CA2066233A1 - Apparatus for bulk material constituent content determination using pulsed neutron radiation and method employed - Google Patents
Apparatus for bulk material constituent content determination using pulsed neutron radiation and method employedInfo
- Publication number
- CA2066233A1 CA2066233A1 CA002066233A CA2066233A CA2066233A1 CA 2066233 A1 CA2066233 A1 CA 2066233A1 CA 002066233 A CA002066233 A CA 002066233A CA 2066233 A CA2066233 A CA 2066233A CA 2066233 A1 CA2066233 A1 CA 2066233A1
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- bulk material
- neutron
- constituents
- measurement
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/22—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
- G01N23/221—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material by activation analysis
- G01N23/222—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material by activation analysis using neutron activation analysis [NAA]
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2223/00—Investigating materials by wave or particle radiation
- G01N2223/07—Investigating materials by wave or particle radiation secondary emission
- G01N2223/074—Investigating materials by wave or particle radiation secondary emission activation analysis
- G01N2223/0745—Investigating materials by wave or particle radiation secondary emission activation analysis neutron-gamma activation analysis
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2223/00—Investigating materials by wave or particle radiation
- G01N2223/30—Accessories, mechanical or electrical features
- G01N2223/302—Accessories, mechanical or electrical features comparative arrangements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2223/00—Investigating materials by wave or particle radiation
- G01N2223/30—Accessories, mechanical or electrical features
- G01N2223/303—Accessories, mechanical or electrical features calibrating, standardising
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2223/00—Investigating materials by wave or particle radiation
- G01N2223/60—Specific applications or type of materials
- G01N2223/643—Specific applications or type of materials object on conveyor
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- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
- Investigating Or Analysing Biological Materials (AREA)
Abstract
ABSTRACT
An installation for determining the content of the various constituents of a bulk material using pulsed neutron irradiation.
It employs measurement apparatus 1 comprising a source of neutron irradiation and a measuring region for the gamma radiation, means 2 for providing continuous circulation of the bulk material, means for receiving the data for the resulting spectra 6 and computing means 7 enabling comparison to be made of said spectral data with data resulting from measurements carried out under identical conditions on each one of the pure constituents the presence of which is being investigated, together with readout means 8 for the averaged computed result.
Figure 1.
An installation for determining the content of the various constituents of a bulk material using pulsed neutron irradiation.
It employs measurement apparatus 1 comprising a source of neutron irradiation and a measuring region for the gamma radiation, means 2 for providing continuous circulation of the bulk material, means for receiving the data for the resulting spectra 6 and computing means 7 enabling comparison to be made of said spectral data with data resulting from measurements carried out under identical conditions on each one of the pure constituents the presence of which is being investigated, together with readout means 8 for the averaged computed result.
Figure 1.
Description
520~h~
APPARATUS FOR BULK MATERIAL CONSTITUENT CONTENT DETERMINATION
USING PULSED NEVTRON RADIATION ~ND MET~IOD EMPLOYED
The present inven-tion relates to novel measurement apparatus employing pulsed neutron radiation for determining the conten-t of the various constituents of a bulk material.
It also rela-tes to a method and an installation for determin-ing this content and employing the measurement apparatus.
The problem of-ten occurs in the mining and mineral indus-tries, for example in mines and cement works, of de-termining the content of a material as regards its various elements in order to know the composition of the raw material during continuous extraction thereof or while, for example, it is being introduced into a cement making plant. Among those lS constituents or elemen-ts whlch are the most important in cemen-t-making techniques the following can be ~entioned: Si, ~1, Fe, Ca, Mg, K, C and H.
Various procedures are known for carrying out~continuous .
analysis of a material in order to determine the content of its various constituents. As examples, we can clte, among :
~: 2 :.
~:
~ ~.
:::
APPARATUS FOR BULK MATERIAL CONSTITUENT CONTENT DETERMINATION
USING PULSED NEVTRON RADIATION ~ND MET~IOD EMPLOYED
The present inven-tion relates to novel measurement apparatus employing pulsed neutron radiation for determining the conten-t of the various constituents of a bulk material.
It also rela-tes to a method and an installation for determin-ing this content and employing the measurement apparatus.
The problem of-ten occurs in the mining and mineral indus-tries, for example in mines and cement works, of de-termining the content of a material as regards its various elements in order to know the composition of the raw material during continuous extraction thereof or while, for example, it is being introduced into a cement making plant. Among those lS constituents or elemen-ts whlch are the most important in cemen-t-making techniques the following can be ~entioned: Si, ~1, Fe, Ca, Mg, K, C and H.
Various procedures are known for carrying out~continuous .
analysis of a material in order to determine the content of its various constituents. As examples, we can clte, among :
~: 2 :.
~:
~ ~.
:::
2~233 others and limi-ting ourselves to those of most recent design, methods employing neutron irradiation or emission and which enable a defined zone, ~`orming a so-called sphere of influence produced by the emission source, to be investiga-ted using hig~ly accurate nuclear analysis techni~ues.
The simplicity of -the principles employed is another advantage of the use of neutron analysis. The source is selected so tha-t the nuclear reaction during interaction with -the element -to be analyzed -takes place in the thermal neutron energy domain with an energy that is as low as possible, the neutrons producing various types of gamma radiation notably as a result of the so-called "neutronic activation" phenomenon and by the "capture" phenomenon an example of which is the reaction:
Ca48(n, gamma)Ca49 which makes it possible to determine calcium. Generally spealcing, when neutrons collide with the target nucleus (for example Ca as mentioned above) there is an initial brief emission of prompt gamma radiation after which the radioactive isotope formed returns -to its stable state by emitting gamma ~adiation known as decay radiation. This behavior, which is typical for calcium (Ca) should no-t be considered however as characteristic for all neutron interac-tions with the various ma-terials used as a target. Detection of the -types of gamma radiation emitted b~ the isotope produced enables, firstly, ~`~
' , .,- , .. .
- : ' ' . ., '' . ;'' ; ~ ' ,:
, . ,~ ". ~ , ', , 2 ~ 3 identifica-tion of the body -that is -to be determined (by Measuring th~ energy of tlle various radia-tions emitted and the half~ e o~ the element produced) and, ~econdly, i-t enables -the bod~ to be determined by measuring -the intensity of the radiation emit-ted (number of pulses received at the detector).
In order to put the principles mentioned above into practice, numerous systems have been proposed which, at best, enable results that are uniform to be obtained by continuous operation of a neutron bombardmen-t ana]ysis installation.
