CN107884809B - Neutron detector and neutron detection method - Google Patents
Neutron detector and neutron detection method Download PDFInfo
- Publication number
- CN107884809B CN107884809B CN201711106734.8A CN201711106734A CN107884809B CN 107884809 B CN107884809 B CN 107884809B CN 201711106734 A CN201711106734 A CN 201711106734A CN 107884809 B CN107884809 B CN 107884809B
- Authority
- CN
- China
- Prior art keywords
- neutron
- layer
- support substrate
- capture layer
- cathode
- 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.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T3/00—Measuring neutron radiation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T3/00—Measuring neutron radiation
- G01T3/08—Measuring neutron radiation with semiconductor detectors
Abstract
The present disclosure relates to a neutron detection technology, and discloses a neutron detector and a neutron detection method, wherein the neutron detector comprises: a neutron detection cathode; and a vacuum vessel housing a neutron detection cathode and an anode or an array of anodes; the neutron detection cathode comprises a thermal neutron capture material, can convert incident thermal neutrons to generate electrons capable of being directly detected, and comprises: the device comprises a support substrate, an electrode layer and a neutron trapping layer, wherein the electrode layer is positioned between the support substrate and the neutron trapping layer; the neutron capture layer comprises a neutron capture material, and electrons are released after the neutron capture material captures neutrons; the support substrate is made of a neutron transmission material, neutrons enter the neutron capture layer from the direction from the neutron capture layer to the support substrate, and electrons generated by the neutron capture layer are released from the support substrate to the neutron capture layer; therefore, electrons converted by the capture layer from neutrons can be accurately multiplied or directly detected, and sensitive detection of thermal neutrons is further realized.
Description
Technical Field
The present invention relates generally to neutron detection technology, and more particularly, to a neutron detection cathode capable of converting thermal neutrons into electrons, a detector having a multiplication detection function on the converted electrons, and a neutron detection method.
Background
Unlike high-energy charged particles and high-energy photons, neutrons do not interact electromagnetically with the detector medium, ionize or excite the medium atoms in the presence of coulomb interactions as a medium; the neutron cannot generate photoelectric effect, compton scattering and the like with the medium, so that the neutron is not easy to be directly detected, and the neutron is generally detected through nuclear scattering or nuclear reaction with atomic nuclei of the detector medium.
The neutrons are classified according to their energy levels as follows: neutrons with kinetic energy less than 0.002eV, namely equivalent temperature below about 20K are cold neutrons; neutrons with kinetic energy ranging from 0.002 to 0.5eV are classified as thermal neutrons; neutrons with kinetic energy of 1 eV-1 keV are epithermal neutrons or slow neutrons; the kinetic energy of the fast neutrons is greater than 1 keV; neutrons with kinetic energy greater than 10MeV are relativistic neutrons, where the speed of the neutrons approaches the speed of light and relativistic effects begin to manifest.
The common thermal neutron detector is generally an imaging detector with high position precision, has small effective detection area and high price, and is not beneficial to monitoring a large-area background field with neutron radiation.
The above information disclosed in this background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not constitute prior art that is already known to a person of ordinary skill in the art.
Disclosure of Invention
In this summary, concepts in a simplified form are introduced that are further described in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
It is a primary object of the present invention to overcome at least one of the above-mentioned drawbacks of the prior art, and to provide a neutron detection cathode, a neutron detector and a neutron detection method capable of performing multiplicative detection on neutrons, which can perform accurate multiplicative detection or direct detection on electrons converted from the neutron through the capture layer, thereby realizing sensitive detection on thermal neutrons.
It is another primary object of the present invention to overcome at least one of the above-mentioned drawbacks of the prior art and to provide a neutron detection cathode, a neutron detector and a method of neutron detection with extremely high sensitivity and extremely low noise.
In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:
according to one aspect of the present invention, there is provided a neutron detection cathode comprising a thermal neutron capture material capable of being converted to produce directly detectable electrons upon incidence of thermal neutrons, the neutron detection cathode comprising: a support substrate, an electrode layer, and a neutron capture layer. The electrode layer is arranged on the support substrate; the neutron capture layer is arranged on the other side, opposite to the supporting substrate, of the electrode layer, the neutron capture layer comprises a neutron capture material, and electrons are released after the neutron capture material captures neutrons. The neutron multiplication detection device also comprises a vacuum container dynode and an anode; the vacuum container is provided with an entrance window; the electrode layer covers the inner surface of the vacuum container entrance window; the neutron capture layer covers the inner surface of the electrode layer; thereby, the neutron can be accurately detected in a multiplication mode.
