RU2626324C2 - Device for energy fission conversion - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: device for converting the energy of the nuclear fission energy is generated from the photoelectric converters of light emission generated by irradiation of the luminescent material with the products of the nuclear reaction. Herewith the space is filled between the photoelectric converters by the alternating volumes of the radioactive material and the phosphor. The characteristic size of the radioactive material volumes does not exceed the mean free path of the emitted particles therein or, at least, comparable thereto, and the characteristic size of the phosphor volumes is not smaller than the mean free path of the emitted particles in the phosphor.

EFFECT: increasing the output device power due to uniform distributing radioactive substances in the phosphor medium and limitating the characteristic sizes of the phosphor and the radioactive substance.

7 cl, 6 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to the field of energy sources that convert the energy of nuclear reactions, in particular beta decay energy, using semiconductor converters.

BACKGROUND

There is a significant number of devices that convert the energy of radioactive decay into electricity through semiconductor converters of various designs. Some devices use semiconductor converters, in which one way or another creates a developed surface of the converter body itself in the form of pores or a specially formed structure, and the radioactive substance is located directly in the body of the semiconductor converter. It can be located on the entire surface or its part and / or be distributed directly in the volume of the transducer.

The most typical constructions can be considered devices described, for example, in the following information sources: RU 2461915 C1 from 09/20/2012, RU 2452060 C2 from 05/27/2012, US 6774531 A1 from 08/10/2004.

Various radioactive materials are used as the primary source of energy in these devices, but devices operating on the nickel-63 and tritium isotopes are considered the most promising. This is due to the "pure" beta decay of the said isotopes, as well as the relatively low energy of beta particles, eliminating the risk of radiation damage to the base (body) of the semiconductor converter and, accordingly, degradation of the output power of the entire device.

At the same time, the use of radioactive sources with relatively low particle energies means that special measures must be taken to prevent the effect of self-absorption of particles in the layer of radioactive material, actually limiting the characteristic size of solid radioactive sources. The mean free path of intrinsic beta particles in nickel-63, for example, is only 0.1 ÷ 0.2 μm, which limits the power of the entire device. A typical dependence of the number of emitted particles on the thickness of a continuous layer of a radioactive source is nonlinear (tends to saturation) and is shown in FIG. one.

That is, devices with a combined semiconductor converter and a radioactive source have a limiting output specific power.

In fact, the implementation of such a design is possible only with the use of a gaseous radioactive source, which gives limitations on the types of radioactive materials used.

Another constructive variant of the devices involves an intermediate conversion of decay energy into radiation using the corresponding phosphor (cathodoluminophore) and its subsequent conversion into electrical energy by a semiconductor converter. In this case, both gaseous and solid substances can act as a radioactive source.

A device is known, disclosed in RU 2202839 C2 dated 04/20/2003, in which a mirror layer and sections of a phosphor layer or sections of a phosphor layer with sections of a phosphor layer deposited on them are applied to the inner surface of the bulb, the bulb being filled with a slightly radioactive inert gas with the possibility of interaction of particles of natural radioactive the decay of isotopes of an inert gas with a phosphor and with the possibility of separation of the photon flux, and the conversion device is made in the form of semiconductor solar cell elements.

The disadvantages of this device include the fact that, on the one hand, only a thin layer of the applied phosphor is exposed to radioactive particles, and on the other hand, not all particles can reach the phosphor layer due to scattering and absorption in the gas.

Also known is a system and method for a self-charging battery, disclosed in US 8350520 B2 of 01/08/2013, where a solid source is used. In this case, the initial energy of beta particles from the decay of Sr-90 is converted into light using the surrounding radioactive source of the phosphor (scintillator), and the light itself is converted into electrical energy using a photoelectric converter. The radioactive source itself is located along the axis of the cylinder, the transducer is located on the surface of the cylinder, and the scintillator (phosphor) fills the cylinder body. The disadvantages of this device include the fact that the compact location of the radioactive source does not exclude the effect of self-absorption of emitted particles in the source itself, which reduces the overall power of the device.

A device is known (US 5721462A dated 02.24.1998) in which small volumes of a phosphor are distributed in a gel containing a radioactive substance. The gel is applied to the surface of a photoconverter that generates electrical energy. The disadvantages of this device include the possibility of uncontrolled absorption in the gel itself.

The closest in technical essence is the device (US 4242147 A dated 12.30.1980), in which the energy is generated by photoelectric converters from light radiation created by irradiating a luminescent material with nuclear reaction products, the space between the photoelectric converters being filled with alternating volumes of radioactive material and a phosphor, which, in turn are enclosed in containers with holders. Holders and containers can be made of transparent material.

The specified design has the following disadvantages. Firstly, the presence of containers significantly attenuates the flow of particles reaching the luminescent material due to absorption in the container material. Secondly, these volumes are quite large, far exceeding the mean free path of emitted particles, which also leads to significant self-absorption.

Known technical solutions do not reflect the geometric characteristics of the structures associated with the range of emitted particles in the radioactive material itself and in the phosphor.

SUMMARY OF THE INVENTION

The objective of the present invention is to increase the efficiency of conversion of nuclear decay energy due to the uniform distribution of the radioactive substance in the phosphor medium and limiting the characteristic sizes of the radioactive substance and phosphor.

The technical result of the present invention is to increase the output power of the device.

The technical result is achieved by the fact that energy is generated by photoelectric converters from light radiation created by irradiating a luminescent material with nuclear reaction products, the space between the photoelectric converters being filled with alternating volumes of radioactive material and a phosphor, while the characteristic size of the volumes of radioactive material does not exceed the mean free path of emitted particles in him, or at least comparable to him, and the characteristic size of the volumes of lumi the nophora is not less than the mean free path of the emitted particles in the phosphor.

In this context, the characteristic size of the volume is the average diameter (for the case of spherical) or the smaller of the geometric dimensions for other (for example, rectangular) volumes.

Given the geometric dimensions of the volumes of radioactive material, most of the particles emitted by it will come out of these volumes, that is, losses on self-absorption will be minimal.

With the indicated geometric dimensions of the phosphor volumes, most of the emitted particles can be absorbed in them, providing an increased output of light photons, which increases the output power of the device.

Additional benefits can be achieved by using a radioactive source made of a chemical compound of a radioactive material that is transparent to the main radiation of the phosphor. In this case, the radioactive material will not weaken (obscure) the light flux to the photoconverters. A phosphor, in the general case, should have high transparency for intrinsic radiation and the maximum technically possible energy efficiency for converting particle energy into radiation.

In addition, alternating volumes of radioactive material and phosphor can form at least one light emitting layer, the light radiation of which is composed of the glow of individual volumes of the phosphor.

Under the light radiation refers to the radiation of the phosphor in any wavelength range

In addition, in the case of the embodiment, when at least two light-emitting layers are formed, the photoelectric converters may be located between these layers.

In addition, the light-emitting layers may include excellent radioactive materials and phosphors.

In this case, photoelectric converters can have two-sided sensitivity.

The combination of the above parameters eliminates the phenomenon of self-absorption and provides a linear dependence of the output power of the device on the mass of radioactive material.

The device can use either a solid or a liquid or gaseous state of a radioactive compound (element) or a mixture thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

In FIG. Figure 1 shows a comparison of electrons emitted by a nickel-63 film as a function of layer thickness h (theoretical calculation).

The ordinate axis is the number of electrons, relative units.

The abscissa indicates the thickness of the nickel layer (μm).

Ntot (h) is the number of electrons released from a continuous layer of nickel.

Ndiss (h) is the number of electrons under the assumption that the nickel film is divided into many infinitely small volumes.

In FIG. Figures 2-6 show device options for converting decay energy.

NOTATION

1 - Radioactive material, the characteristic size of the volume of which does not exceed the mean free path of the emitted particles in it, or, at least, is comparable with it.

