US5067090A — Nuclear spectroscopy method and apparatus for dig…

Claim 1

Independent Claim 105 words

A nuclear spectroscopy method for pulse height analysis of an electrical signal containing pulses representative of nuclear particles, the amplitude of said pulses being a measure of the energy of said nuclear particles, said method comprising the following successive steps: (1) detecting said particles and forming an electrical signal containing pulses representative of said particles; (2) continuously converting said signal to digital samples, at a given rate; (3) determining whether said digital sample is representative of a pulse, and forming a digital image of each pulse; and (4) sorting said digital images into a plurality of channels according to the energy of the corresponding particles.

Claim 2

Dependent Claim 105 words

A nuclear spectroscopy method for pulse height analysis of an electrical signal containing pulses representative of nuclear particles, the amplitude of said pulses being a measure of the energy of said nuclear particles, said method comprising the following successive steps: (1) detecting said particles and forming an electrical signal containing pulses representative of said particles; (2) continuously converting said signal to digital samples, at a given rate; (3) determining whether said digital sample is representative of a pulse, and forming a digital image of each pulse; and (4) sorting said digital images into a plurality of channels according to the energy of the corresponding particles.

Claim 3

Dependent Claim 22 words

The method according to claim 1 wherein the conversion step is carried out by an analog-to-digital converter (ADC) of the flash type.

Claim 4

Dependent Claim 28 words

The method according to claim 2 wherein the processing of the digital samples is carried out with a bit range greater than the bit range of said ADC.

Claim 5

Dependent Claim 18 words

The method according to claim 2 wherein mathematical operations on said digital samples are implemented through bit shifts.

Claim 6

Dependent Claim 21 words

The method according to claim 1 wherein said determining step comprises comparing each digital sample to a predetermined threshold digital value.

Claim 7

Dependent Claim 17 words

The method according to claim 5 wherein the time of arrival of any detected pulse is recorded.

Claim 8

Dependent Claim 49 words

The method according to claim 5 including the step of determining whether a detected pulse is a stack of successive pulses close one to the other intime, by counting of the number of samples representavive of said nuclear event, and comparing said count to a predetermined maximum count value.

Claim 9

Dependent Claim 65 words

The method according to claim 1 further comprising, between converting and processing steps: (1) generating a baseline value correpsonding to a baseline signal which is free of nuclear events; (2) calculating the difference between each digital sample and said baseline value; and (3 ) comparing said difference with a predetermined threshold value so as to determine whether said digital sample is representative of a pulse.

Claim 10

Dependent Claim 34 words

The method according to claim 8 wherein said baseline value is continously updated by combining the digital sample just being generated and which is not representative of a pulse with the previous baseline value.

Claim 11

Dependent Claim 35 words

The method according to claim 9 wherein said combining step comprises making a weighted average of the sample just being generated and at least the preceding sample, both samples being not representative of a pulse.

Claim 12

Dependent Claim 36 words

The method according to claim 8 wherein, once a pulse has been detected, the energy of said pulse is calculated by summing the differences between each sample value representative of siad pulse and said baseline value.

Claim 13

Dependent Claim 44 words

The method according to claim 11 wherein, for each detected pulse, the sample just preceding the first sample representative of said pulse, as well as the sample just following the last sample representative of said pulse, are both used for said pulse energy calculation.

Claim 14

Dependent Claim 113 words

A nuclear spectroscopy logging method for determining characteristics of earth formations, comprising the steps of: (1) detecting particles coming from the formations, resulting either from natural radioactivity, or from interactions between said formations with high energy neutrons irradiating said formations; (2) converting each detected particle into an electrical signal containing pulses whose amplitude is a measure of the energy of said particle; (3) continuously converting said signal to digital samples at a given rate; (4) determining whether said digital sample is representative of a pulse, and forming a digital image of each detected pulse; and (5) sorting said digital images into a plurality of channels according to the energy of the corresponding particles.

Claim 15

Dependent Claim 113 words

A nuclear spectroscopy logging method for determining characteristics of earth formations, comprising the steps of: (1) detecting particles coming from the formations, resulting either from natural radioactivity, or from interactions between said formations with high energy neutrons irradiating said formations; (2) converting each detected particle into an electrical signal containing pulses whose amplitude is a measure of the energy of said particle; (3) continuously converting said signal to digital samples at a given rate; (4) determining whether said digital sample is representative of a pulse, and forming a digital image of each detected pulse; and (5) sorting said digital images into a plurality of channels according to the energy of the corresponding particles.

Claim 16

Dependent Claim 107 words

Nuclear spectroscopy apparatus for pulse height analysis of a n electrical signal containing pulses representative of nuclear particles, the amplitude of said pulses being a measure of the energy of said nuclear particles, said apparatus comprising: (1) means for detecting said particles and forming an electrical signal representative of said particles; (2) means for continuously converting said signal to digital samples, at a given rate; (3) means for determining whether digital sample is representative of a pulse, and forming a digital image of each nuclear pulse; and (4) means for sorting said digital images into a plurality of channels according to the energy of the corresponding particles.

