EP1493045A2 - Method and device for promptly conducting non-destructive chemical analysis of test objects - Google Patents

Method and device for promptly conducting non-destructive chemical analysis of test objects

Info

Publication number
EP1493045A2
EP1493045A2 EP03729816A EP03729816A EP1493045A2 EP 1493045 A2 EP1493045 A2 EP 1493045A2 EP 03729816 A EP03729816 A EP 03729816A EP 03729816 A EP03729816 A EP 03729816A EP 1493045 A2 EP1493045 A2 EP 1493045A2
Authority
EP
European Patent Office
Prior art keywords
photon
measurement object
photon energy
energy spectrum
characteristic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP03729816A
Other languages
German (de)
French (fr)
Inventor
Stefan RÖTTGER
Uwe Keyser
Annette RÖTTGER
Andreas Zimbal
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bundesrepublik Deutschland
Original Assignee
Bundesrepublik Deutschland
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bundesrepublik Deutschland filed Critical Bundesrepublik Deutschland
Publication of EP1493045A2 publication Critical patent/EP1493045A2/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K5/00—Irradiation devices
    • G21K5/02—Irradiation devices having no beam-forming means
    • 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
    • G01N23/02—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 transmitting the radiation through the material
    • G01N23/025—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 transmitting the radiation through the material using neutrons
    • 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]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/10—Nuclear fusion reactors

Definitions

  • the invention relates to a method for the non-destructive chemical analysis of measurement objects by irradiating the measurement object with neutrons generated by target-free fusion of concentrically accelerated deuterium ions and measuring the amount of gamma photon radiation emitted promptly during the irradiation from the number of gamma photon quanta and the like respective photon energy for recording a photon energy spectrum.
  • the invention further relates to a device for the non-destructive chemical analysis of measurement objects with a neutron source for briefly irradiating the measurement object with neutrons generated by target-free fusion of concentrically accelerated deuterium ions and with at least one photon detector aimed at the measurement object for measuring the immediately after irradiation of the Measurement object promptly emitted the amount of gamma photon radiation from the number of gamma photon quanta and the respective photon energy.
  • WO 01 / 07888A2 and US Pat. No. 5,539,788 disclose the neutron activation analysis as a nuclear physical analysis method, with a small part due to the irradiation of stable nuclides with neutrons artificial radioactive nuclides are generated. During the subsequent beta decay of the generated nuclides, electrons are emitted and the gamma spectrum of the neutron-activated material to be analyzed is measured. Element concentrations can be determined very precisely from the gamma spectrum.
  • the neutron activation analysis disadvantageously requires a high required neutron density in or on a reactor core and, in connection with this, a strong activation of the measurement object.
  • stable elements with the exception of the last stable isotope and if the half-life is sufficiently long cannot be detected, since these are converted into another isotope or element after activation of a neutron.
  • Tsahi Gozani Novel applications of fast neutron interrogation methods in: Nuclear Instruments & Methods in Physics Research A 353 (1994) 635 to 640 describes a method for ⁇ -spectral analysis of luggage with a neutron activation analysis using 14 MeV neutrons.
  • spectra are examined that are based on the nuclear reactions with the formation of new radionuclides or isomers due to neutron activation.
  • a photon energy spectrum (n, ⁇ spectrum) is measured from the number of photon quanta per photon energy and the molar mass of the silicon sphere is determined from the emitted photon radiation energy.
  • n, ⁇ spectrum is measured from the number of photon quanta per photon energy and the molar mass of the silicon sphere is determined from the emitted photon radiation energy.
  • Destructive analysis methods are conventionally used for the chemical analysis of measurement objects to determine the elements and / or isotopes. When measuring, therefore, only samples can be examined for the presence of individual elements or isotopes in a relatively complex manner.
  • the object of the invention was therefore to create an improved method for the non-destructive chemical analysis of measurement objects, with which all elements and / or isotopes present in a measurement object can be determined very easily and quickly.
  • Quantities of photon radiation of the entire photon energy spectrum at least up to the range of 12 MeV and
  • Determining the elements and / or isotopes of the measurement object by assigning the characteristic photon energies distributed over the entire photon energy spectrum to corresponding elements and / or isotopes that are clearly stored in each case to form a photon energy.
  • the method has the advantage that all isotopes occurring in nature can be detected.
  • the measurement object only has to be irradiated without the need for prior sample preparation.
  • the sample geometry and the physical state of the measurement object are also arbitrary.
  • the photon energy spectrum corresponds to a recorded light frequency spectrum.
  • a quantitative determination of the chemical composition of the measurement object can preferably be carried out by measuring the complete measurable range of the gamma-photon energy spectrum and determining the proportions of the specific elements and / or isotopes by relating the amount of gamma-photon radiation per element and / or isotope to the total for all characteristic gamma-photon radiation amount determined.
  • the number of photon quanta of the individual characteristic photon energies, which protrude as pulse peaks from the curve of the recorded photon energy spectrum, are thus standardized, and the percentage distribution of the elements or isotopes determined over the entire mass of the measurement object can be calculated in a simple manner.
  • the amounts of photon radiation are preferably determined, for example, using known methods for processing measurement curves by determining the areas of the characteristic pulse curves of the photon energy spectrum at the regions of the characteristic photon energies. The pulse peaks projecting beyond the base curve of the photon energy spectrum are thus recognized and the areas under these pulse peaks are calculated.
  • a base photon energy spectrum of the measurement space is preferably recorded without the measurement object, and a photon energy spectrum used for evaluation is calculated from the difference between the photon energy spectrum recorded for analysis and the base photon energy spectrum. It is particularly advantageous to irradiate sections of the measurement object from several directions and to evaluate the multiple measurement results for a location-dependent analysis of the measurement object. In this way, the measurement object is scanned comparable to a tomography device and provides a three-dimensional spatial resolution of the isotope or element concentration.
  • the measuring objects Due to the short irradiation times and the low required energy of the thermal neutrons of E ⁇ 25 meV, the measuring objects are not adversely affected, so that the method can also be used for examining living objects, for example.
  • the object is further achieved by the generic device in that the neutron source is a neutron generator arranged next to the measurement object.
  • An evaluation computing unit is coupled to the at least one photon detector, which unit is used to determine characteristic photon energies from the gamma-photon radiation amounts of the photon energy spectrum going beyond a basic photon radiation and to determine the elements and / or isotopes of the measurement object by assigning the characteristic photon energies to the corresponding photon energy stored elements and / or isotopes is formed.
  • the at least one photon detector is shielded with means for absorbing neutrons. In this way, the scattering influence of photons that are not emitted by the measurement object can be reduced and the photon detector can be aligned as precisely as possible with the measurement object.
  • a focusing element is preferably provided between the neutron generator and the measurement object, which is designed for thermal adaptation of the neutrons.
  • the neutron velocity is adapted, for example, to the Brownian movement of the air, so that thermal neutrons are almost exclusively present in the neutron beam.
  • the focusing element can be designed, for example, as a neutron-absorbing plate with a passage bore.
  • a suitable material for the shielding of the neutron detector and the focusing element are all materials with a high neutron entrance cross section.
  • FIG. 1 shows a basic block diagram of the method according to the invention for non-destructive chemical analysis
  • Fig. 2 is a schematic representation of the immersion of a neutron in an atomic nucleus and the emission of gamma-photon energy
  • Fig. 4 - a block diagram of a device according to the invention for non-destructive chemical analysis.
  • FIG. 1 shows a schematic block diagram of the method according to the invention for the non-destructive chemical analysis of measurement objects 1.
  • the measurement object 1 is briefly or continuously irradiated with neutrons n, which are arranged in the vicinity of the measurement object 1, and which each immerse into the atomic nuclei.
  • neutrons n which are arranged in the vicinity of the measurement object 1, and which each immerse into the atomic nuclei.
  • gamma-photon energy E ⁇ is emitted.
  • a part of the emitted gamma photon quanta is measured with a gamma photon detector 3 and sent to an evaluation computing unit 5 via measuring electronics 4 known per se.
  • a photon energy spectrum 6 is first recorded there in the step of data acquisition D by plotting the number N of photon quanta over the respective photon energy E ⁇ .
  • characteristic photon energies E ⁇ are determined as the amount of gamma-photon radiation in the photon energy spectrum 6 going beyond a basic photon radiation, by detecting the pulse peaks, for example, by means of known signal curve evaluation methods.
  • the elements and / or isotopes present in the measurement object 1 are then determined from the characteristic photon energies E ⁇ by assignment to the corresponding known elements and / or isotopes that are clearly stored in each case to a photon energy.
  • the areas below the characteristic pulse curves of the photon energy spectrum are determined at the regions of the characteristic photon energies E ⁇ .
  • the proportions of the elements in the total mass of the measurement object 1 can then be determined very precisely, since the recorded photon energy spectrum 6 takes into account all known elements and / or isotopes.
  • a complete chemical analysis of the measurement object 1 can thus be carried out with a single measurement, without the measurement object 1 having to be prepared or an examination being necessary for the presence of individual elements or isotopes.
  • FIG. 2 shows the basic physical principle on which the method is based in a schematic representation.
  • the prompt process shown lasts at most 10 "17 seconds from the immersion of the neutron in the atomic nucleus.
  • FIG. 3 shows an exemplary gamma photon energy spectrum recorded with the method with characteristic pulse curves at characteristic photon energies of 380.99 keV, 393.65 keV, 41 1, 80 keV, 418.59 keV, 440.08 keV and 444, 15 keV detect.
  • the number of photons N is determined from the areas below these characteristic pulse curves.
  • FIG. 4 shows a block diagram of a device according to the invention for non-destructive chemical analysis of a measurement object 1.
  • the neutron beam n is directed to the measurement object 1.
  • a neutron moderator 7 for adapting the neutron speed to generate thermal neutrons n, which are adapted to the Brownian movement of the air
  • a focusing means 8 for focusing the neutron beam n:
  • Adjacent to the measurement object 1 is a gamma photon detector 3, which is aligned with the measurement object 1 and is designed to record a photon energy spectrum. With the aid of a multi-channel measurement, the number of photon quanta as a function of the respective photon energy E ⁇ or the light frequency v of the photons is measured and fed to an evaluation computing unit 5.
  • the at least one photon detector 3 is laterally provided with a shield 9 in order to reduce the effects of interference radiation.
  • Suitable materials for the neutron moderator 7, the focusing means 8 and the shielding 9 are all materials with a small atomic number and a small cross-section, for example polyethylene, which is mixed with a catalyst.
  • the focusing means 7 is designed, for example, as a plate with a hole.
  • the evaluation computing unit 5 is designed, for example, in terms of program technology to determine the characteristic photon energies E ⁇ from the photon radiation quantities of the photon energy spectrum that go beyond a basic photon radiation by means of signal analysis.
  • the evaluation computing unit 5 accesses a stored table 10 in which the characteristic photon energies E ⁇ of all known isotopes and thus also of the elements are stored.
  • By correlating the determined Characteristic photon energies E ⁇ with the photon energies E ⁇ for the isotopes stored in Table 10 can now be clearly concluded from the photon energy spectrum on the chemical composition of the measurement object 1.
  • the proportion of the individual isotopes in the total mass under consideration can also be determined with high precision.
  • the measurement object 1 is scanned with the aid of a three-dimensional measurement, so that a location analysis can be carried out similarly to a tomography method.
  • the invention can preferably be used wherever a qualitative and / or quantitative isotope or element detection of samples of any physical state and any geometry is concerned. This is particularly the case for the prospection of raw materials, material analysis, quality control and quality assurance, in the investigative and forensic area (preservation of evidence, evidence of evidence), the detection of weapons and explosives at airports, as well as pure substance analysis in the chemical industry.

