide, and
Claim 12
Dependent Claim
8 words
counting the counts produced by said radionuclide, and
Claim 13
Dependent Claim
11 words
means for applying high voltage to each of said event-responsive means,
Claim 14
Dependent Claim
11 words
means for applying high voltage to each of said event-responsive means,
Claim 15
Dependent Claim
10 words
means for amplifying the signals from each of said circuits,
Claim 16
Dependent Claim
10 words
means for amplifying the signals from each of said circuits,
Claim 17
Dependent Claim
18 words
first and second means for separately amplifying the electrical signals from said first and second photomultiplier tube means,
Claim 18
Dependent Claim
18 words
first and second means for separately amplifying the electrical signals from said first and second photomultiplier tube means,
Claim 19
Dependent Claim
21 words
first logic means responsive to simultaneous signals from said first and second photomultiplier tube means and for producing a coincidence signal,
Claim 20
Dependent Claim
21 words
first logic means responsive to simultaneous signals from said first and second photomultiplier tube means and for producing a coincidence signal,
Claim 21
Dependent Claim
14 words
means for amplifying the electrical signals from said first and second photomultiplier tube means,
Claim 22
Dependent Claim
14 words
means for amplifying the electrical signals from said first and second photomultiplier tube means,
Claim 23
Dependent Claim
21 words
first logic means responsive to simultaneous signals from said first and second photomultiplier tube means and for producing a coincidence signal,
Claim 24
Dependent Claim
21 words
first logic means responsive to simultaneous signals from said first and second photomultiplier tube means and for producing a coincidence signal,
Claim 25
Dependent Claim
21 words
means for summing the electrical signals from said first and second photomultiplier tube means and for producing a first summation signal,
Claim 26
Dependent Claim
21 words
means for summing the electrical signals from said first and second photomultiplier tube means and for producing a first summation signal,
Claim 27
Dependent Claim
13 words
discriminator means for passing only a selected amplitude band of amplified signals therethrough,
Claim 28
Dependent Claim
13 words
discriminator means for passing only a selected amplitude band of amplified signals therethrough,
Claim 29
Dependent Claim
22 words
means for summing the electrical signals from said first and said second photomultiplier tube means and for producing a first summation signal,
Claim 30
Dependent Claim
22 words
means for summing the electrical signals from said first and said second photomultiplier tube means and for producing a first summation signal,
Claim 31
Dependent Claim
22 words
discriminator means connected to at least one of said amplifying means for passing only a selected amplitude band of amplified signals therethrough,
Claim 32
Dependent Claim
22 words
discriminator means connected to at least one of said amplifying means for passing only a selected amplitude band of amplified signals therethrough,
Claim 33
Dependent Claim
11 words
means for applying the signals from each of said event-responsive means,
Claim 34
Dependent Claim
11 words
means for applying the signals from each of said event-responsive means,
Claim 35
Dependent Claim
13 words
discriminator means for passing only a selected amplitude band of amplified signals therethrough,
Claim 36
Dependent Claim
13 words
discriminator means for passing only a selected amplitude band of amplified signals therethrough,
Claim 37
Dependent Claim
4 words
A scintillation spectrometer comprising:
Claim 38
Dependent Claim
4 words
A scintillation spectrometer comprising:
Claim 39
Dependent Claim
12 words
means for amplifying signals from each of said pair of event-responsive means,
Claim 40
Dependent Claim
12 words
means for amplifying signals from each of said pair of event-responsive means,
Claim 41
Dependent Claim
57 words
adjusting each of said voltage divider networks independent of one another and independent of said high voltage to thereby independently adjust the gain of each of said photomultiplier tube circuits to produce a count substantially equal to said predetermined count so that said spectrometer is thereby compensated for changes in gain characteristics of said photomultipliers with time.
Claim 42
Dependent Claim
57 words
adjusting each of said voltage divider networks independent of one another and independent of said high voltage to thereby independently adjust the gain of each of said photomultiplier tube circuits to produce a count substantially equal to said predetermined count so that said spectrometer is thereby compensated for changes in gain characteristics of said photomultipliers with time.
Claim 43
Dependent Claim
13 words
discriminator means for passing only a selected amplitude band of amplified signals therethrough,
Claim 44
Dependent Claim
13 words
discriminator means for passing only a selected amplitude band of amplified signals therethrough,
Claim 45
Dependent Claim
16 words
means for counting discriminated amplified signals as a measure of the activity level of a radionuclide,
Claim 46
Dependent Claim
16 words
means for counting discriminated amplified signals as a measure of the activity level of a radionuclide,
Claim 47
Dependent Claim
53 words
Spectrometer of claim 3 including a plurality of discriminator means, one of said discriminator means being operative to produce counts when determining the activity level of an unknown sample and the other of said means being operative to produce counts when said radionuclide having predetermined count-producing characteristics is disposed near said event-responsive means.