Claim 17

Dependent Claim 107 words

Nuclear spectroscopy apparatus for pulse height analysis of a n electrical signal containing pulses representative of nuclear particles, the amplitude of said pulses being a measure of the energy of said nuclear particles, said apparatus comprising: (1) means for detecting said particles and forming an electrical signal representative of said particles; (2) means for continuously converting said signal to digital samples, at a given rate; (3) means for determining whether digital sample is representative of a pulse, and forming a digital image of each nuclear pulse; and (4) means for sorting said digital images into a plurality of channels according to the energy of the corresponding particles.

Claim 18

Dependent Claim 18 words

Apparatus according to claim 14 wherein said conversion means comprises an analog-to-digital converter (ADC) of the flash type.

Claim 19

Dependent Claim 28 words

Apparatus according to claim 15 wherein the processing means of the digital samples comprises digital circuits having a bit range greater than the bit range of said ADC.

Claim 20

Dependent Claim 18 words

Apparatus according to claim 16 wherein said digital circuits carry out mathematical operations on samples through bit shifts.

Claim 21

Dependent Claim 28 words

Apparatus according to claim 14 comprising means for determining whether said digital sample is representative of a pulse by comparing each digital sample to a predetermined threshold value.

Claim 22

Dependent Claim 16 words

Apparatus according to claim 18 wherein said pulse detection means include pulse arrival time detection means.

Claim 23

Dependent Claim 50 words

Apparatus according to claim 18 comprising means for determining whether a detected pulse is a stack of successive pulses close one to the other in time, including means for counting the number of samples representative of said nuclear event, and for comparing said count to a predetermined maximum count value.

Claim 24

Dependent Claim 38 words

Apparatus according to claim 18 comprising means for calculating, once a pulse has been detected, the energy of said pulse by summing the differences between each said sample which is representative of said pulse and said baseline value.

Claim 25

Dependent Claim 45 words

Apparatus according to claim 21 wherein said calculating means comprises means for including, for each detected pulse, the sample just preceding the first sample representative of said pulse, and the sample just following the last sample representative of said pulse, in said pulse energy calculation.

Claim 26

Dependent Claim 68 words

Apparatus according to claim 18 wherein said pulse determination means includes; (1) means for generating a baseline value corresponding to a baseline signal which is free of nuclear events; (2) means for calculating the difference between the digital sample and said baseline value; and (3) means for comparing said difference with a predetermined threshold value so as to determine whether said digital sample is representative of a pulse.

Claim 27

Dependent Claim 34 words

Apparatus according to claim 23 comprising means for continuously updating said baseline value by combining the digital sample just being generated and which is not representative of a pulse with the previous baseline value.

Claim 28

Dependent Claim 37 words

Apparatus according to claim 24 wherein said updating means includes means for making a weighted average of said digital sample just being generated and at least the preceding digital sample which is not representative of a pulse.

Claim 29

Dependent Claim 119 words

A nuclear spectroscopy logging apparatus for determining characteristics of earth formation, comprising: (1) means for detecting particles coming from the formations, resulting either from natural radioactivity, of from interactions between said formations with high energy neutrons irradiating said formations; (2) means for converting each detected particle into an electrical signal containing pulses whose amplitude is a measure of the energy of said particle; (3) means for continuously converting said signal to digital samples at a given rate; (4) means for determining whether said sample is representative of a pulse, and forming a digital image for each detected pulse; and (5) means for sorting said digital images into a plurality of channels according to the energy of the corresponding particles.

Claim 30

Dependent Claim 119 words

A nuclear spectroscopy logging apparatus for determining characteristics of earth formation, comprising: (1) means for detecting particles coming from the formations, resulting either from natural radioactivity, of from interactions between said formations with high energy neutrons irradiating said formations; (2) means for converting each detected particle into an electrical signal containing pulses whose amplitude is a measure of the energy of said particle; (3) means for continuously converting said signal to digital samples at a given rate; (4) means for determining whether said sample is representative of a pulse, and forming a digital image for each detected pulse; and (5) means for sorting said digital images into a plurality of channels according to the energy of the corresponding particles.

Claim 31

Dependent Claim 16 words

Apparatus according to claim 26 wherein said pulse height analysis means comprises a custom integrated circuit.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1994-11-18	1995-05-20	1995-11-19	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1998-11-18	1999-05-20	1999-11-19	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2002-11-18	2003-05-20	2003-11-19	$7700.00	Window Closed / Lapsed

Nuclear spectroscopy method and apparatus for digital pulse height analysis

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