~R-A-2 618 225 describes a method, appara-tus and instal-lation employing a neutron source which is activated intermit--tently at fixed periods. A gamma radiation detector counts the pho-tons only a~ter neutron emission has stopped duriny the separate periods of time corresponding respectivel~ to the capture and the neutronic activation phenomena. The di~ferent signals are numerically processed using two separate channels and the results from them are automatically combinsd. No actual taking of samples is necessary. Each application requires that the relevan-t energy bands be correctl~ defined '0 in accordance with -the elements tllat are being investigated.
The method and devices accordiny to FR-A-2 61~ 225, while nevertheless constituting progress over ~nown methods and devices, lead to difficulties which it has not yet been possible to overcome in an optimal fashion. Effectivel~, the sphere of ~nfluence prod~ced starting trom the point source -' . -.: ~ . .~.............................. . . .
' ' ' . . ` ' ' . ` ' ' . ~ ' , .
2~23~
and within which the nucl~ar reac-tion takes p-ace, is tangen-tial -to -tl~e wall of -the conical hopper used for pouring the ma-terial. Because of -this, systematic sources of error may be present which are a resul-t of the more or less permanent presence of residual heaps of material which ge-t created during emp-tying of the hopper and which, because the particles are lumped together and tend -to stick, can give rise -to sys-tema-tic errors in measuremen-t. The fact should also be mentioned that two radioac-tive isotopes can decay while emitting radiation of close or equal energy which leads to interference in -the energy area. This is the case for the reactions:
Fe56(n p)MnS6 Al27(n p)Mg27 Moreover, correct energy defini-tion of the source needs to be guaranteed: effec-tively, the "effective ac-tiva-tion cross-section'l which is directly proportional to the collision probability and hence to nuclear reaction, varies with the energy of the projec-tile neutron. If this latter has a too broad spectral distribution, the same radioactive isotope can be obtained starting from -two or several elements. Thus, to take an illustrative case:
A127(n, gamma) Si (n, p) ____> ~l ff p31 (n, ~) `~
.
, ' ' ' : ~, " ' ': ~ : ' ' - ' . . . ~ , ~
' ~ - . - . ' ~
2~2~3 Such a phenomenon, if physically present, can make it impossible to de-termine an element. Only carefully performed standardization and -the use of scanning using discrete and meaningfully distinc-t values can enable these sources of error to be eliminated.
Methods of this types are also described for example in EP-A-O 095 900, EP-A-O 171 256, AT-B-295 ~93, GB-A-2 101 304 and FR-A-] 514 030 which give rise -to systema-tic disadvantages both as regards difficul~ies in carrying out measurement as ~0 well as regarding their accuracy.
The present invention enables the disadvantages of the methods and apparatuses described in the prior art, apart from F~-~-2 618 225, to be overcome. Moreover, i-t provides an improvement to -the method and apparatus described in FR-~-2 618 225.
The present inven-tion firstly provides an appara-tus for measuring the content of the various consti-tuents of a bulk material using pulsed neutron radiation comprising an enclos-ure in which an endless belt enabling continuous passage of a ~O bulk ma-terial to be provided is adapted to travel, said enclos-ure being cons-tituted of a ma-terial the molecule of which includes a high proportion of hydrogen and containlng, on respective sides of the endless belt, a pulsed neutron rad~ation source and measurement means for the various gamma radiations produced by the bu k material const:tutiny the target for the ' I ' ' ' ' ' .. .. . . . ..
2 ~ 3 3 neutrons emit-ted by said s~uroe.
In an embodimen-t of the measuriny appara-tus, the source is covered by means for stopping or slowing down the pulsed neutrons emit-ted, consis-ting of a shield formed of a heavy metal. One can, for e~ample, use lead for this.
The invention also provides a method for determinlng the content of the various cons-ti-tuen-ts of a bulk material in which said bulk material is continuously moving and is con-veyed through an irradiation and measurement region where the various types of gamma radiation produced by saicl irradiation are measured, said method comprising supplying the spec-tral data resulting from measurement to a computing area where standard spectral data are stored resulting from measur~ments carried ou-t under iden-tical conditions for each one of said constituents, the presence of which is to be determined, in the pure state and performing numerical processing in said computing area employing a metllod consisting of dividing the measured spectrum up into energy bands and comparing the height of each segment wi-tll-the heights of the segments for eac11 one o~ the corresponding standard spectrum energy bands in order to determine, on at least part of said energy bands, values ~or each one of said contents and to deduce therefrom a resulting~average value~
~ccording to one aspect of~-the method, -the material is first made homogeneous~over the whole volume~-thereof~to be ~;
;
2 ~
investiga-ted before it en-ters -the irradia-tion and gamma radia-tion measurement zone, the particle size distribution of the ma-terial being brought to a prof:ile that i.s very close to the particle size dis-tribution of the pure cons-tituents tha-t 5 were used to obtain the s-tandard values. If necessary, this is done by successive screening operations enabling a sequence of particle layers of prede-termined mean diameter to be obtained.
According -to another aspec-t, con-tinuous determination of the content of -the various cons-tituents of a bulk material using pulsed neutron radiation is carried out by selective measurement of gamma radiation emitted that is specific to said elements, neutron emission being typically provided by a neutron generating -tube, controlled whereby neutron emission is periodically in-terrupted, the measuremen-t phases occurring during or after termina-tion of neutron emission in order to :' supply an indication of the spectra of the various types of resulting gamma radia-ti.on.
: According to another feature, continuous determination is car.ried out in a reduced sampling region, and during determination the substan-tially unvarying par-ts of the signal .
due to the environment wi-th which the neutrons are in-teracting are comple-tely eliminated only leaving a usable signal from the de-tector defining an experimental spectrum, subsequent numerical processing of which:enables the analyzed material -i "
:~
- . : , . ; . .
:~ . , .
~$2~3 content -to be determined by ma-trix computa-tion yielding, starting from the analyzed continuous e~perimental spectrum, areas of confidence relating -to -the resuL-t of said de-termin-a-tion.
~rhe invention also provides an installation for de-termining the con-tent of the various constituents of a bulk ma-terial using pulsed neutron irradia-tion employing measure-men-t appara-tus comprising a source of neutron irradiatioll and a measuring region for the various types of gamma radiation, means for providing conlinuous circula~ion of said bulk material, means for receivi.ng the da-ta for the resulting spectra and computing means enabling comparison to be made of said spectral data with data resulting from measurements carried out under identical conditions on each one of the pure constituents the pressnce of which is being investiga-ted, together with readout means for the averaged computed result.