According to an embodiment of the invention, the neutron capture layer is a coating of a compound containing gadolinium or a gadolinium-doped resistive coating.
According to an embodiment of the present invention, the material of the supporting substrate is a neutron-transmitting material; neutrons are incident on the neutron capture layer from the support substrate side, and electrons generated by the neutron capture layer are released to the opposite side of the support substrate.
According to an embodiment of the present invention, the material of the supporting substrate is a neutron transmitting material or a neutron shielding material; neutrons are incident on the neutron capture layer from the opposite side of the support substrate, and electrons generated by the neutron capture layer are released to the opposite side of the support substrate.
According to an embodiment of the present invention, the neutron capture layer has a sheet resistance of a semiconductor thin film, and the electrode layer supplies a voltage to the neutron capture layer to form an electric field, and collects the emitted electrons by the action of the electric field.
According to an embodiment of the present invention, the vacuum container is made of glass; or, the incidence window of the vacuum container is made of a conductive material, the electrode layer and the incidence window of the vacuum container are integrated, and the neutron capture layer is directly formed on the inner surface of the incidence end of the vacuum container.
According to an embodiment of the invention, an electron beam focusing electric field device is arranged between the electrode layer and a first one of the dynodes.
According to another aspect of the present invention, there is provided a neutron detector comprising a container, a cathode layer, and an anode; the anode is a single anode or an anode array, collecting electrons emitted from the neutron detection cathode; the container houses the neutron detection cathode and the anode.
According to an embodiment of the present invention, the container has an entrance window, the cathode layer is formed on an inner surface of the entrance window, the neutron capture layer is formed on an inner surface of the cathode layer, and the neutron capture layer generates electrons after capturing neutrons; the electron multiplication detection structure is located in the vacuum container and detects the electrons through direct multiplication so as to indirectly detect neutrons.
According to one aspect of the present invention, there is provided a neutron multiplication detection method, comprising the steps of:
preparing a cathode layer, a neutron capture layer and an anode in a vacuum state; the cathode layer, a neutron capture layer and an anode are sequentially arranged;
thermal neutrons pass through the cathode layer and are captured by the neutron capture layer, and electrons are generated;
the electrons are collected and detected by the anode under the combined action of the cathode layer and the anode.
According to an embodiment of the present invention, there may be one or more electron multiplication structures between the anode and the cathode, and the potential of the electron multiplication structures is between the anode and the cathode.
According to another aspect of the present invention, there is provided a neutron detector comprising a neutron detection cathode, an electron multiplier section, an anode or an array of anodes as described above, and a container: the electron multiplier is configured to cascade multiply electrons emitted from the neutron detection cathode; the anode or the anode array collects secondary electrons emitted from the electron multiplier section; the container accommodates the neutron detection cathode, the electron multiplier section, and the anode.
According to the technical scheme, the neutron multiplication detection device and the neutron multiplication detection method have the advantages and positive effects that:
1. the area of the neutron capture layer of the neutron detection cathode of the embodiment of the invention can be unlimited, and the geometrical structure of the detector used specifically depends on the development of the vacuum technology;
2. it should be understood that photocathodes in various photomultipliers can be directly replaced by neutron capture layers provided by the embodiment of the invention, and other processes are not changed, so that the photomultipliers can be directly converted into neutron electron multipliers;
3 the performance of the detector is mainly determined by the collection multiplication efficiency of the photomultiplier and the collection component, and is determined by the development of the industrial technology, so that the detector has large expandable space;
4. the signal reading mode can realize the rapid discrimination of the existence of large-area thermal neutron signals if the single anode is adopted; in case of multi-anode readout, position resolution can be achieved.
Drawings
Various objects, features and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, when considered in conjunction with the accompanying drawings. The drawings are merely exemplary of the invention and are not necessarily drawn to scale. In the drawings, like reference characters designate the same or similar parts throughout the different views. Wherein:
FIG. 1 is a schematic cross-sectional view of a neutron detection cathode according to an exemplary embodiment.
FIG. 2 is a schematic cross-sectional view of another neutron detection cathode shown in accordance with an exemplary embodiment.