Landscapes

  • Physics & Mathematics (AREA)
  • 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)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)

Abstract

The invention relates to a method for conducting non-destructive chemical analysis of test objects (1) by irradiating the test object (1) with neutrons and measuring the quantity of gamma photon radiation, which is emitted by the test object (1) immediately after irradiation, based on the number of gamma photon quanta of the respective photon energy (E<) in order to record a photon energy spectrum (6). The inventive method has the following steps: determining characteristic photon energies (E?) based on the gamma photon radiation quantities of the photon energy spectrum (6) which exceed a background photon radiation, and; determining the elements and/or isotopes of the test object (1) by assigning the characteristic photon energies (E?) to corresponding elements and/or isotopes that are each stored distinctly at a photon energy (E?).

Description

Verfahren und Einrichtung zur prompten zerstörungsfreien chemischen Analyse von MessobjektenMethod and device for prompt non-destructive chemical analysis of measurement objects
Die Erfindung betrifft ein Verfahren zur zerstörungsfreien chemischen Analyse von Messobjekten durch Bestrahlen des Messobjektes mit durch targetfreie Fusion von konzentrisch beschleunigten Deuterium-Ionen generierten Neutronen und Messen der während der Bestrahlung von dem Messobjekt prompt emittierten Gamma-Photonenstrahlungsmenge aus der Anzahl von Gamma-Photonenquanten und der jeweiligen Photonenenergie zum Aufnehmen eines Photonenenergiespektrums.The invention relates to a method for the non-destructive chemical analysis of measurement objects by irradiating the measurement object with neutrons generated by target-free fusion of concentrically accelerated deuterium ions and measuring the amount of gamma photon radiation emitted promptly during the irradiation from the number of gamma photon quanta and the like respective photon energy for recording a photon energy spectrum.
Die Erfindung betrifft ferner eine Einrichtung zur zerstörungsfreien chemischen Analyse von Messobjekten mit einer Neutronenquelle zum kurzzeitigen Bestrahlen des Messobjektes mit durch targetfreie Fusion von konzentrisch beschleunigten Deuterium-Ionen generierten Neutronen und mit mindestens einem auf das Messobjekt ausgerichteten Photonendetektor zum Messen der unmittelbar nach dem Bestrahlen von dem Messobjekt prompt emittierten Gamma-Photonenstrahlungsmenge aus der Anzahl von Gamma- Photonenquanten und der jeweiligen Photonenenergie.The invention further relates to a device for the non-destructive chemical analysis of measurement objects with a neutron source for briefly irradiating the measurement object with neutrons generated by target-free fusion of concentrically accelerated deuterium ions and with at least one photon detector aimed at the measurement object for measuring the immediately after irradiation of the Measurement object promptly emitted the amount of gamma photon radiation from the number of gamma photon quanta and the respective photon energy.
Zur Element- und Konzentrationsbestimmung ist beispielsweise aus der WO 01/07888A2 und dem US-Patent 5,539,788 die Neutronenaktivierungsanalyse als kernphysikalisches Analyseverfahren bekannt, wobei durch Bestrahlung stabiler Nuklide mit Neutronen zu einem geringen Teil künstliche radioaktive Nuklide erzeugt werden. Bei dem anschließenden Beta-Zerfall der erzeugten Nuklide werden Elektronen ausgesandt und das Gamma-Spektrum des neutronenaktivierten zu analysierenden Materials gemessen. Aus dem Gamma-Spektrum können Elementkonzentrationen sehr genau bestimmt werden. Bei der Neutronenaktivierungsanalyse ist nachteilig jedoch eine hohe erforderliche Neutronendichte in oder an einem Reaktorkern und damit verbunden eine starke Aktivierung des Messobjektes erforderlich. Zudem lassen sich stabile Elemente mit Ausnahme des letzten stabilen Isotops und wenn die Halbwertzeit ausreichend lang ist nicht nachweisen, da sich diese nach Aufnahme eines Neutrons bei der Aktivierung in ein anderes Isotop oder Element umwandeln.For the determination of elements and concentrations, for example, WO 01 / 07888A2 and US Pat. No. 5,539,788 disclose the neutron activation analysis as a nuclear physical analysis method, with a small part due to the irradiation of stable nuclides with neutrons artificial radioactive nuclides are generated. During the subsequent beta decay of the generated nuclides, electrons are emitted and the gamma spectrum of the neutron-activated material to be analyzed is measured. Element concentrations can be determined very precisely from the gamma spectrum. However, the neutron activation analysis disadvantageously requires a high required neutron density in or on a reactor core and, in connection with this, a strong activation of the measurement object. In addition, stable elements with the exception of the last stable isotope and if the half-life is sufficiently long cannot be detected, since these are converted into another isotope or element after activation of a neutron.
Verfahren zur Analyse von Substanzen mit Hilfe einer Neutronen- Aktivierungsanalyse sind beispielsweise in dem US-Patent 5,982,838 und der DE 197 45 669 A1 beschrieben. Hierbei werden durch Linienzuordnung und Flächenberechnung aus bestimmten Energieregionen des aufgenommenen Energiespektrums bestimmt.Methods for analyzing substances using a neutron activation analysis are described, for example, in US Pat. No. 5,982,838 and DE 197 45 669 A1. Here are determined by line assignment and area calculation from certain energy regions of the recorded energy spectrum.
In Tsahi Gozani: Novel applications of fast neutron interrogation methods in: Nuclear Instruments & Methods in Physics Research A 353 ( 1994) 635 bis 640 ist ein Verfahren zur γ-Spektralanalyse von Gepäckstücken mit einer NeutronenAktivierungsanalyse unter Verwendung von 14 MeV Neutronen beschrieben. Auch hier werden Spektren untersucht, die auf den Kernreaktionen mit Bildung neuer Radionuklide oder Isomere aufgrund der Neutronenaktivierung basieren.Tsahi Gozani: Novel applications of fast neutron interrogation methods in: Nuclear Instruments & Methods in Physics Research A 353 (1994) 635 to 640 describes a method for γ-spectral analysis of luggage with a neutron activation analysis using 14 MeV neutrons. Here too, spectra are examined that are based on the nuclear reactions with the formation of new radionuclides or isomers due to neutron activation.
Zur Bestimmung der Verunreinigung einer Siliziumkugel ist aus A. Paul, S. Röttger, A. Zimbal und U. Keyser: „Prompt (n, γ) Mass Measurements for the AVOGADRO Projeet" in: Hyperfine Interactions 132: 189-194, 2001 bekannt, eine zu untersuchende Siliziumprobe am Ende eines gekrümmten Neutronenleiters in großem Abstand von einem Reaktorkern den parallelen Strahl thermischer Neutronen einer bekannten Flussdichte (E < 25 meV) auszusetzen. In der Materialprobe werden die thermischen Neutronen eingefangen und bewirken eine sehr hohe innere Anregung der betroffenen Atomkerne. Hieraus resultiert die sofortige Umordnung der Nukleonen in den neuen, energetisch günstigsten Zustand. Die überschüssige Energie wird durch die prompte Emission elektromagnetischer Strahlung in Form charakteristischer Photonenquanten abgegeben. Aus der Anzahl der Photonenquanten pro Photonenenergie wird ein Photonenenergiespektrum (n, γ - Spektrum) gemessen und die molare Masse der Siliziumkugel aus der emittierten Photonenstrahlungsenergie bestimmt. Eine chemische Analyse des Messobjekts erfolgt jedoch nicht.From A. Paul, S. Röttger, A. Zimbal and U. Keyser to determine the contamination of a silicon ball: "Prompt (n, γ) Mass Measurements for the AVOGADRO Projeet" in: Hyperfine Interactions 132: 189-194, 2001 known to expose a silicon sample to be examined at the end of a curved neutron guide at a large distance from a reactor core to the parallel beam of thermal neutrons of a known flux density (E <25 meV). The thermal neutrons are captured in the material sample and cause a very high internal excitation of the affected atomic nuclei. This results in the immediate rearrangement of the nucleons in the new, energetically most favorable state. The excess energy is given off by the prompt emission of electromagnetic radiation in the form of characteristic photon quanta. A photon energy spectrum (n, γ spectrum) is measured from the number of photon quanta per photon energy and the molar mass of the silicon sphere is determined from the emitted photon radiation energy. However, there is no chemical analysis of the measurement object.