2 - Phosphor, the characteristic size of the volume of which is not less than the mean free path of the emitted particles in it.

3 - The zone in which the energy of atomic decay is converted, comparable to the mean free path of the particles formed during the decay.

4 - Alternating volumes of radioactive material and phosphor - light-emitting layer.

5 - Photoelectric Converter.

DETAILED DESCRIPTION OF THE INVENTION

An electric power source (including a nuclear energy conversion device) contains a photon flux source, and a device for converting radiation energy into electrical energy - semiconductor photoelectric converters. To transmit electric current from photovoltaic converters to the energy consumer, wires are provided.

Energy is generated by photoelectric converters from light radiation created by irradiating a luminescent material with nuclear reaction products. The space between the photoelectric converters is filled with alternating volumes of radioactive material and a phosphor, while the characteristic size of the volumes of radioactive material does not exceed the mean free path of emitted particles in it, or at least is comparable with it, and the characteristic size of the volumes of the phosphor is not less than the mean free path of emitted particles in the phosphor.

The radioactive source may be made of a chemical compound of a radioactive material that is transparent to the main radiation of the phosphor, for example, its corresponding salt or oxide. A phosphor, in the general case, should have high transparency for intrinsic radiation and the maximum technically possible energy efficiency for converting particle energy into radiation.

The spectral characteristic of the photoconverter, in turn, should ensure the conversion of phosphor radiation with the highest possible efficiency.

Depending on the choice of a particular radioactive material, the implementation of the nuclear energy conversion device of the proposed design can be carried out in several versions. The operation of some of the possible options is illustrated by drawings.

In the embodiment of the device shown in FIG. 2, the grains of the phosphor 2 are surrounded by a thin layer of radioactive substance 1, the thickness of which is small enough to completely transmit particles emitted during atomic decay, for example electrons. These particles penetrate the phosphor grain, while in zone 3, comparable to the mean free path of the particles, the particle energy is converted into light energy. Each phosphor particle having a size larger than zone 3 emits its own radiation, which passes through both the phosphor particle transparent to its own radiation and through a thin layer of radioactive material. Since the layer of radioactive substance is thin, each particle of the phosphor emits a small amount of light energy. Of the many such particles, light-emitting layers 4 are assembled, where the light energy of the individual particles is added up and the total light flux is sent to the photoelectric converter 5.

Due to the fact that the thickness of the layer of radioactive substance is less than the mean free path of particles in the layer of radioactive material, there is no loss of particle energy due to self-absorption. On the other hand, due to the fact that the phosphor grain has a diameter greater than the mean free path of the particles in the phosphor itself, all emitted particles participate in the process of creating light energy. By reducing losses, the device has an increased efficiency ratio.

The coating of phosphor grains with a radioactive transparent material occurs after the formation of the phosphor itself. The coating may be carried out by any method known in the art, for example by precipitation of a radioactive substance from a supersaturated solution. This design is suitable for a radioactive substance that does not cause the appearance of radiation defects in the base of a semiconductor photoconverter, for example, nickel-63 compounds.

In the embodiment of the device shown in FIG. 3, the radioactive particles 1 are placed inside the grains of the phosphor 2, including at the stage of manufacture of the phosphor itself. Such an introduction of a radioactive substance can be implemented by known methods, for example, by sintering phosphor particles by introducing additional radioactive material into the charge. The particles of the transparent radioactive material 1 are surrounded by zone 3, in which the atomic decay energy is converted, comparable to the mean free path of the particles produced by the decay, and placed in the phosphor grain 2. Many of these grains form light-emitting layers 4, and the light flux from the grains is converted using photoelectric converters 5 into electrical energy.

This design is different from that shown in FIG. 2 also by the fact that it allows the use of radioactive compounds that can cause radiation damage (defects) in the base of a semiconductor photoconverter, for example Gd 148.

