RU154180U1 - DEVICE FOR DIRECT CONVERSION OF IONIZING RADIATION TO ELECTRICITY - Google Patents

Abstract

A device for converting ionizing radiation into electricity, consisting of conductors with a small and large atomic number, separated by an insulator layer, characterized in that the role of a conductor with a large atomic number is played by continuous chains of nanoparticles with close to spherical geometries, and as a conductor with a light the atomic number is liquid electrolyte, which creates an insulating double layer at the interface between the heavy and light conductors.

Description

The utility model relates to the field of methods for converting ionizing radiation into electricity.

Currently, due to acute climatic problems arising from the accumulation of carbon dioxide in the Earth’s atmosphere, the problem of replacing heat sources of electricity using the combustion of carbon-containing substances and providing at the moment the main energy consumption with alternative energy sources that do not produce carbon dioxide is becoming more and more acute. . Nuclear energy in this regard is one of the main alternatives that can provide not only household, but also industrial needs of the world's population. But the expansion of the use of this type of energy is hindered by two serious factors: the danger of accidents at nuclear power plants like the Chernobyl 1986 or Fukushima 2011, which led to extensive radioactive pollution of the environment, and the inevitable increase in the volume of radioactive waste from the operation of nuclear reactors. Therefore, the development of effective devices for the direct conversion of ionizing radiation into electricity is of particular relevance. On the one hand, the placement of such devices in the pools of the settling tanks of nuclear reactors, where the fuel elements (TVELs), which have expired during their life, and which have become very radioactive during their operation, can withstand the nuclear power plant as a backup source of electricity in case the reactor is shut down. The reliability of this kind of radiation generators should be significantly higher than the reliability of the diesel generators currently used to support reactor cooling systems. In particular, problems with diesel generators have become one of the main reasons for the increase in radioactive contamination in the area of Fukushima NPP, as due to their breakdowns and problems with the delivery of diesel fuel, the generators did not cool, and the cladding of the fuel elements melted due to overheating. Radiation generators do not contain moving parts and therefore are much more reliable in terms of breakdowns. On the other hand, their performance does not require fuel delivery.

Placing effective converters of radiation into electricity in radioactive waste storage facilities can not only solve the problems of energy supply of the storage facilities themselves, but also provide very cheap electricity to neighboring consumers. In this case, it is possible that as a result, radioactive waste as the main component of cheap energy supply will turn from the subject of intimidation of society into an object of market competition.

In addition, in many cases, it is necessary to provide remote energy consumers, working for a long time in isolated hard-to-reach places, with autonomous sources of electricity (spaceships, lighthouses, interplanetary stations, etc.). At present, radioactive short-lived isotopes are used for this, during the nuclear decay of which a whole series of high-energy particles and radiation are emitted. But in the current converters, radioisotope thermoelectric generators (RTGs) operate, where the radiation energy is first converted into heat, and then into electricity. Due to the two-stage conversion, the efficiency of RTGs does not usually exceed 7%. It can be expected that direct conversion devices will significantly increase this value.

To date, several types of devices for the direct conversion of ionizing radiation into electricity are known. So, for example, a device is known [patent US 2005/0077876 A1 publ. April 14, 2005], which converts the energy of ionizing radiation into electricity, consisting of several composite plates, which consists of successive layers of insulator-metal with a small atomic number - insulator - metal with a large atomic number. Layers of metal with a small atomic number are connected in parallel with each other and isolated from layers of heavy metal, also connected in parallel. A beam of ionizing radiation falls perpendicular to the surface of the plate. When passing through a plate, ionizing radiation is absorbed due to Compton scattering and the photoelectric effect, knocking electrons from the electron shells of atoms. The number of electrons knocked out from a heavy metal is greater than from a lighter metal, due to which a potential difference arises between them. An additional increase in the potential difference is achieved by the absorption of electrons knocked out of a heavy metal by layers of light metal.

The main disadvantage of the known device is that it has a low efficiency, which on the prototypes presented by the authors amounted to only one hundred thousandth of a percent. From the point of view of the use of nanostructures, of particular interest is another device for converting ionizing radiation into electrical energy [patent US 2010/0061503 A1, publ. 03/11/2010]. A characteristic feature of the device is that the elementary elements that convert radiation are nanoscale objects, such as nanolayers, nanoclusters and nanotubes, from conductors with a small and large atomic number, separated by an insulator layer and connected in a certain way to each other.

The main disadvantage of the device is the great technological difficulties that arise during its manufacture, associated with the need for nanoscale control of the structure of the converter and the need to carry out parallel or serial connection of all elementary converting "cells" to each other.

Closest to the solution of the problem of efficient conversion of ionizing radiation, namely short-wave electromagnetic radiation (X-ray and gamma-ray range), a useful model is presented, presented in RF patent RU 144220 publ. 08/10/2014 "Device for converting ionizing radiation into electrical energy", authors Ershov A.E., Klassen N.V., Kurlov V.N. In this device, a biomorphic matrix based on wood acts as a conductor with a small atomic number. In FIG. 1 shows a schematic diagram of this device for converting ionizing radiation into electrical energy. It consists of a microchannel matrix of a conductive material with a small atomic number (collector) (1). The surface of the microchannels is covered with a layer of insulator (2), while the channels themselves are filled with a conductor with a large atomic number (emitter) (3). Collector wires (4) are connected to the collector and to the emitter.

In the case when a liquid electrolyte containing heavy elements is used as a heavy conductor, a double charging layer arising at the interface between the electrolyte and the solid light conductor can be used as an insulator.

The main disadvantage of the prototype device is the cylindrical geometry of the microregions of a heavy conductor that absorbs ionizing radiation. With this absorber geometry, part of the fast electrons excited by the absorbed quanta moves in directions close to the axis of the cylinder and therefore is not able to cross the insulator layer and be injected into a light conductor, producing the charge transfer necessary for the converter to operate. Thus, the use of the cylindrical geometry of the transducer reduces its efficiency. In addition, filling the microchannels of the biomorphic matrix with a solid heavy conductor poses serious technological difficulties.

The technical result, which is claimed by the claimed utility model, consists in increasing the efficiency of devices for direct conversion of ionizing radiation into electricity, as well as improving manufacturability and a corresponding reduction in the cost of production of these devices due to the use of electrically conductive extra-long chains of spherical as primary absorbers of ionizing radiation nanoparticles playing the role of electron emitter, and placing them in liquid electro due to the contact potential difference, it has a positive charge with respect to these nanoparticles and, therefore, plays the role of a collector of electrons emitted from nanoparticles.

The principle of operation of this type of converter is shown in FIG. 2. A heavy nanoparticle is shown schematically on the left, where arrows indicate the possible directions of the outward emission of electrons excited by the absorption of an ionizing gamma ray. The same particle 3 is shown in the center and the location relative to its center of the insulating layer 2 and the light conductor 1 is indicated (in the case of using an electrolyte as a light conductor, insulator 2 can be a double electric layer between the electrolyte and the heavy conductor). The schematic arrangement of electrically interconnected nanoparticles forming a continuous chain is shown on the right. The spherical geometry of the nanoparticles provides a significant increase in the percentage of transition of electrons excited by gamma rays absorbed in the nanoparticles into a light conductor compared to the prototype, thereby increasing the efficiency of the converter of ionizing radiation into electricity.

The technical results set by the applicant are achieved in several ways. Firstly, nanoparticles of substances containing heavy chemical elements are used as ionizing radiation absorbers, while the electrolyte surrounding the nanoparticles consists of light elements, which ensures the predominant absorption of ionizing gamma radiation by nanoparticles. Secondly, the absorbing nanoparticles are interconnected in electrically conductive chains of a centimeter or more in length, which are placed in a liquid electrolyte having a positive contact potential difference relative to the chains of nanoparticles. Chains of nanoparticles are attached to the external electrode of the device, which, when exposed to the converted ionizing radiation, is charged positively, and the electrolyte is connected to the electrode charged negatively when irradiated. The large length of these chains of nanoparticles creates the conditions for the effective return of electrons emitted from the nanoparticles to the electrolyte through an external circuit with useful work with a minimum number of contact compounds and a minimum internal resistance of a given source of electricity. Thirdly, the sizes of nanoparticles absorbing ionizing gamma quanta are selected in such a way as to ensure the largest number of electrons emitted from them into the electrolyte per one absorbed gamma quantum.

The mechanical stability of the chains of nanoparticles is ensured by the fact that they are fixed on thin mechanically strong grids.

The electrical conductivity of the chains of nanoparticles is ensured either by the fact that the nanoparticles are made of metal, or by the fact that a thin layer of electrically conductive material is deposited on these chains before they are immersed in the electrolyte, providing, on the one hand, the electrical conductivity necessary for the charge to drain from the chain and, on the other hand side, creating, together with the electrolyte, an insulating layer in the form of a negative contact potential difference relative to it.

The electrolyte and the nets immersed in it with chains of nanoparticles are placed in containers with walls of light chemical elements that are transparent to ionizing gamma radiation, the device of which the device is intended to be converted into electricity. The operation scheme of the inventive device is shown in FIG. 3. The upper part of the figure shows two grids of electrically conductive materials. The left grid 1 with superlong nanochains 2 placed on it has a negative contact potential difference with respect to the electrolyte. The right grid 3, which is immersed in an electrolyte to collect electrons emitted into it from nanoparticles and transfer them to an external circuit, has a positive contact potential relative to the electrolyte.

The lower part of the figure shows a schematic diagram of the complete device. When it is irradiated with ionizing radiation 4, the flow of which is shown coming from above, the grids with chains of nanoparticles placed on them emit electrons into electrolyte 5 (placed in vessel 6) and charge positively. The grids collecting electrons emitted into the electrolyte are negatively charged. When the electrical leads from these grids are closed to an external load, 7 electrons from the collecting grids flow through the external circuit to the grids with the nanoparticles emitting them, doing useful work.

As confirmation of the implementation capabilities of the inventive device, Fig. 4 shows photographs of ultra-long chains formed from several spherical nanoparticles of molybdenum and lead oxides formed by several methods. Photographs were obtained using optical and scanning electron microscopy, a) A large-scale photograph of ultra-long molybdenum oxide nanochains with a 15-cm ruler; b) optical microscopy of one of such chains (horizontal frame size - 2 mm); c) scanning electron microscopy of a fragment of an extra-long molybdenum oxide nanochain (horizontal frame size - 150 microns); d) an enlarged electron microscopic image of the same nano chain of molybdenum oxide (horizontal frame size - 3 microns); e) an electron microscopic image of a fragment of a lead oxide nanochain (horizontal frame size - 50 microns); f) an enlarged electron microscopic image of the same lead oxide nanochain (horizontal frame size - 10 microns).

Claims (1)

A device for converting ionizing radiation into electricity, consisting of conductors with a small and large atomic number, separated by an insulator layer, characterized in that the role of a conductor with a large atomic number is played by continuous chains of nanoparticles with close to spherical geometries, and as a conductor with a light the atomic number is the liquid electrolyte, which creates an insulating double layer at the interface between the heavy and light conductors.

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