Zur chemischen Analyse von Messobjekten zur Bestimmung der Elemente und/oder Isotope werden herkömmlicherweise zerstörende Analysemethoden eingesetzt. Bei der Messung können daher nur Proben relativ aufwendig auf das Vorhandensein einzelner Elemente bzw. Isotope untersucht werden.Destructive analysis methods are conventionally used for the chemical analysis of measurement objects to determine the elements and / or isotopes. When measuring, therefore, only samples can be examined for the presence of individual elements or isotopes in a relatively complex manner.
Aufgabe der Erfindung war es daher, ein verbessertes Verfahren zur zerstörungsfreien chemischen Analyse von Messobjekten zu schaffen, mit dem sehr einfach und schnell möglichst alle in einem Messobjekt vorhandenen Elemente und/oder Isotope bestimmt werden können.The object of the invention was therefore to create an improved method for the non-destructive chemical analysis of measurement objects, with which all elements and / or isotopes present in a measurement object can be determined very easily and quickly.
Die Aufgabe wird mit dem gattungsgemäßen Verfahren erfindungsgemäß gelöst durch Ermitteln von charakteristischen Photonenenergien aus den über eine Grundphotonenstrahlung hinausgehenden Gamma-The object is achieved according to the invention with the generic method Determination of characteristic photon energies from the gamma that go beyond basic photon radiation
Photonenstrahlungs-mengen des gesamten Photonenenergiespektrums mindestens bis zum Bereich von 12 MeV undQuantities of photon radiation of the entire photon energy spectrum at least up to the range of 12 MeV and
Bestimmen der Elemente und/oder Isotope des Messobjektes durch Zuordnen der über das gesamte Photonenenergiespektrum verteilten charakteristischen Photonenenergien zu entsprechenden jeweils eindeutig zu einer Photonenenergie abgespeicherten Elementen und/oder Isotopen.Determining the elements and / or isotopes of the measurement object by assigning the characteristic photon energies distributed over the entire photon energy spectrum to corresponding elements and / or isotopes that are clearly stored in each case to form a photon energy.
Es hat sich überraschend herausgestellt, dass bei einem durch Anregung mit niederenergetischen Neutronen (2,45 MeV) gewonnenen Photonenenergiespektrum jedem Isotop eineindeutig mindestens eine charakteristische Photonenenergie zugeordnet werden kann, wenn das gesamte Photonenenergiespektrum mindestens bis zum Bereich von 12 MeV betrachtet wird. Nach einer Erfassung sämtlicher vorhandener Isotope und deren entsprechenden Photonenenergien ist es daher möglich, aus einem aufgenommenen Photonenenergiespektrum die in einem Messobjekt vorhandenen Elemente und Isotope durch Auswerten der charakteristischen Photonenenergien zu bestimmen. Die mit dem erfindungsgemäßen Verfahren bis 12 MeV ermittelten Photonenenergiespektren sind deshalb vollständig, weil Spektren, die jenseits dieser Größenordnung entstehen, nicht mehr auf die Neutronenbestrahlung zurückgeführt werden können. Grund hierfür sind die Bindungsenergien in den Atomkernen.It has surprisingly turned out that in the case of a photon energy spectrum obtained by excitation with low-energy neutrons (2.45 MeV), at least one characteristic photon energy can be unambiguously assigned to each isotope if the entire photon energy spectrum is considered at least up to the range of 12 MeV. After all the existing isotopes and their corresponding photon energies have been recorded, it is therefore possible to determine the elements and isotopes present in a measurement object from a recorded photon energy spectrum by evaluating the characteristic photon energies. The photon energy spectra determined with the method according to the invention up to 12 MeV are therefore complete because spectra which arise beyond this order of magnitude can no longer be traced back to the neutron radiation. The reason for this is the binding energies in the atomic nuclei.
Die Anregung niederenergetische Neutronen wird durch targetfreie Fusion von konzentrisch beschleunigten Deuterium-Ionen gewährleistet. Damit wird sichergestellt, dass praktisch keine Kernreaktion mit Bildung neuer Ra- dionuklide oder Isomere wie bei den oben beschriebenen prompten Neutronen-Aktivierungsanalyseverfahren erfolgt. Die resultierenden Photonenener- giespektren sind damit nicht miteinander vergleichbar. Bei dem durch Anregung mit niederenergetischen Neutronen gewonnenen Photonenenergiespektrum hat sich gezeigt, dass für jedes Isotop charakteristische Energielinien über das gesamte Photonenenergiespektrum verteilt sind. Im Unterschied zum Stand der Technik, bei dem lediglich ein Ausschnitt eines Photonenenergiespektrums nach charakteristischen Energielinien durchsucht wird, erfolgt bei dem erfindungsgemäßen Verfahren eine Analyse des gesamten Photonenenergiespektrums. Hierbei werden alle charakteristischen Energielinien eines Isotops berücksichtigt, da diese über das gesamte Photonenenergiespektrum verteilt sind. Auf diese Weise ist eine eineindeutige Analyse möglich. Zudem erfolgt praktisch keine Anregung und Umwandlung der untersuchten Isotope aufgrund der Bestrahlung.The excitation of low-energy neutrons is guaranteed by the target-free fusion of concentrically accelerated deuterium ions. This ensures that there is practically no nuclear reaction with the formation of new dionuclides or isomers as in the prompt neutron activation analysis methods described above. The resulting photon energy spectra are therefore not comparable. In the photon energy spectrum obtained by excitation with low-energy neutrons, it has been shown that characteristic energy lines are distributed over the entire photon energy spectrum for each isotope. In contrast to the prior art, in which only a section of a photon energy spectrum is searched for characteristic energy lines, the entire photon energy spectrum is analyzed in the method according to the invention. All characteristic energy lines of an isotope are taken into account here, since they are distributed over the entire photon energy spectrum. In this way, a clear analysis is possible. In addition, there is practically no excitation and conversion of the investigated isotopes due to the radiation.
Das Verfahren hat den Vorteil, dass alle in der Natur vorkommenden Isotope nachweisbar sind. Zudem muss das Messobjekt lediglich bestrahlt werden, ohne dass eine vorherige Probenpräparation notwendig ist. Die Probengeometrie und der Aggregatzustand des Messobjektes sind zudem beliebig.The method has the advantage that all isotopes occurring in nature can be detected. In addition, the measurement object only has to be irradiated without the need for prior sample preparation. The sample geometry and the physical state of the measurement object are also arbitrary.