FIG. 3 is a schematic diagram illustrating a neutron multiplicative detection device in accordance with an exemplary embodiment.
FIG. 4 is a schematic diagram illustrating another neutron multiplication detection apparatus according to an exemplary embodiment.
Wherein the reference numerals are as follows:
1. a vacuum vessel; 2. a cathode layer; 3. a neutron capture layer; 4. a dynode; 5. an anode; 6. a microchannel plate; 7. a multi-anode array.
Detailed Description
Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted.
FIG. 1 is a schematic cross-sectional view of a neutron detection cathode according to an exemplary embodiment.
As illustrated in fig. 1, an embodiment of the present invention provides a neutron detection cathode, which is a transmissive neutron detection cathode that releases electrons in response to incidence of neutrons, and includes a support substrate 1, an electrode layer 2, and a neutron capture layer 3.
As shown in FIG. 1, the transmissive neutron detection cathode has incident neutrons n that transmit in an energy range suitable for use0 A support substrate 1, an electrode layer 2 provided on the support substrate 1, and a neutron capture layer 3 provided on the electrode layer 2.
The support substrate 1 has an incident surface 11 as a neutron incident surface of the transmissive neutron detection cathode, and a support surface 12 facing the incident surface 11. The neutron capture layer 3 has a base surface 31 facing the support surface 12 of the support substrate 1, and a release surface 32 facing the base surface 31 and functioning as a photoelectron emission surface of the transmissive neutron detection cathode. The first surface 21 of the electrode layer 2 is in direct contact with the support surface 12 of the support substrate 1, the second surface 22 of the electrode layer 2 is in direct contact with the base surface 31 of the neutron-capture layer 3, and the electrode layer 2 is located between the support substrate 1 and the neutron-capture layer 3.
In the transmissive neutron detection cathode, incident neutron n0Incident from the incident surface 11 side of the support substrate 1 in response to the incident neutron n0For releasing electrons e from the release surface 32 of the neutron capture layer 3-. In summary, the neutron capture layer 3 makes the neutrons n0Enters from the base surface 312 side opposite to the support substrate 1, and emits electrons e toward the release surface 32 opposite to the support substrate 1-And (4) discharging. The electrode layer 2 is used to provide an electric field effect to facilitate the electron e-And (4) conveying the mixture to the anode.
It should be understood that the transmissive neutron detection cathode described above may be used in a transmissive detector, i.e., the radiation source is located on opposite sides of the detection cathode opposite the anode.
FIG. 2, on the other hand, is another embodiment of a neutron detection cathode according to the present inventionCross-sectional view of the reflective neutron detection cathode of (1). As shown in FIG. 2, the reflection-type neutron detection cathode has a function of transmitting or blocking incident neutrons n of an appropriate wavelength0 A support substrate 1, an electrode layer 2 disposed on the support substrate 1, and a neutron capture layer 3 disposed on the electrode layer 2.
The support substrate 1 has a support surface 12. The neutron capture layer 3 has a base surface 31 facing the support surface 12 of the support substrate 1, and a release surface 32 facing the base surface 31 and serving as a neutron incidence surface and an electron emission surface of the reflection-type neutron detection cathode 1. The first surface 21 of the electrode layer 2 is in direct contact with the support surface 12 of the support substrate 1, the second surface 22 of the electrode layer 2 is in direct contact with the base surface 31 of the neutron-capture layer 3, and the electrode layer 2 is located between the support substrate 1 and the neutron-capture layer 3.
In the reflection type neutron detection cathode, incident neutron n0After traveling from the neutron capture layer 3 toward the support substrate 1 and arriving, it corresponds to the incident neutron n0Electrons e are emitted in a direction from the support substrate 1 toward the neutron capture layer 3-. In summary, the neutron capture layer 3 makes the neutrons n0Incident from the opposite side of the support substrate 1 and emitting electrons e to the opposite side of the support substrate 1-. The support substrate 1 is preferably formed of a material that blocks neutrons. Since the support substrate 1 functions as a reinforcing member for supporting the neutron capture layer 3, a metal material such as lead is preferably used as the material of the support substrate.
In any of the transmissive neutron detection cathode and the reflective neutron detection cathode described above, the electrode layer 2 and the neutron capture layer 3 may have the same configuration as described below.