Obviously, in order to obtain reliable results it is necessary to carry out measuremen-t on pure constituents which are in a condition where their particle sizes are practically similar~
One of the aims of the present invention is precisely that of malcing determinations of the composition of bulk material more reliable. Moreover, experience has shown that i:
it is indispensable for the forward movement of the materials being examined to have a certain deyree of analogy from the 2S structural point of view with that of a system of par-ticles of . ~
.~: ~ , . , ~ , :
:- ~ , . :
, :
~" 2~233 different sizes subjected to movemellt similar -to laminar flow.
The op-timum would be for each slice of moving material, of the same thiclcness, to possess simul-taneously the same average density, the same average par-ticle SiZP and the same linear velocity, said linear veloci-ty being readily able -to be held cons-tant. A further aim of the invention is to ma~e errors due to -the heterogeneous nature of the density distribution and par-ticle size minimal, such errors resulting from the corresponding anisotropy in the distribution of the radiati.on, -the sensor only receiving a cone thereof corresponding to a defined solid angle.
Other aims, advantages and features of the inven-tion will become more clear from a reading of the description that follows of an embodiment of the inven-tion provided by way of non-limiting example and with reference to the at-tached draw-ing in which:
- FIGURE l is a diagrammatical vlew of~an installation according -to -the invention in which the endless belt passes through the measuring apparatus according to the invention - FIGURE 2 is a cross-section on a larger scale along line Z-Z of figure l;
- FIGURE 3 is a section -throuyh the endless belt of ~igure 2, shown on an enlarged scale;
- FIGURE 4 shows the general shape of the spectra de-tected on four pure elements these being Si, Ca, Al and Fe ~ .
-:
2~23~
between 2.5 and 9 MeV;
- FIGU~E 5 shows a par-t of the spectrum obtained on a raw material the composi-tion of which is being determined and, secondly, a spectrum that has been recons-ti-tuted s-tar-ting from the spectra of pure elements; the graphs show the spectra obtained by counting between 0.5 and 2.5 MeV (left hand curves) and between 2.5 and 9 MeV ~righ-t hand curves).
~ `igure 1 is a diagrammatical view of the measuring device 1 -through which an endless belt 2 carryiny bulk ma-te-rial 3 passes, it being desired to determine the content othe various constituents of said material during travel of said bel-t 2. As it is required to carry out measurement on a layer 4 of material of preferably constant thickness, levell-ing means 5 are provided ahead of the device 1. Spectral data receiving means 6, computing means 7 enabling said spectral data to be compared with -those from standard spe~tra, and readout means for the average result are provided.
Figure 2 shows a section along plane Z-Z of figure 1 on an enlarged scale. The presen-t device 1 in which the layer 4 2n of material supported by endless belt 2 circulates, consists o~ a high-density polyethylene housing 11 forming an enclosure 1~. Polyethylene is a material whose molecule includes numerous hydro~en atoms, and the presence of said~high proportion of hydrogen atoms renders the polyethylene material capable of eliminating, through elastic difEusion, the efEect of very low : :
"" ~
2~6~2t-~3 energy ~amma rays on -the count.
The device 1 includes a neutron source 14 housed in a bo-t-tom compartment 13 and consisting of a neutron genera-tor tube loca-ted below -the movin~ endless belt 2. The device 1 ac-tually includes a region providing pulsed neu-tron radia-tion resulting from -the ac-tion of the neutrons emitted by source 14, and a gamma ray measuring region using a detector 16 which, in the presen-t case, is a counter for the gamma radia-tion emit-ted by all the elements present in the continuously moving mass 4. Detec-tor 16 is loca-ted in enclosure 12 on the opposite side of endless belt 2 ~o source 14. Screening covers source 14 in order to slow down or stop emi-tted neutrons, consistin~ of three walls 17 made of a heavy metal, for example lead. The neutrons emitted by source 14 thus pass through the moving bulk material 4, the -thickness of which is determined by a straight edge means 5.
The nominal neutron flu~c can be of the order of 10 to lO particles per second~ Detector 16 is a scintillation counter-type element employing, for e~ample, thallium-activated sodium iodide. The counter itself is associated with two pro-tective shields 18 forming oblique screens made of lead which isolate it from reflections and other spurious influences.
Figure 3 shows a cross-sec-tional view taken in the sense of travel of' the layer 4 of materlal. More precisely, that ~ ~;
, ' ' . . .: ~ - ~ , ;
, : , , ,.: ~ ' ' ' .
2~'2~
par-t of the layer which is meaningful for th~ measurement has been shown in a preferred embodimen-t of -the invention, this consists of a slab 19 about 12 cm high and about 3G cm wide.
Wi-th a throu~hput of 1 000 metric tons/hour, this type of geome-try has enabled reproducible and reliable measurements over an energy range of from O to lO ~eV -to be obtained.
De-tector 16 is linked to spectral data receiving means 6 which transmit their data -to compu-ting means 7 enabling comparisons to be made with standard data. Readou-t means 8 enable the result obtained to be displayed.
Those ele~ents which are of in-teres-t and of which it is desired to know the content in raw material are for example eight in number. Adapta-tion of the method to a different number of elements is readily accessible to those skilled in the ar-t of radio-nuclear analysis. Those elemen-ts -that are typically analyzed are, among others: Fe, Si, Ca, Al, K, C, Mg, Tl. In one embodiment, two measuremen-t channels are employed: the firs-t one takes account of gamma radiation due to capture and activa-tion phenomena, the second channel only handling activation gamma radiation. The final spectrum (number of hits per second) is obtairled from the difference, giving the capture gamma radia-tion spectrum. Teaching in this matter is provided in FR-A-2 618 225.
Obviously, if it were desired to take accoun-t of other types of gamma radiatlon, for example, those gamma rays known ~ , .
- : - . , i .... .. ~ . ~ . . .
The simplicity of -the principles employed is another advantage of the use of neutron analysis. The source is selected so tha-t the nuclear reaction during interaction with -the element -to be analyzed -takes place in the thermal neutron energy domain with an energy that is as low as possible, the neutrons producing various types of gamma radiation notably as a result of the so-called "neutronic activation" phenomenon and by the "capture" phenomenon an example of which is the reaction:
Ca48(n, gamma)Ca49 which makes it possible to determine calcium. Generally spealcing, when neutrons collide with the target nucleus (for example Ca as mentioned above) there is an initial brief emission of prompt gamma radiation after which the radioactive isotope formed returns -to its stable state by emitting gamma ~adiation known as decay radiation. This behavior, which is typical for calcium (Ca) should no-t be considered however as characteristic for all neutron interac-tions with the various ma-terials used as a target. Detection of the -types of gamma radiation emitted b~ the isotope produced enables, firstly, ~`~
' , .,- , .. .
- : ' ' . ., '' . ;'' ; ~ ' ,:
, . ,~ ". ~ , ', , 2 ~ 3 identifica-tion of the body -that is -to be determined (by Measuring th~ energy of tlle various radia-tions emitted and the half~ e o~ the element produced) and, ~econdly, i-t enables -the bod~ to be determined by measuring -the intensity of the radiation emit-ted (number of pulses received at the detector).
In order to put the principles mentioned above into practice, numerous systems have been proposed which, at best, enable results that are uniform to be obtained by continuous operation of a neutron bombardmen-t ana]ysis installation.
~R-A-2 618 225 describes a method, appara-tus and instal-lation employing a neutron source which is activated intermit--tently at fixed periods. A gamma radiation detector counts the pho-tons only a~ter neutron emission has stopped duriny the separate periods of time corresponding respectivel~ to the capture and the neutronic activation phenomena. The di~ferent signals are numerically processed using two separate channels and the results from them are automatically combinsd. No actual taking of samples is necessary. Each application requires that the relevan-t energy bands be correctl~ defined '0 in accordance with -the elements tllat are being investigated.
The method and devices accordiny to FR-A-2 61~ 225, while nevertheless constituting progress over ~nown methods and devices, lead to difficulties which it has not yet been possible to overcome in an optimal fashion. Effectivel~, the sphere of ~nfluence prod~ced starting trom the point source -' . -.: ~ . .~.............................. . . .
' ' ' . . ` ' ' . ` ' ' . ~ ' , .
2~23~
and within which the nucl~ar reac-tion takes p-ace, is tangen-tial -to -tl~e wall of -the conical hopper used for pouring the ma-terial. Because of -this, systematic sources of error may be present which are a resul-t of the more or less permanent presence of residual heaps of material which ge-t created during emp-tying of the hopper and which, because the particles are lumped together and tend -to stick, can give rise -to sys-tema-tic errors in measuremen-t. The fact should also be mentioned that two radioac-tive isotopes can decay while emitting radiation of close or equal energy which leads to interference in -the energy area. This is the case for the reactions:
Fe56(n p)MnS6 Al27(n p)Mg27 Moreover, correct energy defini-tion of the source needs to be guaranteed: effec-tively, the "effective ac-tiva-tion cross-section'l which is directly proportional to the collision probability and hence to nuclear reaction, varies with the energy of the projec-tile neutron. If this latter has a too broad spectral distribution, the same radioactive isotope can be obtained starting from -two or several elements. Thus, to take an illustrative case:
A127(n, gamma) Si (n, p) ____> ~l ff p31 (n, ~) `~
.
, ' ' ' : ~, " ' ': ~ : ' ' - ' . . . ~ , ~
' ~ - . - . ' ~
2~2~3 Such a phenomenon, if physically present, can make it impossible to de-termine an element. Only carefully performed standardization and -the use of scanning using discrete and meaningfully distinc-t values can enable these sources of error to be eliminated.
Methods of this types are also described for example in EP-A-O 095 900, EP-A-O 171 256, AT-B-295 ~93, GB-A-2 101 304 and FR-A-] 514 030 which give rise -to systema-tic disadvantages both as regards difficul~ies in carrying out measurement as ~0 well as regarding their accuracy.
The present invention enables the disadvantages of the methods and apparatuses described in the prior art, apart from F~-~-2 618 225, to be overcome. Moreover, i-t provides an improvement to -the method and apparatus described in FR-~-2 618 225.
The present inven-tion firstly provides an appara-tus for measuring the content of the various consti-tuents of a bulk material using pulsed neutron radiation comprising an enclos-ure in which an endless belt enabling continuous passage of a ~O bulk ma-terial to be provided is adapted to travel, said enclos-ure being cons-tituted of a ma-terial the molecule of which includes a high proportion of hydrogen and containlng, on respective sides of the endless belt, a pulsed neutron rad~ation source and measurement means for the various gamma radiations produced by the bu k material const:tutiny the target for the ' I ' ' ' ' ' .. .. . . . ..
2 ~ 3 3 neutrons emit-ted by said s~uroe.
In an embodimen-t of the measuriny appara-tus, the source is covered by means for stopping or slowing down the pulsed neutrons emit-ted, consis-ting of a shield formed of a heavy metal. One can, for e~ample, use lead for this.
The invention also provides a method for determinlng the content of the various cons-ti-tuen-ts of a bulk material in which said bulk material is continuously moving and is con-veyed through an irradiation and measurement region where the various types of gamma radiation produced by saicl irradiation are measured, said method comprising supplying the spec-tral data resulting from measurement to a computing area where standard spectral data are stored resulting from measur~ments carried ou-t under iden-tical conditions for each one of said constituents, the presence of which is to be determined, in the pure state and performing numerical processing in said computing area employing a metllod consisting of dividing the measured spectrum up into energy bands and comparing the height of each segment wi-tll-the heights of the segments for eac11 one o~ the corresponding standard spectrum energy bands in order to determine, on at least part of said energy bands, values ~or each one of said contents and to deduce therefrom a resulting~average value~
~ccording to one aspect of~-the method, -the material is first made homogeneous~over the whole volume~-thereof~to be ~;
;
2 ~
investiga-ted before it en-ters -the irradia-tion and gamma radia-tion measurement zone, the particle size distribution of the ma-terial being brought to a prof:ile that i.s very close to the particle size dis-tribution of the pure cons-tituents tha-t 5 were used to obtain the s-tandard values. If necessary, this is done by successive screening operations enabling a sequence of particle layers of prede-termined mean diameter to be obtained.
According -to another aspec-t, con-tinuous determination of the content of -the various cons-tituents of a bulk material using pulsed neutron radiation is carried out by selective measurement of gamma radiation emitted that is specific to said elements, neutron emission being typically provided by a neutron generating -tube, controlled whereby neutron emission is periodically in-terrupted, the measuremen-t phases occurring during or after termina-tion of neutron emission in order to :' supply an indication of the spectra of the various types of resulting gamma radia-ti.on.
: According to another feature, continuous determination is car.ried out in a reduced sampling region, and during determination the substan-tially unvarying par-ts of the signal .
due to the environment wi-th which the neutrons are in-teracting are comple-tely eliminated only leaving a usable signal from the de-tector defining an experimental spectrum, subsequent numerical processing of which:enables the analyzed material -i "
:~
- . : , . ; . .
:~ . , .