Durch das Aufnehmen eines vollständigen Photonenenergiespektrums mittels Vielkanalmessung werden zudem alle Isotope gleichzeitig gemessen, so dass eine umfassende chemische Analyse sehr schnell erfolgen kann. Aufgrund des quantenphysikalischen Zusammenhangs der Photonenenergie E zur Lichtfre-quenz f (E = h x f mit h = Planksches Wirkungsquantum) entspricht das Photonenenergiespektrum einem aufgenommenen Lichtfrequenzspektrum. Weiterhin kann vorzugsweise ein quantitatives Bestimmen der chemischen Zusammensetzung des Messobjektes durch Messen des vollständigen messbaren Bereichs des Gamma-Photonenenergiespektrums und Ermitteln der Anteile der bestimmten Elemente und/oder Isotope durch Beziehen der Gamma-Photonenstrahlungsmenge pro Element und/oder Isotop auf die gesamte für alle ermittelten charakteristischen Photonenenergien ermittelte Gamma-Photonenstrahlungsmenge erfolgen.By recording a complete photon energy spectrum using multichannel measurement, all isotopes are also measured simultaneously, so that a comprehensive chemical analysis can be carried out very quickly. Due to the quantum-physical relationship of the photon energy E to the light frequency f (E = hxf with h = Plank's quantum of action), the photon energy spectrum corresponds to a recorded light frequency spectrum. Furthermore, a quantitative determination of the chemical composition of the measurement object can preferably be carried out by measuring the complete measurable range of the gamma-photon energy spectrum and determining the proportions of the specific elements and / or isotopes by relating the amount of gamma-photon radiation per element and / or isotope to the total for all characteristic gamma-photon radiation amount determined.
Die Anzahl der Photonenquanten der einzelnen charakteristischen Photonenenergien, die als Impulsspitzen aus der Kurve des aufgenommenen Photonenenergiespektrums herausragen, werden somit normiert, und es kann auf einfache Weise die prozentuale Verteilung der ermittelten Elemente bzw. Isotope an der gesamten Masse des Messobjektes berechnet werden.The number of photon quanta of the individual characteristic photon energies, which protrude as pulse peaks from the curve of the recorded photon energy spectrum, are thus standardized, and the percentage distribution of the elements or isotopes determined over the entire mass of the measurement object can be calculated in a simple manner.
Die Photonenstrahlungsmengen werden vorzugsweise beispielsweise mit bekannten Methoden zur Messkurvenverarbeitung durch Ermitteln der Flächen der charakteristischen Impulskurven des Photonenenergiespektrums an den Bereichen der charakteristischen Photonenenergien bestimmt. Es werden somit die über die Basiskurve des Photonenenergiespektrums hinausragenden Impulsspitzen erkannt und die Flächen unter diesen Impulsspitzen berechnet.The amounts of photon radiation are preferably determined, for example, using known methods for processing measurement curves by determining the areas of the characteristic pulse curves of the photon energy spectrum at the regions of the characteristic photon energies. The pulse peaks projecting beyond the base curve of the photon energy spectrum are thus recognized and the areas under these pulse peaks are calculated.
Zur Neutralisierung der Einflüsse der Messumgebung wird vorzugsweise ein Basis-Photonenenergiespektrum des Messraumes ohne das Messobjekt aufgenommen und ein zur Auswertung genutztes Photonenenergiespektrum aus der Differenz zwischen dem zur Analyse aufgenommenen Photonenenergiespektrum und dem Basis-Photonenenergiespektrum berechnet. Besonders vorteilhaft ist es, Ausschnitte des Messobjektes aus mehreren Richtungen zu bestrahlen und die mehreren Messergebnisse zu ortsabhängigen Analyse des Messobjektes auszuwerten. Das Messobjekt wird auf diese Weise vergleichbar mit einem Tomographie-Gerät abgescannt und liefert eine dreidimensionale Ortsauflösung der Isotopen- bzw. Elementenkonzentration.To neutralize the influences of the measurement environment, a base photon energy spectrum of the measurement space is preferably recorded without the measurement object, and a photon energy spectrum used for evaluation is calculated from the difference between the photon energy spectrum recorded for analysis and the base photon energy spectrum. It is particularly advantageous to irradiate sections of the measurement object from several directions and to evaluate the multiple measurement results for a location-dependent analysis of the measurement object. In this way, the measurement object is scanned comparable to a tomography device and provides a three-dimensional spatial resolution of the isotope or element concentration.
Aufgrund der kurzen Bestrahlungszeiten und der geringen erforderlichen Energie der thermischen Neutronen von E < 25 meV werden die Messobjekte nicht schädlich beeinflusst, so dass das Verfahren beispielsweise auch zur Untersuchung lebender Objekte eingesetzt werden kann.Due to the short irradiation times and the low required energy of the thermal neutrons of E <25 meV, the measuring objects are not adversely affected, so that the method can also be used for examining living objects, for example.
Die Aufgabe wird ferner durch die gattungsgemäße Einrichtung gelöst, indem die Neutronenquelle ein neben dem Messobjekt angeordneter Neutronengenerator ist. An dem mindestens einen Photonendetektor ist eine Auswerterecheneinheit gekoppelt, die zur Ermittlung von charakteristischen Photonenenergien aus den über eine Grundphotonenstrahlung hinausgehenden Gamma-Photonenstrahlungsmengen des Photonenenergiespektrums und zum Bestimmen der Elemente und/oder Isotope des Messobjektes durch Zuordnen der charakteristischen Photonenenergien zur entsprechenden jeweils eindeutig zu einer Photonenenergie abgespeicherten Elementen und/oder Isotopen ausgebildet ist.The object is further achieved by the generic device in that the neutron source is a neutron generator arranged next to the measurement object. An evaluation computing unit is coupled to the at least one photon detector, which unit is used to determine characteristic photon energies from the gamma-photon radiation amounts of the photon energy spectrum going beyond a basic photon radiation and to determine the elements and / or isotopes of the measurement object by assigning the characteristic photon energies to the corresponding photon energy stored elements and / or isotopes is formed.
Im Unterschied zu den bekannten Einrichtungen wird somit kein Forschungsreaktor sondern ein kompakter, vorzugsweise mobiler, Neutronengenerator eingesetzt. Die chemische Analyse kann auf diese Weise erstmalig in Messlabors und im direkten Produktionsbetrieb eingesetzt werden. Beispielsweise kann die Qualität und Zusammensetzung von Massengütern auf einem Förderband mit Hilfe der Einrichtung kontinuierlich überwacht werden, wobei die Massengutströme qualitätsabhängig umgelenkt werden können.In contrast to the known devices, therefore, no research reactor is used, but rather a compact, preferably mobile, neutron generator. In this way, chemical analysis can be used for the first time in measuring laboratories and in direct production. For example, the quality and composition of bulk goods on a conveyor belt can be continuously monitored using the device the bulk flows can be redirected depending on quality.
Weiter ist es vorteilhaft, wenn der mindestens eine Photonendetektor mit Mitteln zur Absorption von Neutronen geschirmt ist. Auf diese Weise kann der Streueinfluss von Photonen, die nicht von dem Messobjekt emittiert werden, reduziert und der Photonendetektor möglichst genau auf das Messobjekt ausgerichtet werden.It is also advantageous if the at least one photon detector is shielded with means for absorbing neutrons. In this way, the scattering influence of photons that are not emitted by the measurement object can be reduced and the photon detector can be aligned as precisely as possible with the measurement object.