In the embodiment of the present invention, regarding the material of the neutron capture layer, neutron capture based on a nuclear reaction method may be selected. The nuclear reaction method is based on the fact that after neutrons and atomic nuclei undergo nuclear reaction, charged particles and/or gamma rays with high energy are released, and incident neutrons can be detected by recording secondary particles. The material of the neutron capture layer can be selected as a commonly used nuclide3He、6Li、10B, and the like. The isotopes and energy are in the heatThe reaction cross section of neutrons below the energy sub-region is much higher than other known light nuclei, and thus these three light isotopes are effective converters for detecting low-energy neutrons. The nuclear reaction after neutron absorption is as follows:
·n+3He→3H+1H+0.764MeV
·n+6Li→4He+3H+4.79MeV
·n+10B→7Li*+4He→7Li+4He+0.48MeVγ+2.3MeV(93％)
→7Li+4He+2.8MeV(7％)
the neutrons react with the fissile material to undergo nuclear fission, splitting into two fission fragments, and releasing approximately 170MeV of energy. Nuclear fission is divided into two categories: non-threshold fission, nuclide for thermal neutron detection233U、235U、239Pu; nuclear fission, nuclide with threshold for fast neutron detection232Th、238U、237Np. The neutron capture layer of the embodiment of the invention can be made of materials233U、235U、239Pu or232Th、238U、237Np。
In an embodiment of the invention, the materials of the neutron-capture layer, such as some rare earth heavy metals (e.g. samarium, europium, Gadolinium and dysprosium) have a particularly large neutron-capture cross section, especially two natural isotopes of Gadolinium (Gadolinium) containing odd neutrons155Gd and157gd, having the largest thermal neutron reaction cross section among known nuclides,10b has a cross-section of 3.8 kbran, and155gd and157the thermal neutron capture cross sections of Gd are respectively 6.1 × 104barn and 2.55 × 105barn, the reaction cross section of Gd sharply drops in a fast neutron energy area, and then the Gd enters a resonance interference area, and the two isotopes of Gd are almost transparent to fast neutrons and are natural thermal neutron capture agents, and the natural abundances of the two Gd isotopes are very considerable, and the detailed table is shown in the following table:
in an embodiment of the present invention, the neutron capture layer is a coating layer of a compound containing gadolinium, or a gadolinium-doped resistive coating layer. The two isotopes of Gd described above undergo a nuclear reaction by the following reaction equation:
n+155Gd→156Gd*→156Gd+γ(8.5MeV)+e- IC(0.039～0.19MeV)+X
n+157Gd→158Gd*→158Gd+γ(7.9MeV)+e- IC(0.029～0.20MeV)+X
155gd and157gd generates an unstable excited state with a very short lifetime after absorption of neutrons156Gd and158gd, total excitation energy 8.53MeV and 7.94MeV, respectively. The two emit a series of gamma (gamma) rays in the process of gradually exciting to a ground state; there is a great chance that the extra energy is transferred to the inner shell electrons of the atoms when the last stage is de-excited, so that the electrons are separated from the orbit and are emitted out to form electrons (internal conversion electron). Since the natural abundance of the two Gd isotopes is considerable, a specific example is that neutron capture can be achieved at low cost using a coating of gadolinium-containing oxide to ultimately achieve very low-noise multiplicative detection of neutrons.
It will be appreciated by those skilled in the art that the gadolinium compounds described in the examples of the present invention may be selected from: gadolinium oxide (Gadolinium oxide), Gadolinium oxide (Gadolinium oxide) Hydrate, Gadolinium Hydroxide Hydrate (REO) Gadolinium (ii i) Hydrate, Gadolinium Oxalate Hydrate (REO) Gadolinium (ii) oxolate Hydrate, Ultra Dry Gadolinium Chloride (REO) Gadolinium (ii) Chloride, Ultra Dry, Gadolinium triflate (Gadolinium) triflate (III) triflate, Gadolinium nitrate, Gadolinium hexahydrate (III) Gadolinium Chloride, Gadolinium (III) hexahydrate gadoline Chloride, Gadolinium fluoride (III) fluoride, Gadolinium bromide (III) Gadolinium bromide, Gadolinium iodide (III) gaiodide, Gadolinium sulfate (III) Hydrate, Gadolinium sulfate (III) borate, Gadolinium sulfate (III) sulfate, Gadolinium (III) or a combination thereof.
Because the penetration ability of neutrons is strong and the thickness is related to the detection efficiency, the thickness of the neutron capture layer can be in the order of nanometers and micrometers. Nano-scale refers to structure sizes in the range of 1 to 100 nanometers, in accordance with common general knowledge in the art; the micron scale generally refers to within 100 microns.
The embodiment of the invention provides a neutron detection device, which can be considered as that a neutron capture layer and an electrode layer are combined to form a cathode of a detector, wherein the electrode layer is positioned on a neutron incidence side, and the neutron capture layer is positioned close to an electron multiplication detection structure, so that electrons generated after the neutron capture layer reacts with neutrons are emitted to the electron multiplication detection structure under the action of an electric field.
The neutron detection device structure provided by the embodiment of the invention can refer to various photomultiplier tubes (PMT) and can be a photomultiplier tube with a end window type (Head-on) or Side window type (Side-on) structure. The side window type photomultiplier receives incident light from the side of the glass housing, and the end window type photomultiplier receives incident light from the top of the glass housing. In general, a side window type photomultiplier is inexpensive and widely used in a spectrophotometer and a general photometric measurement. Most side window type photomultiplier tubes use an opaque cathode (reflective cathode) and a ring focus type electron multiplier structure, which gives them a high sensitivity at low operating voltages. An end-window (also called top-window) photomultiplier has a translucent cathode (transmissive cathode) deposited on the inner surface of its entrance window, giving it a better uniformity than the side-window. The end-window photomultiplier is further characterized by having a cathode ranging from tens of square millimeters to hundreds of square centimeters. The end-window photomultiplier tube also has a large-size hemispherical optical window photomultiplier tube for high-energy physical experiments, which can capture incident light at a wide angle. The embodiment of the invention can be modified on the basis of the configuration, so that neutrons can be detected according to various requirements or environments.
In the embodiment of the present invention, the form of the electron multiplication detection structure refers to the structure of the existing photomultiplier, and for example, the structure may be: ring focus type, box grid type, linear focus type, louver type, fine mesh type microchannel plate (MCP) type, metal channel type, and the like, and it is also possible to mix two types of the above structures. Mixed dynodes can exert their respective advantages.
A specific embodiment of the present invention is described below with reference to the accompanying drawings: FIG. 3 is a schematic diagram illustrating a neutron multiplicative detection device in accordance with an exemplary embodiment.
As shown in the drawings, a neutron multiplication detection device according to an embodiment of the present invention may mainly include a vacuum container 1, an electrode layer 2, a neutron capture layer 3, a dynode 4, and an anode 5. The vacuum vessel 1 has an entrance window portion which may be an end-on window or a side-on window with reference to a photomultiplier tube (PMT). An electrode layer 2 is optionally coated on the inner surface of the entrance window portion, and the electrode layer 2 may be made of metal or other conductive material by a film forming technique. The neutron capture layer 3 covers the inner surface of the electrode layer and can be formed by a film forming technology by using a material which can react to generate an electric signal after being irradiated by neutrons. The neutron capture layer 3 may here be formed by a film forming technique, optionally with a material containing gadolinium oxide.
As for the film forming technique, in the embodiment of the present invention, Physical Vapor Deposition (PVD) or Chemical Vapor Deposition (CVD) represented by vacuum evaporation, sputtering evaporation, ion plating, or the like may be selected; or the metal electrode can be selected by electroplating, chemical plating or anodic oxidation.
As shown, in the embodiment of the present invention, the anode 5 is located in the vacuum vessel 1, and the anode 5 may be located at the other side of the vacuum vessel 1 opposite to the electrode layer 2. And the dynode 4 can be a plurality of dynodes which are distributed at intervals between the electrode layer 2 and the anode 5. As shown in fig. 3, the electrode layer 2, the plurality of dynodes 4 and the anode 5 are sequentially arranged from the entrance window to the anode 5, wherein the potentials of the respective electrodes are gradually increased in the above order to form an action electric field, and electrons generated by the reaction of the neutron capture layer 3 are gradually guided to multiply and amplify.
Thus, neutrons are incident on the neutron capture layer 3 from the incident end, and are captured by the neutron capture layer 3Electrons are generated after the electrons are subjected to the action of each electrode in a vacuum state, are multiplied and amplified step by each dynode 4 and then are collected by the anode 5, and neutron signals can be detected according to the change signals of the anode 5. These electrons striking the dynode 4 enable the dynode 4 to release more electrons which are then focused on the next dynode 4. Thus, the amplification factor can reach 10 after more than ten times of multiplication8～1010. Finally, the amplified current signal is collected at the anode at high potential.