A particular case of this embodiment is the design shown in FIG. 4. Here, the phosphor is made in the form of a solid plate 2, in which particles of a transparent radioactive material are distributed 1. Techniques are known for manufacturing integral phosphor plates, for example, growing a single crystal. Together, this combination forms a light-emitting layer 4, the radiation of which is converted by the photoconverters 5. In this design, there are no losses due to scattering from numerous reflections from the phosphor grains, which gives it advantages over the design shown in FIG. 3. In this embodiment, the characteristic distance of the phosphor is the average distance between the particles of the radioactive substance.

The protection of the photoconverter from radiation damage is enhanced in the embodiment of the device shown in FIG. 5. Here, the photoelectric converter 5 and the layer of transparent radioactive substance 1 are separated by thick layers with a thickness greater than the mean free path of the particles by the layers of a continuous solid phosphor 2 (scintillator). The thickness of the layer of radioactive substance 1 is less than the mean free path of the particles in it, so it can be considered a small volume in terms described above. In this case, the photoelectric transducer 5 is guaranteed to be protected from high-energy particles generated by atomic decay, which allows the use of radioactive materials with high energy of emitted particles, for example Sr-90.

Each variant of the device may contain a different number of light-emitting layers, including one layer.

Moreover, the present invention includes the possibility of arranging two or more light-emitting layers of various radioactive materials with different properties, for example, high and low energy of emitted particles, as illustrated in FIG. 6. Here can be combined for sharing, for example, compounds of strontium-90 and nickel-63. Accordingly, phosphors can be different both in composition and in geometric parameters. For example, one of the light-emitting layers 4 can be made by separating the first high-energy radioactive material 1 with a monolithic continuous layer of the first phosphor 2. Another light-emitting layer 4 consists of particles of a second phosphor with particles of a transparent second radioactive material.

An additional advantage in this embodiment is additional radiation protection by the outer layers of the phosphor of both the photoconverters and the space outside the specified device, including from high-energy photons (x-ray radiation).

In all device variants, the space between particles and (or) layers and photoelectric converters can be filled with an optical medium with a refractive index approaching the refractive index of the phosphor to eliminate light scattering losses.

Additional benefits can be achieved by using photoconverters with two-sided sensitivity, creating multilayer structures, as shown in FIG. 2. Moreover, each photoconverter located between the luminescent layers is in conditions of increased energy illumination (irradiation), which increases the conversion efficiency of the photoconverter in comparison with its one-sided version.

The above description illustrates and in no way limits the present invention. Although the present invention has been described with reference to exemplary embodiments, it should be understood that the explanations used herein are illustrative and not restrictive. Changes may be made within the scope of the appended claims. Although the present invention is described herein with reference to specific means, materials and embodiments, the present invention is not limited to the details disclosed herein; rather, the present invention extends to all functionally equivalent structures that fall within the scope of the appended claims.

Claims (7)

1. A device for converting nuclear decay energy, where the energy is generated by photoelectric converters from light radiation created by irradiating a luminescent material with nuclear reaction products, the space between the photoelectric converters being filled with alternating volumes of radioactive material and a phosphor, while the characteristic size of the volumes of radioactive material does not exceed the length of the free the path of emitted particles in it, or at least comparable to it, and the characteristic p The size of the phosphor is not less than the mean free path of the emitted particles in the phosphor. 2. The device according to claim 1, characterized in that the alternating volumes of the radioactive material and the phosphor form at least one light emitting layer, the light radiation of which is composed of the glow of individual volumes of the phosphor. 3. The device according to claim 1, characterized in that the alternating volumes of the radioactive material and the phosphor form at least two light-emitting layers, the light emission of which is composed of the glow of individual volumes of the phosphor, and the photoelectric converters are located between the light-emitting layers. 4. The device according to p. 3, characterized in that the photoelectric converters have two-way sensitivity. 5. The device according to p. 3, characterized in that at least two light-emitting layers contain differing in characteristics radioactive materials and phosphors. 6. The device according to p. 5, characterized in that the photoelectric converters have two-sided sensitivity. 7. The device according to any one of paragraphs. 1-6, characterized in that the radioactive material is transparent to the main radiation of the phosphor.

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