Weiterhin ist vorzugsweise ein Fokussierelement zwischen dem Neutronengenerator und dem Messobjekt vorgesehen, dass zur thermischen Anpassung der Neutronen ausgebildet ist. Auf diese Weise wird die Neutronengeschwindigkeit beispielsweise an die Brownsche Bewegung der Luft ange- passt, so dass im Neutronenstrahl nahezu ausschließlich thermische Neutronen vorhanden sind.Furthermore, a focusing element is preferably provided between the neutron generator and the measurement object, which is designed for thermal adaptation of the neutrons. In this way, the neutron velocity is adapted, for example, to the Brownian movement of the air, so that thermal neutrons are almost exclusively present in the neutron beam.
Das Fokussierelement kann beispielsweise als neutronenabsorbierende Platte mit einer Durchlassbohrung ausgebildet sein.The focusing element can be designed, for example, as a neutron-absorbing plate with a passage bore.
Ein geeignetes Material für die Schirmung des Neutronendetektors und das Fokussierelement sind alle Materialien mit einem hohen Neutronenein- fangquerschnitt. A suitable material for the shielding of the neutron detector and the focusing element are all materials with a high neutron entrance cross section.
Die Erfindung wird nachfolgend anhand der beigefügten Zeichnungen näher erläutert. Es zeigen:The invention is explained below with reference to the accompanying drawings. Show it:
Fig. 1 - ein Prinzip-Blockdiagramm des erfindungsgemäßen Verfahrens zur zerstörungsfreien chemischen Analyse;1 shows a basic block diagram of the method according to the invention for non-destructive chemical analysis;
Fig. 2 - eine schematische Darstellung des Eintauchens eines Neutrons in einen Atomkern und des Aussendens von Gamma- Photonenenergie;Fig. 2 is a schematic representation of the immersion of a neutron in an atomic nucleus and the emission of gamma-photon energy;
Fig. 3 - einen Ausschnitt eines aufgenommenen Gamma-3 - a section of a recorded gamma
Photonenenergiespektrums;Photon energy spectrum;
Fig. 4 - ein Blockdiagramm einer erfindungsgemäßen Einrichtung zur zerstörungsfreien chemischen Analyse.Fig. 4 - a block diagram of a device according to the invention for non-destructive chemical analysis.
Die Figur 1 lässt ein schematisches Blockdiagramm des erfindungsgemäßen Verfahrens zur zerstörungsfreien chemischen Analyse von Messobjekten 1 erkennen. Das Messobjekt 1 wird kurzzeitig oder kontinuierlich mit Hilfe einer in der Nähe des Messobjektes 1 angeordneten Neutronenquelle 2 mit Neutronen n bestrahlt, die jeweils in die Atomkerne eintauchen. Hierbei wird Gamma-Photonenenergie Eγ ausgesendet. Ein Teil der ausgesendeten Gamma-Photonenquanten wird mit einem Gamma-Photonendetektor 3 gemessen und über eine an sich bekannte Messelektronik 4 an eine Auswerterecheneinheit 5 geleitet.FIG. 1 shows a schematic block diagram of the method according to the invention for the non-destructive chemical analysis of measurement objects 1. The measurement object 1 is briefly or continuously irradiated with neutrons n, which are arranged in the vicinity of the measurement object 1, and which each immerse into the atomic nuclei. Here gamma-photon energy Eγ is emitted. A part of the emitted gamma photon quanta is measured with a gamma photon detector 3 and sent to an evaluation computing unit 5 via measuring electronics 4 known per se.
Dort wird zunächst im Schritt einer Datenaufnahme D ein Photonenenergiespektrum 6 aufgenommen, indem die Anzahl N von Photonenquanten über die jeweilige Photonenenergie Eγ aufgetragen wird. In einem Schritt der Auswertung A werden charakteristische Photonenenergien Eγ als über eine Grundphotonenstrahlung hinausgehende Gamma-Photonenstrahlungsmenge des Photonenenergiespektrums 6 ermittelt, indem die Impulsspitzen beispielsweise mittels bekannter Signalkurvenaus- wertemethoden detektiert werden. Aus den charakteristischen Photonenenergien Eγ wird dann durch Zuordnung zu den entsprechenden jeweils eindeutig zu einer Photonenenergie abgespeicherten bekannten Elementen und/oder Isotopen die in dem Messobjekt 1 vorhandenen Elemente und/oder Isotope bestimmt.A photon energy spectrum 6 is first recorded there in the step of data acquisition D by plotting the number N of photon quanta over the respective photon energy E γ . In a step of the evaluation A, characteristic photon energies E γ are determined as the amount of gamma-photon radiation in the photon energy spectrum 6 going beyond a basic photon radiation, by detecting the pulse peaks, for example, by means of known signal curve evaluation methods. The elements and / or isotopes present in the measurement object 1 are then determined from the characteristic photon energies E γ by assignment to the corresponding known elements and / or isotopes that are clearly stored in each case to a photon energy.
Es ist weiterhin erkennbar, dass die Flächen unterhalb der charakteristischen Impulskurven des Photonenenergiespektrums an den Bereichen der charakteristischen Photonenenergien Eγ ermittelt werden. Durch Normierung der Flächen können dann die Anteile der Elemente an der Gesamtmasse des Messobjekts 1 sehr genau bestimmt werden, da das aufgenommene Photonenenergiespektrum 6 sämtliche bekannten Elemente und/oder Isotope berücksichtigt.It can also be seen that the areas below the characteristic pulse curves of the photon energy spectrum are determined at the regions of the characteristic photon energies E γ . By normalizing the areas, the proportions of the elements in the total mass of the measurement object 1 can then be determined very precisely, since the recorded photon energy spectrum 6 takes into account all known elements and / or isotopes.
Damit kann mit einer einzigen Messung eine vollständige chemische Analyse des Messobjektes 1 vorgenommen werden, ohne dass das Messobjekt 1 präpariert werden muss oder einer Untersuchung ein auf das Vorhandensein einzelner Elemente bzw. Isotope erforderlich ist.A complete chemical analysis of the measurement object 1 can thus be carried out with a single measurement, without the measurement object 1 having to be prepared or an examination being necessary for the presence of individual elements or isotopes.
Die Figur 2 lässt das dem Verfahren zugrundeliegende physikalische Grundprinzip in schematischer Darstellung erkennen. Beim Eintauchen eines Neutrons n in einen Atomkern AX wird der Atomkern A+1χ" stark angeregt. Hieraus resultiert eine sofortige Umordnung der Nukleonen in einen neuen, energetisch günstigsten Zustand A+1X, wobei die überschüssige Energie durch prompte Emission elektromagnetischer Strahlung in Form charakteristischer Gamma-Photonenquanten mit einer Gamma-Photonenenergie Eγ abgegeben wird. Die Gamma-Photonenenergie Eγ ist die Differenz aus der Bindungsenergie EB und der Rückwandlungsenergie ER zum Annehmen des neuen Zustande des Atomkerns.FIG. 2 shows the basic physical principle on which the method is based in a schematic representation. When a neutron n is immersed in an atomic nucleus A X, the atomic nucleus A + 1 χ "is strongly stimulated. This results in an immediate rearrangement of the nucleons into a new, energetically most favorable state A + 1 X, with the excess energy is emitted by prompt emission of electromagnetic radiation in the form of characteristic gamma photon quanta with a gamma photon energy E γ . The gamma photon energy E γ is the difference between the binding energy E B and the reconversion energy E R for assuming the new state of the atomic nucleus.
Der dargestellte prompte Vorgang dauert längstens 10"17 Sekunden vom Eintauchen des Neutrons in den Atomkern an.The prompt process shown lasts at most 10 "17 seconds from the immersion of the neutron in the atomic nucleus.
Die Figur 3 lässt ein mit dem Verfahren aufgenommenes beispielhaftes Gamma-Photonenenergiespektrum mit charakteristischen Impulskurven bei charakteristischen Photonenenergien von 380,99 keV, 393,65 keV, 41 1 ,80 keV, 418,59 keV, 440,08 keV und 444, 15 keV erkennen. Aus den unterhalb dieser charakteristischen Impulskurven liegenden Flächen wird die Photonenanzahl N bestimmt.FIG. 3 shows an exemplary gamma photon energy spectrum recorded with the method with characteristic pulse curves at characteristic photon energies of 380.99 keV, 393.65 keV, 41 1, 80 keV, 418.59 keV, 440.08 keV and 444, 15 keV detect. The number of photons N is determined from the areas below these characteristic pulse curves.
Unter der Annahme, dass das Photonenenergiespektrum vollständig ist, kann zudem durch Normieren der einzelnen Photonenmengen pro charakteristischer Photonenenergie Eγ ein Anteil des zugehörigen Elements an der Gesamtmasse des Messobjektes 1 berechnet werden, da die Impulshöhen sämtliche vorhandenen Elemente bzw. Isotope des Messobjektes 1 wiedergeben und die Summe der ermittelten Flächen der charakteristischen Impulskurven die vollständige Masse (100 %) des Messobjektes 1 ausmachen. Unterhalb des Diagramms ist die zu dem Photonenenergiespektrum gehörige Standardabweichung aufgetragen.Assuming that the photon energy spectrum is complete, by normalizing the individual photon quantities per characteristic photon energy E γ, a proportion of the associated element in the total mass of the measurement object 1 can be calculated, since the pulse heights reflect all the elements or isotopes of the measurement object 1 and the sum of the determined areas of the characteristic pulse curves make up the complete mass (100%) of the measurement object 1. The standard deviation belonging to the photon energy spectrum is plotted below the diagram.
Die Figur 4 lässt ein Blockdiagramm einer erfindungsgemäßen Einrichtung zur zerstörungsfreien chemischen Analyse eines Messobjektes 1 erkennen. In der Nähe des Messobjektes 1 ist ein vorzugsweise tragbarer Neutronen- generator 2 angeordnet, dessen Neutronenstrahl n auf das Messobjekt 1 gerichtet ist. Zwischen dem Neutronengenerator 2 und dem Messobjekt 1 befindet sich ein Neutronenmoderator 7, zur Anpassung der Neutronengeschwindigkeit, um thermische Neutronen n zu erzeugen, die an die Brown- sche Bewegung der Luft angepasst sind, und ein Fokussiermittel 8, um den Neutronenstrahl n zu fokussieren:FIG. 4 shows a block diagram of a device according to the invention for non-destructive chemical analysis of a measurement object 1. In the vicinity of the measurement object 1 there is a preferably portable neutron arranged generator 2, the neutron beam n is directed to the measurement object 1. Between the neutron generator 2 and the measurement object 1 there is a neutron moderator 7 for adapting the neutron speed to generate thermal neutrons n, which are adapted to the Brownian movement of the air, and a focusing means 8 for focusing the neutron beam n:
Angrenzend an das Messobjekt 1 ist ein Gamma-Photonendetektor 3 angeordnet, der auf das Messobjekt 1 ausgerichtet und zur Aufnahme eines Photonenenergiespektrums ausgebildet ist. Mit Hilfe einer Vielkanalmessung wird somit die Anzahl der Photonenquanten in Abhängigkeit von der jeweiligen Photonenenergie Eγ bzw. der Lichtfrequenz v der Photonen gemessen und einer Auswerterecheneinheit 5 zugeführt. Der mindestens eine Photonendetektor 3 ist seitlich mit einer Abschirmung 9 versehen, um Störstrahlungseinflüsse zu reduzieren.Adjacent to the measurement object 1 is a gamma photon detector 3, which is aligned with the measurement object 1 and is designed to record a photon energy spectrum. With the aid of a multi-channel measurement, the number of photon quanta as a function of the respective photon energy E γ or the light frequency v of the photons is measured and fed to an evaluation computing unit 5. The at least one photon detector 3 is laterally provided with a shield 9 in order to reduce the effects of interference radiation.
Als Material für den Neutronenmoderator 7, das Fokussiermittel 8 und die Abschrimung 9 eignen sich alle Materialien mit kleiner Ordnungszahl und kleinem Einfangquerschnitt, beispielsweise Polyethylen, das mit einem Katalysator versetzt ist. Das Fokussiermittel 7 ist beispielsweise als Platte mit einem Loch ausgebildet.Suitable materials for the neutron moderator 7, the focusing means 8 and the shielding 9 are all materials with a small atomic number and a small cross-section, for example polyethylene, which is mixed with a catalyst. The focusing means 7 is designed, for example, as a plate with a hole.
Die Auswerterecheneinheit 5 ist beispielsweise programmtechnisch zur Ermittlung der charakteristischen Photonenenergien Eγ aus den über eine Grundphotonenstrahlung hinausgehenden Photonenstrahlungsmengen des Photonenenergiespektrums mittels Signalanalyse ausgebildet. Die Auswerterecheneinheit 5 greift auf eine abgespeicherte Tabelle 10 zu, in der die charakteristischen Photonenenergien Eγ sämtlicher bekannter Isotope und damit auch der Elemente abgelegt sind. Durch Korrelation der ermittelten charakteristischen Photonenenergien Eγ mit den in der Tabelle 10 abgespeicherten Photonenenergien Eγ für die Isotope kann nun eindeutig aus dem Photonenenergiespektrum auf die chemische Zusammensetzung des Messobjektes 1 geschlossen werden. Durch Auswertung der ausgestrahlten Photonenmenge pro charakteristischer Photonenenergie Eγ kann zudem auch der Anteil der einzelnen Isotope an der betrachteten Gesamtmasse hochgenau bestimmt werden.The evaluation computing unit 5 is designed, for example, in terms of program technology to determine the characteristic photon energies E γ from the photon radiation quantities of the photon energy spectrum that go beyond a basic photon radiation by means of signal analysis. The evaluation computing unit 5 accesses a stored table 10 in which the characteristic photon energies E γ of all known isotopes and thus also of the elements are stored. By correlating the determined Characteristic photon energies E γ with the photon energies Eγ for the isotopes stored in Table 10 can now be clearly concluded from the photon energy spectrum on the chemical composition of the measurement object 1. By evaluating the amount of photons emitted per characteristic photon energy E γ , the proportion of the individual isotopes in the total mass under consideration can also be determined with high precision.
Besonders vorteilhaft ist es, wenn das Messobjekt 1 mit Hilfe einer dreidimensionalen Messung abgescannt wird, so dass ähnlich wie bei einem Tomographie verfahren eine Ortsanalyse durchgeführt werden kann.It is particularly advantageous if the measurement object 1 is scanned with the aid of a three-dimensional measurement, so that a location analysis can be carried out similarly to a tomography method.
Vorzugsweise kann die Erfindung überall dort eingesetzt werden, wo es um einen qualitativen und/oder quantitativen Isotopen- oder Elementnachweis von Proben beliebigen Aggregatzustands und beliebiger Geometrie geht. Dies ist insbesondere bei der Prospektion von Rohstoffen, der Materialanalytik, der Qualitätskontrolle und Qualitätssicherung, im investigativen u nd forensischen Bereich (Beweissicherung, Spurennachweis), beim Nachweis von Waffen und Sprengstoff an Flughäfen sowie bei der Reinstoffanalytik in der chemischen Industrie der Fall. The invention can preferably be used wherever a qualitative and / or quantitative isotope or element detection of samples of any physical state and any geometry is concerned. This is particularly the case for the prospection of raw materials, material analysis, quality control and quality assurance, in the investigative and forensic area (preservation of evidence, evidence of evidence), the detection of weapons and explosives at airports, as well as pure substance analysis in the chemical industry.

Claims

Ansprüche Expectations
1. Verfahren zur zerstörungsfreien chemischen Analyse von Messobjekten (1 ) durch Bestrahlen des Messobjektes (1 ) mit durch targetfreie Fusion von konzentrisch beschleunigten Deuterium-Ionen generierten Neutronen n und Messen der während der Bestrahlung von dem Messobjekt (1 ) prompt emittierten Gamma-Photonenstrahlungsmenge aus der Anzahl von Gamma-Photonenquanten und der jeweiligen Photonenenergie (Eγ) zum Aufnehmen eines Photonenenergiespektrums (6), gekennzeichnet durch1. A method for the non-destructive chemical analysis of measurement objects (1) by irradiating the measurement object (1) with neutrons generated by target-free fusion of concentrically accelerated deuterium ions and measuring the amount of gamma photon radiation promptly emitted by the measurement object (1) during the irradiation the number of gamma photon quanta and the respective photon energy (E γ ) for recording a photon energy spectrum (6), characterized by
Ermitteln von charakteristischen Photonenenergien (Ev) aus den über eine Untergrundphotonenstrahlung hinausgehenden Gamma-Photonenstrahlungsmengen des gesamten Photonenenergiespektrums (6) mindestens bis zum Bereich von 12 MeV undDetermination of characteristic photon energies (E v ) from the gamma-photon radiation quantities of the entire photon energy spectrum (6) going beyond background photon radiation at least up to the range of 12 MeV and
Bestimmen der Elemente und/oder Isotope des Messobjektes (1 ) durch Zuordnen der über das gesamte Photonenenergiespektrum (6) verteilten charakteristischen Photonenenergien (Eγ) zu entsprechenden jeweils eindeutig zu einer Photonenenergie (Eγ) abgespeicherten Elementen und/oder Isotopen.Determination of the elements and / or isotopes of the measurement object (1) by assigning the characteristic photon energies (E γ ) distributed over the entire photon energy spectrum (6) to corresponding elements and / or isotopes stored uniquely to form a photon energy (E γ ).
2. Verfahren nach Anspruch 1 , gekennzeichnet durch quantitatives Bestimmen der chemischen Elementzusammensetzung des Messobjektes (1 ) durch Messen des vollständigen messbaren Bereichs des Photonenenergiespektrums (6) und Ermitteln der Anteile der bestimmten Elemente und/oder Isotope durch Beziehen der Gamma- Photonenstrahlungsmenge pro Element und/oder Isotop auf die ge- samte für alle ermittelten charakteristischen Photonenenergien (Eγ) ermittelte Photonenstrahlungsmenge.2. The method according to claim 1, characterized by quantitative determination of the chemical element composition of the measurement object (1) by measuring the complete measurable range of the photon energy spectrum (6) and determining the proportions of the determined elements and / or isotopes by referring to the amount of gamma photon radiation per element and / or isotope on the total amount of photon radiation determined for all determined characteristic photon energies (E γ ).
3. Verfahren nach Anspruch 1 oder 2, gekennzeichnet durch Bestimmen der Gamma-Photonenstrahlungsmengen durch Ermitteln der Flächen der charakteristischen Impulskurven des Photonenenergiespektrums (6) an den Bereichen der charakteristischen Photonenenergien (Eγ).3. The method according to claim 1 or 2, characterized by determining the gamma photon radiation amounts by determining the areas of the characteristic pulse curves of the photon energy spectrum (6) at the areas of the characteristic photon energies (E γ ).
4. Verfahren nach einem der vorhergehenden Ansprüche, gekennzeichnet durch Aufnehmen eines Basis-Photonenenergiespektrums des Messraumes ohne das Messobjekt (1 ) und Berechnen eines zur Auswertung genutzten Photonenenergiespektrums (6) aus der Differenz zwischen dem zur Analyse aufgenommenen Photonenenergiespektrum (6) und dem Basis-Photonenenergiespektrum.4. The method according to any one of the preceding claims, characterized by recording a base photon energy spectrum of the measuring space without the measurement object (1) and calculating a photon energy spectrum (6) used for evaluation from the difference between the photon energy spectrum (6) recorded for analysis and the base photon energy spectrum.
5. Verfahren nach einem der vorhergehenden Ansprüche, gekennzeichnet durch Bestrahlen von Ausschnitten des Messobjektes (1 ) aus mehreren Richtungen und Auswerten der mehreren Messergebnisse zur ortsabhängigen Analyse des Messobjektes (1 ).5. The method according to any one of the preceding claims, characterized by irradiating sections of the measurement object (1) from a plurality of directions and evaluating the plurality of measurement results for the location-dependent analysis of the measurement object (1).
6. Einrichtung zur zerstörungsfreien chemischen Analyse von Messobjekten (1 ) mit einer Neutronenquelle (2) zum kurzzeitigen Bestrahlen des Messobjektes (1 ) mit Neutronen (n) und mit mindestens einem auf das Messobjekt (1 ) ausgerichteten Photonendetektor (3) zum Messen der prompt nach dem Bestrahlen von den Messobjekt (1 ) emittierten Gamma-Photonenstrahlungsmenge aus der Anzahl von Photonenquanten und der jeweiligen Photonenenergie (Eγ), dadurch gekennzeichnet, dass die Neutronenquelle (2) ein neben dem Messobjekt (1 ) angeordneter Neutronengenerator (2) ist und eine Auswerterecheneinheit (5) an den mindestens einen Photonendetektor (3) gekoppelt ist, wobei die Auswerterecheneinheit (5) zur Durchführung des Verfahrens nach einem der vorhergehenden Ansprüche ausgebildet ist.6.Device for non-destructive chemical analysis of measurement objects (1) with a neutron source (2) for briefly irradiating the measurement object (1) with neutrons (n) and with at least one photon detector (3) aligned with the measurement object (1) for measuring the prompt after irradiation of the quantity of gamma photon radiation emitted by the measurement object (1) from the number of photon quanta and the respective photon energy (E γ ), characterized in that the neutron source (2) is a neutron generator (2) arranged next to the measurement object (1) and a Evaluation computing unit (5) is coupled to the at least one photon detector (3), the evaluation computing unit (5) being designed to carry out the method according to one of the preceding claims.
7. Einrichtung nach Anspruch 6, dadurch gekennzeichnet, dass der Neutronengenerator (2) mobil ist.7. Device according to claim 6, characterized in that the neutron generator (2) is mobile.
8. Einrichtung nach Anspruch 6 oder 7, dadurch gekennzeichnet, dass der mindestens eine Photonendetektor (3) mit Mitteln zur Absorption von Neutronen (n) geschirmt ist.8. Device according to claim 6 or 7, characterized in that the at least one photon detector (3) with means for absorbing neutrons (n) is shielded.
9. Einrichtung nach einem der Ansprüche 6 bis 8, gekennzeichnet durch ein Fokussierelement zwischen dem Neutronengenerator (2) und dem Messobjekt (1 ), wobei das Fokussierelement zur thermischen Anpassung der Neutronen (n) ausgebildet ist.9. Device according to one of claims 6 to 8, characterized by a focusing element between the neutron generator (2) and the measurement object (1), wherein the focusing element is designed for thermal adaptation of the neutrons (n).
10. Computerprogramm mit Programmcodemitteln zur Durchführung des Verfahrens nach einem der vorhergehenden Ansprüche, wenn das Computerprogramm auf einem Computer ausgeführt wird.10. Computer program with program code means for performing the method according to one of the preceding claims, when the computer program is executed on a computer.
1 1. Computerprogramm nach Anspruch 10 mit einer Datenbank, dadurch gekennzeichnet, dass die Datenbank die charakteristischen Photonenenergien (Ey) der Elemente und/oder Isotope enthält.1 1. Computer program according to claim 10 with a database, characterized in that the database contains the characteristic photon energies (E y ) of the elements and / or isotopes.
12. Computerprogramm mit Programmcodemitteln gemäß Anspruch 10 oder 1 1 , die auf einem coumputerlesbaren Datenträger gespeichert sind. 12. Computer program with program code means according to claim 10 or 1 1, which are stored on a computer readable data carrier.
3. Datenbank mit einer Vielzahl von Einträgen charakteristischer Photo- nenenerigen (Ey) bezogen auf zugehörige Elemente und/oder Isotope zur Verwendung zur Durchführung des Verfahrens nach einem der vorhergehenden Ansprüche. 3. Database with a large number of entries of characteristic photo-genes (E y ) based on associated elements and / or isotopes for use in carrying out the method according to one of the preceding claims.
EP03729816A 2002-04-05 2003-04-02 Method and device for promptly conducting non-destructive chemical analysis of test objects Withdrawn EP1493045A2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10215070 2002-04-05
DE10215070A DE10215070A1 (en) 2002-04-05 2002-04-05 Method and device for prompt non-destructive chemical analysis of measurement objects
PCT/DE2003/001084 WO2003085418A2 (en) 2002-04-05 2003-04-02 Chemical analysis of test objects using neutrons that are generated by concentrically accelerated deuterium ions

Publications (1)

Publication Number Publication Date
EP1493045A2 true EP1493045A2 (en) 2005-01-05

Family

ID=28684774

Family Applications (1)

Application Number Title Priority Date Filing Date
EP03729816A Withdrawn EP1493045A2 (en) 2002-04-05 2003-04-02 Method and device for promptly conducting non-destructive chemical analysis of test objects

Country Status (5)

Country Link
US (1) US20050195932A1 (en)
EP (1) EP1493045A2 (en)
AU (1) AU2003240384A1 (en)
DE (1) DE10215070A1 (en)
WO (1) WO2003085418A2 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006033662A1 (en) 2006-07-20 2008-01-24 Forschungszentrum Dresden - Rossendorf E.V. Method for determining a material composition of a material sample
DE102006033661A1 (en) 2006-07-20 2008-01-24 Forschungszentrum Dresden - Rossendorf E.V. Detector arrangement for the angular resolution detection of radiation and method for operating the same
PL3410104T3 (en) * 2017-05-31 2021-12-06 Aachen Institute For Nuclear Training Gmbh Method and device for multi-element analysis based on neutron activation and use
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

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4397810A (en) * 1979-03-16 1983-08-09 Energy Profiles, Inc. Compressed beam directed particle nuclear energy generator
FR2652651B1 (en) * 1989-10-03 1991-12-13 Commissariat Energie Atomique SYSTEM FOR DETECTION OF SUBSTANCES AND IN PARTICULAR EXPLOSIVES, BY NEUTRONIC IRRADIATION THEREOF.
US5539788A (en) * 1992-10-08 1996-07-23 Westinghouse Electric Corporation Prompt gamma neutron activation analysis system
US5383538A (en) * 1993-10-04 1995-01-24 Eaton Corporation Brake squeal spring clip dampener
IL129609A0 (en) * 1996-11-01 2000-02-29 Miley George H Spherical inertial electrostatic confinement device as a tunable x-ray source
US5982838A (en) * 1997-03-26 1999-11-09 Western Kentucky University Method and portable apparatus for the detection of substances by use of neutron irradiation
DE19745669B4 (en) * 1997-10-17 2004-03-04 Bruker Daltonik Gmbh Analysis system for the non-destructive identification of the contents of objects, especially explosives and chemical warfare agents
JP2001523010A (en) * 1997-11-12 2001-11-20 ザ・ボード・オブ・トラスティーズ・オブ・ザ・ユニバーシティ・オブ・イリノイ Inertial electrostatic confinement (IEC) fusion device and method with gate valve pulsation
WO2001007888A2 (en) * 1999-07-23 2001-02-01 Westinghouse Electric Company Llc Pulsed gamma neutron activation analysis (pgnaa) method and apparatus for nondestructive assay of containerized contaminants

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO03085418A2 *

Also Published As

Publication number Publication date
US20050195932A1 (en) 2005-09-08
AU2003240384A1 (en) 2003-10-20
AU2003240384A8 (en) 2003-10-20
DE10215070A1 (en) 2003-10-30
WO2003085418A3 (en) 2003-12-18
WO2003085418A2 (en) 2003-10-16

Similar Documents

Publication Publication Date Title
DE68915071T2 (en) Method and system for the detection of nitrogenous explosives by means of nuclear magnetic resonance absorption.
DE19745669B4 (en) Analysis system for the non-destructive identification of the contents of objects, especially explosives and chemical warfare agents
DE2648434A1 (en) METHODS OF ANALYZING COAL OR COOK
DE1923983A1 (en) Method and device for the non-destructive investigation of a quantity of nuclear fuel
DE102005056385A1 (en) Method and device for the safety detection of liquids with a radiation source
WO2018219406A1 (en) Method and device for multielement analysis on the basis of neutron activation, and use
DE2341758A1 (en) ANALYSIS SYSTEM
DE3047824C2 (en) Method and device for the quantitative determination of the concentration of the mineral material in coal that forms the ash content
EP3410104B1 (en) Method and device for multi-element analysis based on neutron activation and use
DE102010031844A1 (en) Method for non-destructive elemental analysis of large volume samples and apparatus for carrying out the same
DE60219219T2 (en) METHOD AND DEVICE FOR CARRYING OUT A QUALITY CONTROL ON A MOX FENCER
DE69812935T2 (en) METHOD AND DEVICE FOR MEASURING THE RELATIVE PART OF URAN AND PLUTONIUM IN A BODY
DE2727989A1 (en) DEVICE FOR DETERMINATION OF URANIUM AND / OR THORIUM IN ORIENTAL SAMPLE
DE1912982A1 (en) Device for the nondestructive and separate determination of the concentrations of fissile substances in a test body
DE3439845A1 (en) METHOD FOR DETERMINING THE EXPOSURE OF A BODY TO NEUTRON
EP1493045A2 (en) Method and device for promptly conducting non-destructive chemical analysis of test objects
DE4017100A1 (en) Fuel rod content inspection unit - has gamma radiation for excitation of low gamma emitting materials
DE102009057276A1 (en) Method for the identification of explosives by neutron bombardment
DE2001513A1 (en) Device for measuring the content of an element in a sample by gamma absorptiometry
DE2046606A1 (en) X-ray fluorescence analysis - using germanium (lithium) detector for non dispersive k-fluorescence analysis
EP1131653B1 (en) Method and device for measuring the radioactive contamination of a test object
DE1648901C (en) Method and device for the determination of fissile material in samples, e.g. B. in nuclear fuel elements
DE2613700A1 (en) Detector for fissionable material long objects esp. fuel rods - includes layer which selectively attenuates source neutrons
DE1648901B1 (en) PROCESS AND DEVICE FOR DETERMINING FISSIBLE MATERIAL IN SAMPLES, E.G. IN NUCLEAR FUEL ELEMENTS
DE2915879C2 (en) Method for the simultaneous quantitative determination of nitrogen, phosphorus and potassium in plants and fertilizers

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20040915

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL LT LV MK

17Q First examination report despatched

Effective date: 20041216

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20060419