Claim 48
Dependent Claim
13 words
discriminator means for passing only a selected amplitude band of amplified signals therethrough,
Claim 49
Dependent Claim
13 words
discriminator means for passing only a selected amplitude band of amplified signals therethrough,
Claim 50
Dependent Claim
28 words
circuit means for selectively responding to simultaneous signals of both said photomultiplier tube circuits or to signals of one of said circuits and for delivering an output signal,
Claim 51
Dependent Claim
28 words
circuit means for selectively responding to simultaneous signals of both said photomultiplier tube circuits or to signals of one of said circuits and for delivering an output signal,
Claim 52
Dependent Claim
13 words
discriminator means for passing only a selected amplitude band of amplified signals therethrough,
Claim 53
Dependent Claim
13 words
discriminator means for passing only a selected amplitude band of amplified signals therethrough,
Claim 54
Dependent Claim
15 words
logic means responsive to discriminated simultaneous signals from said first and said second amplifying means,
Claim 55
Dependent Claim
15 words
logic means responsive to discriminated simultaneous signals from said first and said second amplifying means,
Claim 56
Dependent Claim
7 words
means for amplifying said first summation signal,
Claim 57
Dependent Claim
7 words
means for amplifying said first summation signal,
Claim 58
Dependent Claim
11 words
means for counting selected amplified signals as a measure of radioactivity,
Claim 59
Dependent Claim
11 words
means for counting selected amplified signals as a measure of radioactivity,
Claim 60
Dependent Claim
22 words
at least one amplification-discrimination means for amplifying said summation signal and for passing only a selected band of amplified summation signals therethrough,
Claim 61
Dependent Claim
22 words
at least one amplification-discrimination means for amplifying said summation signal and for passing only a selected band of amplified summation signals therethrough,
Claim 62
Dependent Claim
16 words
second logic means responsive to simultaneous signals from said first logic means and said amplification-discrimination means,
Claim 63
Dependent Claim
16 words
second logic means responsive to simultaneous signals from said first logic means and said amplification-discrimination means,
Claim 64
Dependent Claim
50 words
means for disposing near said first and second photomultiplier tube means (i) a series of samples of known activity and varying degrees of quench, (ii) a quenched unknown sample, and (iii) a quenched unknown sample and a gamma-emitting standard, to correct for counting efficiency in said quenched unknown sample, and
Claim 65
Dependent Claim
50 words
means for disposing near said first and second photomultiplier tube means (i) a series of samples of known activity and varying degrees of quench, (ii) a quenched unknown sample, and (iii) a quenched unknown sample and a gamma-emitting standard, to correct for counting efficiency in said quenched unknown sample, and
Claim 66
Dependent Claim
13 words
discriminator means for passing only a selected band of amplified summation signals therethrough,
Claim 67
Dependent Claim
13 words
discriminator means for passing only a selected band of amplified summation signals therethrough,
Claim 68
Dependent Claim
16 words
means for counting said discriminated simultaneous signals as a measure of the activity of a radionuclide,
Claim 69
Dependent Claim
16 words
means for counting said discriminated simultaneous signals as a measure of the activity of a radionuclide,
Claim 70
Dependent Claim
30 words
circuit means adapted to selectively respond to simultaneous signals from both of said event-responsive means or to signals from one of said event-responsive means and for delivering an output signal,
Claim 71
Dependent Claim
30 words
circuit means adapted to selectively respond to simultaneous signals from both of said event-responsive means or to signals from one of said event-responsive means and for delivering an output signal,
Claim 72
Dependent Claim
17 words
means for counting said output signals as a measure of the number of said decay events, and
Claim 73
Dependent Claim
17 words
means for counting said output signals as a measure of the number of said decay events, and
Claim 74
Dependent Claim
16 words
means for counting discriminated amplified signals as a measure of the number of said decay events,
Claim 75
Dependent Claim
16 words
means for counting discriminated amplified signals as a measure of the number of said decay events,
Claim 76
Dependent Claim
21 words
means for disposing a radionuclide having predetermined count-producing characteristics near said photomultipliers, said radionuclide producing counts at said counting means, and
Claim 77
Dependent Claim
21 words
means for disposing a radionuclide having predetermined count-producing characteristics near said photomultipliers, said radionuclide producing counts at said counting means, and
Claim 78
Dependent Claim
11 words
Spectrometer of claim 3 wherein said radionuclide is a gamma-emitting nuclide.
Claim 79
Dependent Claim
26 words
means for disposing near each of said pair of event-responsive means a radionuclide having predetermined count-producing characteristics, said radionuclide producing counts at said counting means, and
Claim 80
Dependent Claim
26 words
means for disposing near each of said pair of event-responsive means a radionuclide having predetermined count-producing characteristics, said radionuclide producing counts at said counting means, and
Claim 81
Dependent Claim
52 words
means operative when said circuit means responds to signals of one of said photomultiplier tube circuits for adjusting said voltage divider network independent of said high voltage to thereby adjust the gain of said photomultiplier tube circuit to a predetermined normal gain independent of the gain of the other photomultiplier tube circuit.
Claim 82
Dependent Claim
52 words
means operative when said circuit means responds to signals of one of said photomultiplier tube circuits for adjusting said voltage divider network independent of said high voltage to thereby adjust the gain of said photomultiplier tube circuit to a predetermined normal gain independent of the gain of the other photomultiplier tube circuit.
Claim 83
Dependent Claim
19 words
means for counting output signals from said circuit means as a measure of the number of decay events, and
Claim 84
Dependent Claim
19 words
means for counting output signals from said circuit means as a measure of the number of decay events, and
Claim 85
Dependent Claim
49 words
means for adjusting each of the voltage divider networks independent of one another and independent of the high voltage applied across said networks to independently adjust the gain of said photomultiplier tube circuits and thereby produce a count at said counting means substantially equal to a predetermined normal count.
Claim 86
Dependent Claim
49 words
means for adjusting each of the voltage divider networks independent of one another and independent of the high voltage applied across said networks to independently adjust the gain of said photomultiplier tube circuits and thereby produce a count at said counting means substantially equal to a predetermined normal count.
Claim 87
Dependent Claim
15 words
means for exposing a radionuclide having predetermined count-producing characteristics to said photomultiplier tube means, and
Claim 88
Dependent Claim
15 words
means for exposing a radionuclide having predetermined count-producing characteristics to said photomultiplier tube means, and
Claim 89
Dependent Claim
20 words
A scintillation spectrometer having provisions for adjusting the gain characteristics to compensate for gain changes with respect to time comprising:
Claim 90
Dependent Claim
20 words
A scintillation spectrometer having provisions for adjusting the gain characteristics to compensate for gain changes with respect to time comprising:
Claim 91
Dependent Claim
16 words
second logic means responsive to simultaneous signals from said first logic means and said discriminator means,
Claim 92
Dependent Claim
16 words
second logic means responsive to simultaneous signals from said first logic means and said discriminator means,
Claim 93
Dependent Claim
22 words
means for adjusting the gain of one of said photomultiplier tube means independent of the gain of the other photomultiplier tube means.
Claim 94
Dependent Claim
22 words
means for adjusting the gain of one of said photomultiplier tube means independent of the gain of the other photomultiplier tube means.
Claim 95
Dependent Claim
7 words
means for counting said second simultaneous signals,
Claim 96
Dependent Claim
7 words
means for counting said second simultaneous signals,
Claim 97
Dependent Claim
21 words
an additional amplification-discrimination means for amplifying said summation signal and for passing only a selected band of amplified summation signals therethrough,
Claim 98
Dependent Claim
21 words
an additional amplification-discrimination means for amplifying said summation signal and for passing only a selected band of amplified summation signals therethrough,
Claim 99
Dependent Claim
19 words
means for counting simultaneous signals from said second logic means as a measure of the activity of a radionuclide,
Claim 100
Dependent Claim
19 words
means for counting simultaneous signals from said second logic means as a measure of the activity of a radionuclide,
Claim 101
Dependent Claim
35 words
means for adjusting the gain of each of said photomultiplier tube means independent of the other of said photomultiplier tube means to produce a count at said counting means substantially equal to said predetermined count.
Claim 102
Dependent Claim
35 words
means for adjusting the gain of each of said photomultiplier tube means independent of the other of said photomultiplier tube means to produce a count at said counting means substantially equal to said predetermined count.
Claim 103
Dependent Claim
32 words
Spectrometer of claim 6 wherein said gain adjusting means includes means for adjusting the voltage applied to at least one of said dynodes without affecting the voltage between preceding and succeeding dynodes.
Claim 104
Dependent Claim
40 words
means for adjusting each of said pair of radioactivity decay event-responsive means independent of one another and independent of the voltage applied to said event-responsive means to produce a count at said counting means substantially equal to said predetermined count.
Claim 105
Dependent Claim
40 words
means for adjusting each of said pair of radioactivity decay event-responsive means independent of one another and independent of the voltage applied to said event-responsive means to produce a count at said counting means substantially equal to said predetermined count.
Claim 106
Dependent Claim
66 words
means operative when said circuit means responds to signals of only one of said event-responsive means for adjusting the response of said event-responsive means to produce a count at said counting means substantially equal to a predetermined count wherein said adjusting means adjusts the response of one of said event-responsive means independent of the response of the other event-responsive means and independent of said high voltage.
Claim 107
Dependent Claim
66 words
means operative when said circuit means responds to signals of only one of said event-responsive means for adjusting the response of said event-responsive means to produce a count at said counting means substantially equal to a predetermined count wherein said adjusting means adjusts the response of one of said event-responsive means independent of the response of the other event-responsive means and independent of said high voltage.
Claim 108
Dependent Claim
58 words
means for disengaging one of said photomultiplier tubes and for counting amplified signals from said additional amplification-discrimination means and produced by the other tube as a measure of the gain of said one photomultiplier tube, and means for adjusting the gain of one of said photomultiplier tube means independent of the gain of the other photomultiplier tube means.
Claim 109
Dependent Claim
58 words
means for disengaging one of said photomultiplier tubes and for counting amplified signals from said additional amplification-discrimination means and produced by the other tube as a measure of the gain of said one photomultiplier tube, and means for adjusting the gain of one of said photomultiplier tube means independent of the gain of the other photomultiplier tube means.
Claim 110
Dependent Claim
31 words
Spectrometer of claim 7 wherein said voltage dividing means comprises a potentiometer connecting said preceding and succeeding dynodes, with the potentiometer slider connected to said at least one of said dynodes.
Claim 111
Dependent Claim
15 words
means for exposing a radionuclide having predetermined count-producing characteristics to said photomultiplier tube means, and
Claim 112
Dependent Claim
15 words
means for exposing a radionuclide having predetermined count-producing characteristics to said photomultiplier tube means, and
Claim 113
Dependent Claim
35 words
means for adjusting the gain of each of said photomultiplier tube means independent of the other of said photomultiplier tube means to produce a count at said counting means substantially equal to said predetermined count.
Claim 114
Dependent Claim
35 words
means for adjusting the gain of each of said photomultiplier tube means independent of the other of said photomultiplier tube means to produce a count at said counting means substantially equal to said predetermined count.
Claim 115
Dependent Claim
35 words
Spectrometer of claim 7 including means for applying a biasing potential to said at least one dynode lower than that of the preceding dynode, whereby the gain of said photomultiplier is reduced to substantially 0.
Claim 116
Dependent Claim
4 words
A scintillation spectrometer comprising:
Claim 117
Dependent Claim
4 words
A scintillation spectrometer comprising:
Claim 118
Dependent Claim
4 words
A scintillation spectrometer comprising:
Claim 119
Dependent Claim
4 words
A scintillation spectrometer comprising:
Claim 120
Dependent Claim
31 words
Spectrometer of claim 11 including amplifying means and discriminator means associated with each of said photomultiplier tube circuits, and wherein said circuit means is subsequent to said amplifying and discriminator means.
Claim 121
Dependent Claim
43 words
Spectrometer of claim 11 including means for summing the signals from said photomultiplier tube circuits and for passing the summed signals to said amplifying means, and wherein said circuit means includes a simultaneous signal responsive means prior to said amplifying and discriminator means.
Claim 122
Dependent Claim
56 words
Spectrometer of claim 11 wherein said circuit means, when responsive to signals of one of said photomultiplier tube circuits, includes two discriminator means to pass selected amplitude bands, and wherein said counting means includes means for determining the ratio of signals passed through said bands as an indication of the gain of said photomultiplier tube circuits.
Claim 123
Dependent Claim
11 words
Spectrometer of claim 14 wherein said amplitude bands are integral channels.
Claim 124
Dependent Claim
19 words
Spectrometer of claim 11 wherein said gain adjusting means is independent of the high voltage applied to said photomultiplier.
Claim 125
Dependent Claim
55 words
Spectrometer of claim 11 including means for applying a biasing potential to one of said dynodes lower than that of the preceding dynode, whereby the gain of said photomultiplier tube circuit is reduced to substantially 0. 18. A coincident-counting scintillation spectrometer for detecting and measuring the activity of a radionuclide present in a sample, compRising:
Claim 126
Dependent Claim
20 words
A summation type, coincident counting, scintillation spectrometer for detecting and measuring the activity of a radionuclide in a sample, comprising:
Claim 127
Dependent Claim
20 words
A summation type, coincident counting, scintillation spectrometer for detecting and measuring the activity of a radionuclide in a sample, comprising:
Claim 128
Dependent Claim
7 words
A scintillation spectrometer having external standardization, comprising:
Claim 129
Dependent Claim
7 words
A scintillation spectrometer having external standardization, comprising:
Claim 130
Dependent Claim
7 words
A scintillation spectrometer having external standardization, comprising:
Claim 131
Dependent Claim
7 words
A scintillation spectrometer having external standardization, comprising:
Claim 132
Dependent Claim
31 words
Spectrometer of claim 21 wherein said additional amplification-discrimination means includes two integral discrimination channels, and said counting means includes means for determining the ratio of signals from said integral discrimination channels.
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) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |