KR100549693B1 - A neutron-nanotube using carbon nanotubes, and a neutron detector using that - Google Patents

Abstract

The present invention relates to a neutron nanotube using carbon nanotubes having high efficiency characteristics, and a neutron detection device capable of detecting neutrons with high sensitivity using the same.

The purpose of the present invention is to provide a highly efficient and highly sensitive neutron nanotube for realizing a neutron detection device, and to provide a neutron detection device having a high sensitivity and a fast response time using the same.

The structure of the present invention is a neutron nanotube using a carbon nanotube, a neutron nanotube using a neutron conversion layer is formed on the outer surface of a plurality of carbon nanotubes grown on the lower surface of the substrate to emit electrons by neutron reaction and a neutron detection device using the same Its technical features.

Carbon nanotube, neutron, nuclear reaction, signal processing circuit board, neutron nanotube

Description

A neutron-nanotube using carbon nanotubes, and a neutron detector using that}             

1 is a conceptual diagram of neutron nanotubes using carbon nanotubes according to the present invention;

2A is a schematic cross-sectional view of a neutron detection device according to the present invention,

2b is another schematic cross-sectional view of a neutron detection device according to the present invention;

3 is an enlarged photograph of carbon nanotubes.

<Description of the symbols for the main parts of the drawings>

(1): neutron (2): substrate

(3): drifting electrode (4a): carbon nanotube

(4b): Neutron Reaction Layer (4c): Electron Emission Layer

(5): secondary electron (6): microchannel plate

(8): signal processing circuit board (7): electron collecting electrode

(9): Neutron deceleration material (10): Voltage application means

The present invention relates to a neutron nanotube using carbon nanotubes having high efficiency characteristics, and a neutron detection device capable of detecting neutrons with high sensitivity using the same, in particular, while passing through a plurality of carbon nanotubes in which incident neutrons are concentrated It is captured by the neutron conversion layer formed on the outer surface of the nanotubes to emit charged particles, and the emitted charged particles induce secondary electron emission while passing through the neutron nanotubes, so that the emitted electronic signals can be efficiently obtained, The present invention relates to neutron nanotubes using carbon nanotubes that can be usefully applied in fusion furnaces, nuclear power plants, industrial industries, etc., and also to high sensitivity neutron detection devices using such neutron nanotubes.

In the related art, the neutron detector mainly uses a nuclear reaction in which neutrons and substances in the detector react to release charged particles, and the types thereof include proportional counters or boron (B) coated counters using ³ He, ¹⁰ B, and the like. Semiconductor and scintillation detector using ⁶ Li, fission chamber using fission materials such as ²³⁵ U, ²³⁸ U, ²³⁹ Pu, and SPND (Self Powered Neutron Detector) using β-ray emitter such as ¹⁰³ Rh, ⁵¹ V There is this.

Among the neutron detectors, a neutron detector having a thin coating structure of a solid nuclear reactant increases the possibility that neutrons are trapped as the thickness of the nuclear reactant increases, but the likelihood that charged particles are released out of the nuclear reactant decreases. The energy of the whole particles decreases, which causes a decrease in the neutron detection efficiency. Therefore, the neutron detector using the solid neutron reaction material has a problem that the detection efficiency is low and therefore not suitable for high sensitivity neutron detection.

An object of the present invention for solving the above problems is to provide a neutron detection device with a high response time while detecting a neutron.

In addition, another object of the present invention to provide a high efficiency, high sensitivity neutron nanotubes for the realization of the neutron detection device as described above.

The object of the present invention and the neutron nanotubes using carbon nanotubes, and neutrons using the same neutron conversion layer is formed on the outer surface of the plurality of carbon nanotubes grown on the lower surface of the substrate to form a neutron conversion layer that emits electrons by neutron reaction By providing a detection device.

When described in detail with reference to the accompanying drawings, the configuration and the operation of the embodiment of the present invention to achieve the object as described above and to perform the task for eliminating the conventional drawbacks.

The present invention constitutes neutron nanotubes that cause nuclear reactions and emit electrons with incident neutrons using carbon nanotubes (CNTs), and provide a neutron detection device using these neutron nanotubes. In particular, the core of the technical idea is to form a neutron conversion layer that emits electrons by nuclear reaction with neutrons on the outer surface of carbon nanotubes.

Recently, high-purity carbon nanotubes grown vertically on the lower surface of a substrate using thermal chemical vapor deposition, plasma enhanced chemical vapor deposition, and the like are shown in FIG. 3. Has been studied in various fields such as electron emitter, vacuum fluorescent display (VFD), white light source, field emission display (FED), and it is 10-100 times stronger than steel, and its length is tens of nm-number. m and an outer diameter of 2.5-200 nm, which is used as a neutron nanotube for directly converting incident neutrons into electrons in the present invention.

Neutron nanotubes according to the present invention is characterized in that the neutron conversion layer for absorbing neutrons to emit electrons formed on the outer surface around the carbon nanotubes.

FIG. 1A illustrates a conceptual diagram of neutron nanotubes using carbon nanotubes according to the present invention. As shown, neutron nanotubes include carbon nanotubes 4a grown vertically on a lower surface of a substrate 2 and the It is formed of a neutron conversion layer that causes nuclear reactions and emits electrons with neutrons incident on the outer surface of carbon nanotubes.

The neutron converting layer is composed of an inner neutron reaction layer 4b and an outer electron emitting layer 4c.

That is, two layers were formed, an inner neutron reaction layer and an outer electron emission layer.

A drifting electrode 3 is deposited on the upper surface of the substrate 2, a catalyst metal film is formed on the lower surface of the substrate 2, and the carbon nanotubes are vertically deposited.

The carbon nanotubes 4a have a diameter D of about 10-100 nm, and the length L of the carbon nanotubes 4a is about 10-100 μm in order to increase the detection efficiency for the incident neutron.

This carbon nanotube serves as a rigid support for the neutron nanotube material for converting neutrons into electrons, and the neutron conversion layer material has about 10-100 nm of neutron reaction layer 4b around the carbon nanotube 4a. It is coated with a thickness of, the electron emission layer (4c) is coated on it to form a neutron conversion layer.

As such, a neutron reaction layer and an electron emission layer outside thereof are formed on the outer surface of the carbon nanotubes. Preferably, the neutron reaction layer 4b is boron (B), a boron compound, or lithium (Li). ), A lithium compound, or a nitrogen (N) compound, or any one of neutrons incident to (n, α) or a material capable of causing a nuclear reaction (n, p), and the electron emission layer 4c. It is preferable to form one of cesium iodide (CsI), cesium bromide (CsBr), potassium chloride (KCl), potassium iodide (KI) and magnesium oxide (MgO), which are excellent in the emission effect of silver secondary electrons.

The other material capable of forming the neutron reaction layer 4b may be any one of uranium (U), a uranium compound, a plutonium, and a plutonium compound, or any material that causes a nuclear fission reaction with an incident neutron.

After neutrons in various energy ranges from 0.01 eV to several hundred MeV used in accelerators, nuclear power plants, fusion reactors, basic science and industry are decelerated into thermal neutrons through moderators, neutron nanotubes using carbon nanotubes according to the present invention. When incident on the neutron reaction layer (4b) of (n, α) or (n, p) mainly causes a nuclear reaction or fission reactions, and charged particles such as α particles, protons, fission products and the like.

Figure 1a is an example of the case where the neutron reaction layer is formed of a nitrogen compound, and (n, p) nuclear reaction with the incident neutrons are generated, ¹⁴ C of 42 keV and protons ( ¹ p) of 585 keV are generated, the neutrons in opposite directions It runs between the nanotubes. The (n, p) nuclear reaction of the nitrogen and neutron is as follows.

¹⁴ N + ¹ n → ¹⁴ C + ¹ p (E _C = 42 keV, E _p = 585 keV)

The neutron reaction layer is coated around a carbon nanotube having a thin, long and dense structure, and thus the incident neutron passes through a plurality of neutron nanotubes, thereby providing a long neutron reaction path, thereby increasing detection efficiency for neutrons.

The charged particles generated when the neutron is trapped in the neutron reaction layer collide with the electron emission layer 4c of the adjacent carbon nanotubes to generate a plurality of secondary electrons, and the secondary electrons are again inside the electron emission layer. Generates ionization and generates a large number of electrons.

The thickness of the electron-emitting layer is preferably about 10 to 100 nm in consideration of the range of electrons. Some of the electrons 5 generated by the secondary electrons have excellent surface barrier energy of the electron-emitting layer. And is released into the open passage between the carbon nanotubes.

The substrate 2 of the carbon nanotube of the present invention has a drift electric field in the longitudinal direction of the carbon nanotube in order to efficiently collect electrons emitted in the open passage between the carbon nanotubes in the electron collecting electrode 7. It is more effective to add the drift electrode 3 and the voltage applying means 10 so as to be caught.

By using the neutron nanotubes using the carbon nanotubes according to the present invention as described above it is possible to implement a high sensitivity neutron detection device.

The neutron detection apparatus according to the present invention has a moderator 9 for decelerating neutrons, a neutron nanotube using the carbon nanotubes, and an output terminal of the neutron nanotubes (the tip of the carbon nanotubes) as shown in FIG. 2A. An electron collecting electrode 7, a drifting electrode 3, and a voltage applying means 10 are provided to collect the electronic signals emitted from the neutron nanotubes spaced apart from each other, and a signal processing circuit board 8 is provided on the electron collecting electrodes. It is characterized by the addition.