~$2~3 content -to be determined by ma-trix computa-tion yielding, starting from the analyzed continuous e~perimental spectrum, areas of confidence relating -to -the resuL-t of said de-termin-a-tion.
~rhe invention also provides an installation for de-termining the con-tent of the various constituents of a bulk ma-terial using pulsed neutron irradia-tion employing measure-men-t appara-tus comprising a source of neutron irradiatioll and a measuring region for the various types of gamma radiation, means for providing conlinuous circula~ion of said bulk material, means for receivi.ng the da-ta for the resulting spectra and computing means enabling comparison to be made of said spectral data with data resulting from measurements carried out under identical conditions on each one of the pure constituents the pressnce of which is being investiga-ted, together with readout means for the averaged computed result.
Obviously, in order to obtain reliable results it is necessary to carry out measuremen-t on pure constituents which are in a condition where their particle sizes are practically similar~
One of the aims of the present invention is precisely that of malcing determinations of the composition of bulk material more reliable. Moreover, experience has shown that i:
it is indispensable for the forward movement of the materials being examined to have a certain deyree of analogy from the 2S structural point of view with that of a system of par-ticles of . ~
.~: ~ , . , ~ , :
:- ~ , . :
, :
~" 2~233 different sizes subjected to movemellt similar -to laminar flow.
The op-timum would be for each slice of moving material, of the same thiclcness, to possess simul-taneously the same average density, the same average par-ticle SiZP and the same linear velocity, said linear veloci-ty being readily able -to be held cons-tant. A further aim of the invention is to ma~e errors due to -the heterogeneous nature of the density distribution and par-ticle size minimal, such errors resulting from the corresponding anisotropy in the distribution of the radiati.on, -the sensor only receiving a cone thereof corresponding to a defined solid angle.
Other aims, advantages and features of the inven-tion will become more clear from a reading of the description that follows of an embodiment of the inven-tion provided by way of non-limiting example and with reference to the at-tached draw-ing in which:
- FIGURE l is a diagrammatical vlew of~an installation according -to -the invention in which the endless belt passes through the measuring apparatus according to the invention - FIGURE 2 is a cross-section on a larger scale along line Z-Z of figure l;
- FIGURE 3 is a section -throuyh the endless belt of ~igure 2, shown on an enlarged scale;
- FIGURE 4 shows the general shape of the spectra de-tected on four pure elements these being Si, Ca, Al and Fe ~ .
-:
2~23~
between 2.5 and 9 MeV;
- FIGU~E 5 shows a par-t of the spectrum obtained on a raw material the composi-tion of which is being determined and, secondly, a spectrum that has been recons-ti-tuted s-tar-ting from the spectra of pure elements; the graphs show the spectra obtained by counting between 0.5 and 2.5 MeV (left hand curves) and between 2.5 and 9 MeV ~righ-t hand curves).
~ `igure 1 is a diagrammatical view of the measuring device 1 -through which an endless belt 2 carryiny bulk ma-te-rial 3 passes, it being desired to determine the content othe various constituents of said material during travel of said bel-t 2. As it is required to carry out measurement on a layer 4 of material of preferably constant thickness, levell-ing means 5 are provided ahead of the device 1. Spectral data receiving means 6, computing means 7 enabling said spectral data to be compared with -those from standard spe~tra, and readout means for the average result are provided.
Figure 2 shows a section along plane Z-Z of figure 1 on an enlarged scale. The presen-t device 1 in which the layer 4 2n of material supported by endless belt 2 circulates, consists o~ a high-density polyethylene housing 11 forming an enclosure 1~. Polyethylene is a material whose molecule includes numerous hydro~en atoms, and the presence of said~high proportion of hydrogen atoms renders the polyethylene material capable of eliminating, through elastic difEusion, the efEect of very low : :
"" ~
2~6~2t-~3 energy ~amma rays on -the count.
The device 1 includes a neutron source 14 housed in a bo-t-tom compartment 13 and consisting of a neutron genera-tor tube loca-ted below -the movin~ endless belt 2. The device 1 ac-tually includes a region providing pulsed neu-tron radia-tion resulting from -the ac-tion of the neutrons emitted by source 14, and a gamma ray measuring region using a detector 16 which, in the presen-t case, is a counter for the gamma radia-tion emit-ted by all the elements present in the continuously moving mass 4. Detec-tor 16 is loca-ted in enclosure 12 on the opposite side of endless belt 2 ~o source 14. Screening covers source 14 in order to slow down or stop emi-tted neutrons, consistin~ of three walls 17 made of a heavy metal, for example lead. The neutrons emitted by source 14 thus pass through the moving bulk material 4, the -thickness of which is determined by a straight edge means 5.
The nominal neutron flu~c can be of the order of 10 to lO particles per second~ Detector 16 is a scintillation counter-type element employing, for e~ample, thallium-activated sodium iodide. The counter itself is associated with two pro-tective shields 18 forming oblique screens made of lead which isolate it from reflections and other spurious influences.
Figure 3 shows a cross-sec-tional view taken in the sense of travel of' the layer 4 of materlal. More precisely, that ~ ~;
, ' ' . . .: ~ - ~ , ;
, : , , ,.: ~ ' ' ' .
2~'2~
par-t of the layer which is meaningful for th~ measurement has been shown in a preferred embodimen-t of -the invention, this consists of a slab 19 about 12 cm high and about 3G cm wide.
Wi-th a throu~hput of 1 000 metric tons/hour, this type of geome-try has enabled reproducible and reliable measurements over an energy range of from O to lO ~eV -to be obtained.
De-tector 16 is linked to spectral data receiving means 6 which transmit their data -to compu-ting means 7 enabling comparisons to be made with standard data. Readou-t means 8 enable the result obtained to be displayed.
Those ele~ents which are of in-teres-t and of which it is desired to know the content in raw material are for example eight in number. Adapta-tion of the method to a different number of elements is readily accessible to those skilled in the ar-t of radio-nuclear analysis. Those elemen-ts -that are typically analyzed are, among others: Fe, Si, Ca, Al, K, C, Mg, Tl. In one embodiment, two measuremen-t channels are employed: the firs-t one takes account of gamma radiation due to capture and activa-tion phenomena, the second channel only handling activation gamma radiation. The final spectrum (number of hits per second) is obtairled from the difference, giving the capture gamma radia-tion spectrum. Teaching in this matter is provided in FR-A-2 618 225.
Obviously, if it were desired to take accoun-t of other types of gamma radiatlon, for example, those gamma rays known ~ , .
- : - . , i .... .. ~ . ~ . . .
3 ~
as "inelastic", one would suitably adap-t the number of mea-surement channels.
Where two measurement channels are employed, the infor-mation is collec-ted in the form of energy band spectra which essentially depend on four parameters:
l. the neutron flow in the irradiated mass ("thermal"
neu-trons), 2. the density of -the irradiated mass, 3. water con-tent, 4. -the concentrations Ci of -the various elements i to be identified and of which it is desired to determine the content.
Figure 4 shows the spectral curves obtained for 4 pure consti-tuents: Si, Ca, Al and Fe for an energy of from 2.5 to 9 MeV. In order not -to clutter the figure, -the spectra have ` been limited to these four pure constituents; spectra ob-tained for other pure constituents are of the same type.
Figure 5 shows the energy spectral curve for a raw material in which the content of 8 components is required to be known. This firstly shows the e~perimental spectrum ob-tained on this raw material the composi-tion of which is to be determined and, secondly, superimposed -thereon, the spectrum ~:
obtalned after calculating the composition, by oombining the eight spectra for pure elements: lt will be noticed -that tbe :
computed spectrum is very close to the spectrum measured on :
:;
. - .
2 ~ 3 the raw material to such an extent -that it is even difficult -to see the differences be-tween the two spectra in figure 5 which shows them superimposed on each other. The compu-ted spectrum in fac-t approaches -the experimentally-ob-tained spec-trum by better than 5~.
Each ordi~ate NEi corresponding to an interval of energy [Ei, Ei + AEi] is a con-bined value for -the contribution of neutron impacts wi-th the cons-tituents the con-ten-t of which is to be determined. A similar si-tuation holds in each one of the 1 024 spectral analysis channels of amplitude ~Ei.
De-termination of the conten-t of the various elements contained in -the bulk material is based on a set of spectra of the type of those shown in figure 4. Where, for example it is desired to determine the content of eight elements, it will obviously be necessary to have obtained the eight spectra, all of which are different, corresponding to each one of the pure elemen-ts the content of which in the bulk material it is desired to be determined.
These spectra are recorded over a photon energy range of 0 to 10 MeV, for example on 1 024 channels (2 ). The y-axis is the number of pulses counted per channel. The spectrum obtained for a continuous1y moving material is spli-t up into 1 024 energy bands and the height of the segment of at least part of the 1 024 energy bands is determined; moreover, the ~ ~-height obtained for each standard spectrum for these same : "' ~:
-~ ~:
: ~ , : -2 ~ 3 energy bands is de-termined. Numerical analysis on a micro-compu-ter enables the required conten-ts -to be obtained; in this case the eight conten-ts required. The mathematical principle employed can be expresses by -the .+ollowing formulae expressed in matrix form, which are the basis of the numerical calculation enabling the conten-t of tlle various components contained in the moving bulk material to be calculated and, in -the example cited above, en~bling the eight contents based on 1 024 (21) energy bands to be ob-tained. Numerical processing is based on calculation using numerical analysis me-thods for equations (one per channel) of the unknowns corresponding to the contents.
These are expressed analytically by:
e = Pl tl ~ P1 t2 + Pt3 t3 + P1 t4 + P1 t5 + P1 t6 1 7 1 8 ~ = P2 t1 + P2 t2 ~ P2 t3 ~ P2 ~Il+ P2 t5-~ P~ ~6 P2 7 2 8 pl t + p2 t + P3 t ~ P4 tl + P5 t + p6 t + P7 t + P t n n 1 n 2 n 3 n I ll 5 n 6 n 7 n 8 where:
e~ is the count relating to the ~th channel selected, on the spec-trum ob-tained for the unknown material;
p~ are the various counts on each pure elem~ant spectrum numbered i in this same channel numbered ~, ; stands for the jth channel selected from 1 024 (for -this example), optionally this can be selected ra~ndomly, i is the number of elemen-ts the content of which it is : .
, ~
.
.
desired -to be known which, in the presen-t example, can have a value of from l -to 8;
ti are the con-tents;
n is any value comprised between 8 and l 024.
Although, by way of example, it has been s-tated that operation is carried out on l 024 channels or segments, it is of course possible to employ a lower number oE channels or a higher number of channels. It is essential in each case for n to be sufficiently large to enable a meaningful averaged value to be obtained. The computing means can be programmed so that -the channels can he selected at will to have a sufficiently large number to allow a meaningful average value -to be ob-tained.
The method and -the continuous determination device resulting therefrom have proved to be readily implementable industrially and the necessary manipulations, although requir-ing a high degree o~ accuracy it is true, can be learned by personnel of average skill.
The present invention is obviously not limi-ted to the 2n embodiments -that have been described and shown in the drawings but may undergo numerous variations available to those skilled in the art without this leading to a departure from the scope of the invention.
; ~ ~
-:
. : :~ ~,
as "inelastic", one would suitably adap-t the number of mea-surement channels.
Where two measurement channels are employed, the infor-mation is collec-ted in the form of energy band spectra which essentially depend on four parameters:
l. the neutron flow in the irradiated mass ("thermal"
neu-trons), 2. the density of -the irradiated mass, 3. water con-tent, 4. -the concentrations Ci of -the various elements i to be identified and of which it is desired to determine the content.
Figure 4 shows the spectral curves obtained for 4 pure consti-tuents: Si, Ca, Al and Fe for an energy of from 2.5 to 9 MeV. In order not -to clutter the figure, -the spectra have ` been limited to these four pure constituents; spectra ob-tained for other pure constituents are of the same type.
Figure 5 shows the energy spectral curve for a raw material in which the content of 8 components is required to be known. This firstly shows the e~perimental spectrum ob-tained on this raw material the composi-tion of which is to be determined and, secondly, superimposed -thereon, the spectrum ~:
obtalned after calculating the composition, by oombining the eight spectra for pure elements: lt will be noticed -that tbe :
computed spectrum is very close to the spectrum measured on :
:;
. - .
2 ~ 3 the raw material to such an extent -that it is even difficult -to see the differences be-tween the two spectra in figure 5 which shows them superimposed on each other. The compu-ted spectrum in fac-t approaches -the experimentally-ob-tained spec-trum by better than 5~.
Each ordi~ate NEi corresponding to an interval of energy [Ei, Ei + AEi] is a con-bined value for -the contribution of neutron impacts wi-th the cons-tituents the con-ten-t of which is to be determined. A similar si-tuation holds in each one of the 1 024 spectral analysis channels of amplitude ~Ei.
De-termination of the conten-t of the various elements contained in -the bulk material is based on a set of spectra of the type of those shown in figure 4. Where, for example it is desired to determine the content of eight elements, it will obviously be necessary to have obtained the eight spectra, all of which are different, corresponding to each one of the pure elemen-ts the content of which in the bulk material it is desired to be determined.
These spectra are recorded over a photon energy range of 0 to 10 MeV, for example on 1 024 channels (2 ). The y-axis is the number of pulses counted per channel. The spectrum obtained for a continuous1y moving material is spli-t up into 1 024 energy bands and the height of the segment of at least part of the 1 024 energy bands is determined; moreover, the ~ ~-height obtained for each standard spectrum for these same : "' ~:
-~ ~:
: ~ , : -2 ~ 3 energy bands is de-termined. Numerical analysis on a micro-compu-ter enables the required conten-ts -to be obtained; in this case the eight conten-ts required. The mathematical principle employed can be expresses by -the .+ollowing formulae expressed in matrix form, which are the basis of the numerical calculation enabling the conten-t of tlle various components contained in the moving bulk material to be calculated and, in -the example cited above, en~bling the eight contents based on 1 024 (21) energy bands to be ob-tained. Numerical processing is based on calculation using numerical analysis me-thods for equations (one per channel) of the unknowns corresponding to the contents.
These are expressed analytically by:
e = Pl tl ~ P1 t2 + Pt3 t3 + P1 t4 + P1 t5 + P1 t6 1 7 1 8 ~ = P2 t1 + P2 t2 ~ P2 t3 ~ P2 ~Il+ P2 t5-~ P~ ~6 P2 7 2 8 pl t + p2 t + P3 t ~ P4 tl + P5 t + p6 t + P7 t + P t n n 1 n 2 n 3 n I ll 5 n 6 n 7 n 8 where:
e~ is the count relating to the ~th channel selected, on the spec-trum ob-tained for the unknown material;
p~ are the various counts on each pure elem~ant spectrum numbered i in this same channel numbered ~, ; stands for the jth channel selected from 1 024 (for -this example), optionally this can be selected ra~ndomly, i is the number of elemen-ts the content of which it is : .
, ~
.
.
desired -to be known which, in the presen-t example, can have a value of from l -to 8;
ti are the con-tents;
n is any value comprised between 8 and l 024.
Although, by way of example, it has been s-tated that operation is carried out on l 024 channels or segments, it is of course possible to employ a lower number oE channels or a higher number of channels. It is essential in each case for n to be sufficiently large to enable a meaningful averaged value to be obtained. The computing means can be programmed so that -the channels can he selected at will to have a sufficiently large number to allow a meaningful average value -to be ob-tained.
The method and -the continuous determination device resulting therefrom have proved to be readily implementable industrially and the necessary manipulations, although requir-ing a high degree o~ accuracy it is true, can be learned by personnel of average skill.
The present invention is obviously not limi-ted to the 2n embodiments -that have been described and shown in the drawings but may undergo numerous variations available to those skilled in the art without this leading to a departure from the scope of the invention.
; ~ ~
-:
. : :~ ~,
Claims (7)
1.- An apparatus for measuring the content of the vari-ous constituents of a bulk material using pulsed neutron radiation characterized in that it comprises an enclosure in which an endless belt (2) providing continuous passage of a bulk material is adapted to travel, said enclosure being constituted of a material the molecule of which includes a high proportion of hydrogen and containing, on respective sides of the endless belt, a pulsed neutron radiation source (14) and measurement means (16) for the various gamma radiat-ions produced by the bulk material constituting the target for the neutrons emitted by said source.
2.- A measurement apparatus according to claim 1 charac-terized in that the source is covered by means for stopping or slowing down the pulsed neutrons emitted consisting of a shield formed of a heavy metal.
3.- A method for determining the content of the various constituents of a bulk material in which said bulk material is continuously moving and is conveyed through an irradiation and measurement region where the various types of gamma radiation produced by said irradiation are measured, said method being characterized in that it comprises supplying the spectral data resulting from measurement to a computing area where standard spectral data are stored resulting from measurements carried out under identical conditions for each one of constituents, the presence of which is to be determined, in the pure state and performing numerical processing in said computing area employing a method consisting of dividing the measured spect-rum up into energy bands and comparing the height of each segment with the heights of the segments for each one of the corresponding standard spectrum energy bands in order to determine, on at least part of said energy bands, values for each one of said contents and to deduce therefrom a resulting average value.
4.- A method according to claim 3, in which continuous determination of the content of the various constituents of a bulk material using pulsed neutron radiation is carried out by selective measurement of gamma radiation emitted that is specific to said elements, neutron emission being typically provided by a neutron generating tube, controlled whereby neutron emission is periodically interrupted, the measurement phases occurring during or after termination of neutron emiss-ion in order to supply an indication of the spectra of the various gamma radiations.
5.- A method according to claim 3 or 4, in which the particle size distribution of the material has a profile that is very close to the particle size distribution of the pure constituents used to obtain the standard values.
6.- A method according to any one of claims 3 to 5, in which continuous determination is carried out in a reduced sampling region, and during determination the substantially unvarying parts of the signal due to the environment with which the neutrons are interacting are completely eliminated only leaving a usable signal from the detector defining an experimental spectrum, subsequent numerical processing of which enables the analyzed material content to be determined by matrix computation yielding, starting from the analyzed continuous experimental spectrum, areas of confidence relating to the result of said determination.
7.- An installation for determining the content of the various constituents of a bulk material using pulsed neutron irradiation characterized in that it employs measurement apparatus (1) comprising a source of neutron irradiation (14) and a measuring region (16) for the various types of gamma radiation, means (2) for providing continuous circulation of said bulk material, means (6) for receiving the data for the resulting spectra and computing means (7) enabling comparison to be made of said spectral data with data resulting from measurements carried out under identical conditions on each one of the pure constituents the presence of which is being investigated, together with readout means (8) for the averaged computed result.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9009505 | 1990-07-25 | ||
| FR9009505A FR2665260A1 (en) | 1990-07-25 | 1990-07-25 | APPARATUS FOR MEASURING BY PULSED NEUTRONIC IRRADIATION OF THE CONTENT OF ITS VARIOUS CONSTITUENTS OF A BULK MATERIAL AND DETERMINATION METHOD USING THE SAME. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2066233A1 true CA2066233A1 (en) | 1992-01-26 |
Family
ID=9399090
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002066233A Abandoned CA2066233A1 (en) | 1990-07-25 | 1991-06-21 | Apparatus for bulk material constituent content determination using pulsed neutron radiation and method employed |
Country Status (12)
| Country | Link |
|---|---|
| EP (1) | EP0493545B1 (en) |
| JP (1) | JPH05508016A (en) |
| AT (1) | ATE145726T1 (en) |
| AU (1) | AU651118B2 (en) |
| BR (1) | BR9105824A (en) |
| CA (1) | CA2066233A1 (en) |
| DE (1) | DE69123337T2 (en) |
| ES (1) | ES2097212T3 (en) |
| FR (1) | FR2665260A1 (en) |
| GR (1) | GR3022690T3 (en) |
| PT (1) | PT98432B (en) |
| WO (1) | WO1992001925A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5732115A (en) * | 1993-07-09 | 1998-03-24 | Gamma-Metrics | Enhancement of measurement accuracy in bulk material analyzer |
| US5825030A (en) * | 1997-03-20 | 1998-10-20 | Gamma-Metrics | Shaping neutron energies to achieve sensitivity and uniformity of bulk material analysis |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5396071A (en) * | 1993-07-09 | 1995-03-07 | Gamma-Metrics | Modularized assembly for bulk material analyzer |
| US6657189B2 (en) * | 2001-11-07 | 2003-12-02 | Analyser Systems Ag | Maintaining measurement accuracy in prompt gamma neutron activation analyzers with variable material flow rates or material bed depth |
| FR2869107B1 (en) * | 2004-04-14 | 2006-08-04 | Sarp Ind Sa | USE OF THE NEUTRONIC ACTIVATION TECHNIQUE FOR PHYSICO-CHEMICAL CHARACTERIZATION OF THE CONSTITUENTS |
| ES2327990B1 (en) * | 2006-05-03 | 2010-08-30 | Universidad De Oviedo | METHOD AND APPLIANCE FOR FLUOR ANALYSIS, FROM MINERAL SAMPLES OR FLUOR COMPOUNDS, BY THE METHOD OF NEUTRONIC ACTIVATION. |
| DE102006033662A1 (en) * | 2006-07-20 | 2008-01-24 | Forschungszentrum Dresden - Rossendorf E.V. | Method for determining a material composition of a material sample |
| DE102007029778B4 (en) | 2007-06-21 | 2009-04-16 | Klaus Dr. Buckup | Device for the qualitative and / or quantitative detection of chemical elements in soil samples |
| WO2011143151A1 (en) * | 2010-05-10 | 2011-11-17 | Nucor Corporation | Centralized detection of radiation in multiple facilities |
| FR3024242B1 (en) * | 2014-07-22 | 2017-10-13 | Areva Mines | DEVICE AND METHOD FOR MEASURING THE RADIOACTIVITY OF A MATERIAL |
| RU2751586C2 (en) | 2017-05-31 | 2021-07-15 | Аахен Институт Фор Ньюклеар Трейнинг Гмбх | Method and device for multi-element analysis based on neutron activation, as well as application |
| DE102017111935B4 (en) | 2017-05-31 | 2019-03-14 | Aachen Institute for Nuclear Training GmbH (AINT) | Method and apparatus for multi-element analysis based on neutron activation and computer program product therefor |
| EP3410104B1 (en) | 2017-05-31 | 2020-07-01 | Aachen Institute for Nuclear Training GmbH | Method and device for multi-element analysis based on neutron activation and use |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE384736B (en) * | 1974-04-09 | 1976-05-17 | Stiftelsen Isotoptekniska Lab | WAY TO MET THE CONCENTRATION OF A COMPONENT, EXV. IRON, IN A QUANTITY OF MATERIALS AND DEVICE FOR PERFORMANCE |
| EP0007759A1 (en) * | 1978-07-21 | 1980-02-06 | United Kingdom Atomic Energy Authority | Method of and apparatus for measuring the water content of crude oil |
| US4582992A (en) * | 1984-08-10 | 1986-04-15 | Gamma-Metrics | Self-contained, on-line, real-time bulk material analyzer |
| FR2618225B1 (en) * | 1987-07-15 | 1990-03-02 | France Etat Ponts Chaussees | METHOD AND INSTALLATION FOR NEUTRONIC BOMBARD ANALYSIS OF A BULK MATERIAL FLOW. |
-
1990
- 1990-07-25 FR FR9009505A patent/FR2665260A1/en active Granted
-
1991
- 1991-06-21 CA CA002066233A patent/CA2066233A1/en not_active Abandoned
- 1991-06-21 JP JP91511378A patent/JPH05508016A/en active Pending
- 1991-06-21 EP EP91911641A patent/EP0493545B1/en not_active Expired - Lifetime
- 1991-06-21 WO PCT/FR1991/000498 patent/WO1992001925A1/en active IP Right Grant
- 1991-06-21 AT AT91911641T patent/ATE145726T1/en not_active IP Right Cessation
- 1991-06-21 DE DE69123337T patent/DE69123337T2/en not_active Expired - Fee Related
- 1991-06-21 ES ES91911641T patent/ES2097212T3/en not_active Expired - Lifetime
- 1991-06-21 BR BR919105824A patent/BR9105824A/en not_active Application Discontinuation
- 1991-06-21 AU AU80526/91A patent/AU651118B2/en not_active Ceased
- 1991-07-24 PT PT98432A patent/PT98432B/en not_active IP Right Cessation
-
1997
- 1997-02-27 GR GR970400371T patent/GR3022690T3/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5732115A (en) * | 1993-07-09 | 1998-03-24 | Gamma-Metrics | Enhancement of measurement accuracy in bulk material analyzer |
| US5825030A (en) * | 1997-03-20 | 1998-10-20 | Gamma-Metrics | Shaping neutron energies to achieve sensitivity and uniformity of bulk material analysis |
Also Published As
| Publication number | Publication date |
|---|---|
| AU8052691A (en) | 1992-02-18 |
| DE69123337D1 (en) | 1997-01-09 |
| ES2097212T3 (en) | 1997-04-01 |
| ATE145726T1 (en) | 1996-12-15 |
| EP0493545B1 (en) | 1996-11-27 |
| JPH05508016A (en) | 1993-11-11 |
| PT98432B (en) | 1999-01-29 |
| GR3022690T3 (en) | 1997-05-31 |
| AU651118B2 (en) | 1994-07-14 |
| WO1992001925A1 (en) | 1992-02-06 |
| FR2665260A1 (en) | 1992-01-31 |
| DE69123337T2 (en) | 1997-07-03 |
| FR2665260B1 (en) | 1994-12-23 |
| PT98432A (en) | 1993-09-30 |
| EP0493545A1 (en) | 1992-07-08 |
| BR9105824A (en) | 1992-08-25 |
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