In this embodiment, the neutron capture layer 3 is formed of gadolinium-containing oxide, which is effective in detecting slow neutrons. It should be understood that a neutron moderating mechanism, such as one made of light water, heavy water, or graphite, may be added outside the incident window to moderate fast neutrons into slow neutrons for detection.
In one embodiment, the vacuum container 1 is made of glass; the incident end or the whole of the vacuum container 1 can also be made of conductive material, and the electrode layer 2 can be integrated with the incident end or the whole of the vacuum container 1, of course, the vacuum container made of conductive material is isolated from the internal electrodes, so that the neutron capture layer 3 is directly formed on the inner surface of the incident end of the vacuum container 1.
In one embodiment, an electron beam focusing electric field device may also be disposed between the electrode layer 2 and the first dynode 4.
In one embodiment, the electron multiplication detecting structure may be in the form of: ring focus type, box grid type, linear focus type, louver type, fine mesh type microchannel plate (MCP) type, metal channel type, and the like, and it is also possible to mix two types of the above structures. Mixed dynodes can exert their respective advantages.
Another embodiment of the present invention is described below with reference to the accompanying drawings as follows: FIG. 4 is a schematic diagram illustrating another neutron multiplication detection apparatus according to an exemplary embodiment.
As shown in the figure, a neutron multiplication detection device according to an embodiment of the present invention may mainly include a vacuum container 1, an electrode layer 2, a neutron capture layer 3, a microchannel plate 6, and a multi-anode array 7. The vacuum vessel 1 has an entrance window site, which may be a reference microchannel plate detector (MCP). An electrode layer 2 is optionally coated on the inner surface of the entrance window portion, and the electrode layer 2 may be made of metal or other conductive material by a film forming technique. The neutron capture layer 3 covers the inner surface of the electrode layer and can be formed by a film forming technology by using a material which can react to generate an electric signal after being irradiated by neutrons. The neutron capture layer 3 may here be formed by a film forming technique, optionally with a compound material containing gadolinium.
The microchannel plate 6 and the multi-anode array 7 are positioned in the vacuum container 1, and the multi-anode array 7 can be positioned on the other side of the vacuum container 1 opposite to the cathode. As shown in fig. 4, from the entrance window to the multi-anode array 7, the electrode layer 2, the microchannel plate 6 and the multi-anode array 7 are arranged in sequence so as to form an action electric field, and electrons generated by the reaction of the neutron capture layer 3 are guided in the multi-anode array 7 stage by stage to be multiplied.
Thus, neutrons enter the neutron capture layer 3 from the incident end, electrons are generated after the neutron capture layer 3 captures the neutrons, and the electrons are subjected to the action of each electrode in a vacuum state, multiplied and amplified step by the microchannel plate 6 and the multi-anode array 7 and then collected by the emergent anode.
It can be further understood that an embodiment of the present invention provides a neutron multiplication detection method, which mainly includes the steps of:
preparing a cathode layer, a neutron capture layer and an electron multiplication structure which are positioned in a vacuum state; the cathode layer, a neutron capture layer and an electron multiplication structure are arranged in sequence;
neutrons pass through the cathode layer and are captured by the neutron capture layer, generating electrons;
the electrons enter the electron multiplication structure under the combined action of the cathode layer and the electron multiplication structure, and the electron multiplication detection structure detects neutrons through multiplication.
1. The area of the neutron capture layer of the neutron detection cathode of the embodiment of the invention can be unlimited, and the geometrical structure of the detector used specifically depends on the development of the vacuum technology;
2. it should be understood that photocathodes in various photomultipliers can be directly replaced by neutron capture layers provided by the embodiment of the invention, and other processes are not changed, so that the photomultipliers can be directly converted into neutron electron multipliers;
3 the performance of the detector is mainly determined by the collection multiplication efficiency of the photomultiplier and the collection component, and is determined by the development of the industrial technology, so that the detector has large expandable space;
4. the signal reading mode can realize the rapid discrimination of the existence of large-area thermal neutron signals if the single anode is adopted; in case of multi-anode readout, position resolution can be achieved.
Of course, once the above description of representative embodiments is considered in great detail, those skilled in the art will readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to these specific embodiments, and such changes are within the scope of the principles of the present invention. Therefore, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims and their equivalents.