Figure 2b is a cross-sectional view of another embodiment of the neutron detection apparatus using a neutron nanotube according to the present invention, as shown, the neutron detection apparatus according to the present embodiment is on the moderator 9 and the upper surface of the substrate for reducing the neutron Electrons emitted by being slightly spaced apart from the drift electrode 3, the voltage applying means 10, the neutron nanotubes 4 using the carbon nanotubes, and the output terminal (the tip of the carbon nanotubes) of the neutron nanotubes are formed. A microchannel plate 6 for amplification is provided, and an electron collecting electrode 7 is provided at a distance from the output terminal of the microchannel plate to collect the electronic signals emitted from the microchannel plate. It is characterized in that the signal processing circuit board 8 is added.

In the operating principle of the neutron detection device of the present invention configured as described above, the incident neutron is decelerated into a thermal neutron by the moderator, and after causing a nuclear reaction with the neutron reaction layer 4b of the neutron nanotube, the charged particles are released and released. The charged particles emit electrons while passing through the electron emission layer 4c of the neutron nanotubes.

The emission electrons 5 move along the electric field and can be collected directly from the electron collection electrode 7, and the electron signal detects flux of neutrons through a signal processing circuit connected to the collection electrode.

Meanwhile, when the microchannel plate 6 is placed between the neutron nanotube 4 and the collection electrode 7 using the carbon nanotubes, the emission electrons 5 flow into the channel of the microchannel plate and electron amplification occurs. At the collecting electrode, an amplified signal can be obtained.

Within a supply voltage of 1000 V of the microchannel plate, the gain of the microchannel plate is about 10 ⁴ , and the inside of the neutron detector may have a vacuum of 10 ⁻⁵ torr or less. On the other hand, the neutron detection apparatus using the neutron nanotubes operates in a vacuum and detects an electronic signal, so the operation speed is very fast.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

The present invention as described above forms a neutron conversion layer capable of capturing neutrons and emitting electrons on the outer surface of the carbon nanotubes so as to effectively emit incident neutrons as electrons, by using this to accurately measure neutrons at high speed. It is a useful invention having the advantage that the reliability of neutron detection can be greatly improved by making it possible to do so.

Claims (10)

delete On the outer surface of the carbon nanotubes (4a) is formed a neutron conversion layer that causes a nuclear reaction with neutrons and emits electrons, The neutron converting layer is composed of an inner neutron reaction layer 4b and an outer electron emitting layer 4c, The neutron reaction layer 4b may cause a nuclear reaction of boron (B), boron compound, lithium (Li), lithium compound, nitrogen (N), incident neutrons (n, α) or (n, p) One selected from the group consisting of a material selected from the group consisting of uranium (U), uranium compounds, plutonium, plutonium compounds, and any one selected from the group consisting of incident neutrons and nuclear fission reactions, The electron-emitting layer 4c is formed of any one selected from the group consisting of cesium iodide (CsI), cesium bromide (CsBr), potassium chloride (KCl), potassium iodide (KI), and magnesium oxide (MgO). Neutron nanotubes using nanotubes. delete delete delete delete In the neutron detection device, Boron (B), Boron Compound, Lithium (Li), Lithium Compound, Nitrogen inside to cause nuclear reaction and neutron reaction on the outer surface of the plurality of carbon nanotubes 4a grown on the lower surface of the substrate 2 (N) compounds, formed from a crowd of neutrons that are incident and (n, α) or (n, p) that can cause nuclear reactions, or uranium (U), uranium compounds, plutonium, plutonium compounds, incident A neutron nanotube having a neutron reaction layer 4b formed of any one selected from the group consisting of neutrons and a fission reaction material, and a neutron conversion layer composed of an outer electron emission layer 4c; A drifting electrode 3 formed on the upper surface of the substrate 2 so as to have a drifting electric field in the longitudinal direction of the carbon nanotubes; Voltage applying means (10) for applying a voltage to the drift electrode; An electron collecting electrode 7 disposed spaced apart from an output terminal of the neutron nanotube (a tip of the carbon nanotube) and collecting an electron signal emitted from the output terminal of the neutron nanotube; It is coupled to the signal processing circuit board (8) which is installed in the lower portion of the electron collecting electrode to process the collected signal, A neutron detection device using neutron nanotubes, characterized in that it comprises a neutron deceleration material (9) installed to surround the circumference of the combined device. The method of claim 7, wherein A neutron nanotube further comprises a microchannel plate 6 for amplifying the electrons emitted by being spaced apart between the output terminal of the neutron nanotube (a tip of the carbon nanotube) and the electron collecting electrode 7. Neutron detection device using. delete The method of claim 7, wherein The neutron reduction material 9 for converting fast neutrons into thermal neutrons is neutron nano, characterized in that formed from any one selected from the group consisting of hydrogen containing materials such as paraffin, polyethylene, H ₂ O, ZrH ₂ , and graphite (C). Neutron detection device using a tube.

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