Claims (8)
1. A neutron detector, comprising:
a neutron detection cathode;
an anode or an array of anodes that collects electrons emitted from the neutron detection cathode; and
a vacuum vessel containing the neutron detection cathode and the anode or anode array;
wherein the neutron detection cathode comprises a thermal neutron capture material, and can convert incident thermal neutrons to generate directly detectable electrons, the neutron detection cathode comprising:
supporting a substrate;
an electrode layer disposed on the support substrate; and
a neutron capture layer disposed on the electrode layer, the electrode layer being located between the support substrate and the neutron capture layer; the neutron capture layer comprises a neutron capture material, and electrons are released after the neutron capture material captures neutrons;
wherein the support substrate is made of neutron transmission material,
neutrons are incident on the neutron-capture layer from a direction of the neutron-capture layer toward the support substrate, and electrons generated by the neutron-capture layer are released from the support substrate toward the neutron-capture layer.
2. The neutron detector of claim 1, wherein the neutron capture layer is a coating comprising a compound of gadolinium.
3. The neutron detector of claim 1, wherein the neutron capture layer is a gadolinium doped resistive coating.
4. The neutron detector of claim 1, wherein the neutron capture layer has a sheet resistance of a semiconductor thin film, and the electrode layer provides a voltage to the neutron capture layer to form an electric field, and the emitted electrons are collected by the electric field.
5. The neutron detector of claim 1, wherein the support substrate of the neutron detection cathode is part of an enclosure of the vacuum vessel.
6. A neutron detector, comprising:
a neutron detection cathode;
an electron multiplier for cascade-multiplying electrons emitted from the neutron detection cathode;
an anode or an anode array that collects secondary electrons emitted from the electron multiplier section; and a vacuum vessel housing the neutron detection cathode, the electron multiplier section, and the anode or anode array;
wherein the neutron detection cathode comprises a thermal neutron capture material, and can convert incident thermal neutrons to generate directly detectable electrons, the neutron detection cathode comprising:
supporting a substrate;
an electrode layer disposed on the support substrate; and
a neutron capture layer disposed on the electrode layer, the electrode layer being located between the support substrate and the neutron capture layer; the neutron capture layer comprises a neutron capture material, and electrons are released after the neutron capture material captures neutrons;
wherein the support substrate is made of neutron transmission material,
neutrons are incident on the neutron-capture layer from a direction of the neutron-capture layer toward the support substrate, and electrons generated by the neutron-capture layer are released from the support substrate toward the neutron-capture layer.
7. The neutron detector of claim 6, wherein the support substrate of the neutron detection cathode is part of an enclosure of the vacuum vessel.
8. A method of neutron detection, comprising the steps of:
preparing a support substrate, a cathode layer, a neutron capture layer and an anode which are positioned in a vacuum container; the cathode layer, the neutron capture layer and the anode are sequentially arranged, the cathode layer is attached to the neutron capture layer, and the cathode layer is arranged on the support substrate; the neutron capture layer is disposed on the cathode layer, the cathode layer being between the support substrate and the neutron capture layer; the support substrate is made of a neutron transmission material, the neutron capture layer comprises a neutron capture material, and the neutron capture material is used for releasing electrons after capturing neutrons;
thermal neutrons are incident on the neutron capture layer from the neutron capture layer towards the support substrate, are captured by the neutron capture layer, and generate electrons to be released from the support substrate towards the neutron capture layer;
the electrons are collected and detected by the anode under the combined action of the cathode layer and the anode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711106734.8A CN107884809B (en) | 2017-11-10 | 2017-11-10 | Neutron detector and neutron detection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711106734.8A CN107884809B (en) | 2017-11-10 | 2017-11-10 | Neutron detector and neutron detection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107884809A CN107884809A (en) | 2018-04-06 |
| CN107884809B true CN107884809B (en) | 2020-09-15 |
Family
ID=61780102
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711106734.8A Active CN107884809B (en) | 2017-11-10 | 2017-11-10 | Neutron detector and neutron detection method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107884809B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109633734B (en) * | 2018-12-24 | 2023-01-31 | 上海集成电路研发中心有限公司 | Device and method for detecting neutron content in ion implantation cavity |
| CN110567814B (en) * | 2019-08-26 | 2024-02-20 | 中国科学院地质与地球物理研究所 | Neutron imaging method for triaxial mechanical test of natural gas hydrate sediment |
| CN110988971B (en) * | 2019-12-30 | 2022-02-22 | 中国科学院高能物理研究所 | Wide-energy-spectrum white-light neutron resonance photography detector and detection method |
| CN112068187B (en) * | 2020-09-03 | 2023-03-21 | 中国科学院高能物理研究所 | High-sensitivity thermal neutron detector |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101924007A (en) * | 2009-06-10 | 2010-12-22 | 中国科学院高能物理研究所 | Photomultiplier |
| CN101995581A (en) * | 2009-08-28 | 2011-03-30 | 中国科学院高能物理研究所 | Gadolinium-doped resistive plate and detector formed thereby |
| CN102313898A (en) * | 2010-06-30 | 2012-01-11 | 清华大学 | Thermal neutron detector and manufacturing method thereof |
| CN102565846A (en) * | 2011-12-30 | 2012-07-11 | 清华大学 | Honeycomb-type thermal neutron detector |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8507872B2 (en) * | 2010-03-23 | 2013-08-13 | Nova Scientific, Inc. | Neutron detection |
| US9116246B2 (en) * | 2011-04-07 | 2015-08-25 | Stc.Unm | Thermal neutron detectors based on gadolinium-containing nanoscintillators |
| US8912484B2 (en) * | 2012-03-28 | 2014-12-16 | Schlumberger Technology Corporation | Photomultipler-based neutron detector |
| CN205941926U (en) * | 2016-08-24 | 2017-02-08 | 中国工程物理研究院核物理与化学研究所 | Neutron detector based on fission collecting of electro principle |
-
2017
- 2017-11-10 CN CN201711106734.8A patent/CN107884809B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101924007A (en) * | 2009-06-10 | 2010-12-22 | 中国科学院高能物理研究所 | Photomultiplier |
| CN101995581A (en) * | 2009-08-28 | 2011-03-30 | 中国科学院高能物理研究所 | Gadolinium-doped resistive plate and detector formed thereby |
| CN102313898A (en) * | 2010-06-30 | 2012-01-11 | 清华大学 | Thermal neutron detector and manufacturing method thereof |
| CN102565846A (en) * | 2011-12-30 | 2012-07-11 | 清华大学 | Honeycomb-type thermal neutron detector |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107884809A (en) | 2018-04-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107884809B (en) | Neutron detector and neutron detection method | |
| Crouthamel et al. | Applied gamma-ray spectrometry | |
| Pietropaolo et al. | Neutron detection techniques from μeV to GeV | |
| US7333701B1 (en) | Neutron detection | |
| WO2007013630A1 (en) | Microchannel plate, gas proportional counter and imaging device | |
| Dangendorf et al. | Progress in ultrafast CsI-photocathode gaseous imaging photomultipliers | |
| US2681416A (en) | Neutron scintillation counter | |
| Oed | Detectors for thermal neutrons | |
| Pan et al. | High detection efficiency neutron sensitive microchannel plate | |
| US8431906B2 (en) | Fast neutron detector having an open-structured hydrogenous radiator | |
| Francke et al. | Novel position-sensitive gaseous detectors with solid photocathodes | |
| JP2010286316A (en) | Optical detector | |
| Séguin et al. | Radiation-hardened x-ray imaging for burning-plasma tokamaks | |
| Breskin | Photon detectors for the 21st century | |
| Seitz et al. | Modern Neutron Detectors with Fast Timing Resolution | |
| Mörmann | Study of novel gaseous photomultipliers for UV and visible light | |
| CN220584409U (en) | Structure for improving conversion efficiency and spatial resolution of fast neutron detector | |
| Variale | Neutron Imager and Flux Monitor Based on Micro Channel Plates (MCP) in Electrostatic Mirror Configuration | |
| Tremsin et al. | High efficiency angular selective detection of thermal and cold neutrons | |
| Albayrak-Yetkin et al. | Secondary Emission Calorimetry: Fast and Radiation-Hard | |
| Tokanai et al. | Soda-glass capillary plate gas detector | |
| Breskin et al. | Large-area high-resolution thermal neutron imaging detectors | |
| Martinengo et al. | Position Sensitive Gaseous Photomultipliers | |
| Nappi | RICH detectors | |
| Mortonn | Recent developments in the scintillation counter field |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |