RU2658302C1 - Method of generating intense flows of charged carbon nanoparticles - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention relates to a method for generating intense flows of charged carbon nanoparticles. In the process, carbon nanoparticles are pre-charged to produce positively charged polyatomic carbon ions

, where N is the number of carbon atoms in the nanoparticle, Z is an integer electric charge of a nanoparticle. Charging is performed up to the specific charge Q/m, selected in the range from 5.3⋅10⁵ C/kg up to 1.1⋅10⁶ C/kg, where Q=Z⋅e, m is the mass of the nanoparticle, e is the elementary electric charge. Charged nanoparticles accelerate to achieve a speed of at least 10⁷ m/s at a specific kinetic energy per carbon atom E/N of not less than 8 MeV, where E is the kinetic energy of a charged nanoparticle. Acceleration of charged nanoparticles is carried out at a magnitude of the accelerating potential of the electric field of not less than 10⁸ V. Fullerenes or nanotubes are used as carbon nanoparticles. Acceleration of charged nanoparticles is carried out with the help of accelerators of charged particles of various types: linear accelerators, cyclic accelerators with linear accelerating sections, cyclotrons. At the input and output of the accelerator, longitudinal and transverse compression of the flow of charged nanoparticles is carried out using phase flow sealers. As longitudinal phase seals, accelerating interelectrode gaps along the direction of motion of charged nanoparticles are used, and magnetic lenses are used as transverse phase seals.

EFFECT: technical result is to provide conditions for achieving velocities of the order of 10⁷ m/s and charged-particle energies required for research related to the interaction of high-speed and high-energy flows of charged nanoparticles with each other and with the target material, in particular from the point of view of investigating the feasibility of performing thermonuclear fusion reactions.

7 cl

Description

The invention relates to methods for accelerating intense flows of charged particles, and more particularly to accelerating intense flows of charged carbon nanoparticles in an electric field to high energies sufficient to carry out fusion reactions and conduct studies at particle speeds comparable to the speed of light, in particular studies of the state of matter with extreme parameters.

At present, various methods for accelerating micro- and macroparticles, atomic ions and elementary particles (electrons, protons) have been developed and practically implemented. The highest values of power and intensity were achieved for ion beams in a pulsed mode. (Fortov V.E., Hoffmann D., Sharkov B.Yu. Intense ion beams for the generation of extreme states of matter // Uspekhi Fizicheskikh Nauk. February 2008, Volume 178, No. 2. P.113-138). It should be noted that atomic ions, although they can be accelerated to high speeds, have a significant limitation on the amount of energy per accelerated particle, due to their low mass.

When accelerating intense flows of charged particles, the following problems arise that are characteristic of all types of particles currently used. With an increase in the mass of the accelerated particle, its velocity, specific charge and specific energy fall. Therefore, it is practically impossible to accelerate a charged micro- or particulate to high speeds comparable to the speed of light.

The limiting values of the electric charge of a particle and the ratio of charge to mass of a particle are determined by the maximum value of the intrinsic electric field on its surface. This field is limited by field emission (with a negative particle charge) or field ion emission (with a positive particle charge), as well as the maximum allowable mechanical stresses in a particle arising from the action of Coulomb repulsive forces.

When charged particles are accelerated using a cyclotron, the maximum magnetic field limits the maximum particle mass, which is associated with the possibility of particle acceleration in a cyclotron with a calculated minimum particle orbit radius. This parameter determines the dimensions of the cyclotron as a whole.

The minimum transverse and longitudinal dimensions of the flow of accelerated particles are limited by the action of the Coulomb repulsion forces of particles, which significantly reduces the maximum achievable currents, flow intensity and energy density on the target in continuous and pulsed acceleration modes.

The above technical problems are characteristic of all known methods of acceleration of various types of charged particles. So, for example, in patent RU 2371891 C1 (published October 27, 2009) a method is described for accelerating microparticles to high speeds and energies using a linear accelerator. The known method is intended for modeling micrometeorite effects on spacecraft. The method includes the generation of charged solid particles by means of an injector and their acceleration in a linear accelerator, at the outlet of which are inductively arranged sensors and calibration sections, providing focusing of microparticles. At the exit from the accelerator, a charged microparticle acquires an energy of the order of 0.5 MeV. With an effective accelerating potential U = 700 kV, a particle size of ~ 25 μm and a specific particle charge Q / m (where Q = Z⋅e, m is the particle mass, e is the elementary electric charge, Z is the integer electric charge of the particle), which is 1 C / kg to 150 C / kg, the particle velocity reached V = 13 km / s (Linear accelerator for modeling micrometeorites / ND Semkin [et al.] // Instruments and experimental equipment. 2007. No. 2. P. 140-147).

Cyclic electrostatic and electrodynamic accelerators are also used to accelerate charged particles to high speeds and energies. Particles with a size of 0.1-10 μm are accelerated in the accelerator to a speed of V = 25 km / s with a total effective accelerating potential of U = 5 MB and a specific charge of particles Q / m = Z⋅e / m = 150 C / kg (A. Piyakov B. Cyclic accelerator of charged particles // Bulletin of the Samara Aerospace University. 2011. No. 7 (31). S. 36-40).

The limitation of the specific charge Q / m and velocity V for metal particles in the implementation of known methods of accelerating charged particles is due to the fact that the maximum value of the parameter Q / m is inversely proportional to the radius of the charged particle. Therefore, for particles having a sufficiently large size and, accordingly, a large mass, the parameter Q / m has a relatively small value. In addition, for metals, in comparison with carbon, the value of the limiting field of autoion emission, which limits the maximum particle charge, is significantly lower. In this case, it is impossible to increase the specific charge of the particle (Q / m) to values at which the required speeds and energies of accelerated charged particles are achieved. The known analogue methods are characterized by the limitation of the maximum values of particle velocities and energies: the particle velocity does not exceed 2.5 × 10 ⁴ m / s, and the maximum specific energy is 100 eV per atom of an accelerated charged particle. These restrictions are associated with relatively small values of the specific charge of the particles: Q / m≤1.5⋅10 ² C / kg.

, где N=60 - число атомов углерода в наночастице (фуллерене), Z=l, 2, 3 - целочисленные электрические заряды наночастиц (Особенности распыления кремниевых и углеродных мишеней ускоренными ионами фуллерена С₆₀ / М.В. Малеев [и др.] // Журнал физики и инженерии поверхности. 2015. №1. С. 91-95).The closest analogue of the invention is a method of creating flows of charged carbon nanoparticles, which are used as fullerenes. Intense flows of charged fullerenes are used to study the sputtering of silicon and carbon targets. The method includes charging carbon nanoparticles to obtain positively charged polyatomic ions

where N = 60 is the number of carbon atoms in a nanoparticle (fullerene), Z = l, 2, 3 are integer electric charges of nanoparticles (Features of sputtering of silicon and carbon targets by accelerated C ₆₀ fullerene ions / MV Maleev [et al.] // Journal of Physics and Surface Engineering. 2015. No. 1. P. 91-95).

. С помощью системы электростатических линз и диафрагм поток заряженных частиц фокусировался и ограничивался объем фазового пространства, занимаемый частицами. Затем заряженные частицы направлялись в магнитный сепаратор, в котором осуществлялось его пространственное разделение на пучки одно-, двух- и трехзарядных положительно заряженных наночастиц (многоатомных ионов). Заряженные наночастицы углерода ускорялись в электрическом поле до энергии в диапазоне от 2,5 до 24 кэВ при величине ускоряющего напряжения от 3 до 6 кВ.To implement the known method, carbon nanoparticles in the form of fullerenes obtained by the method of volume condensation in vacuum are used. The conversion of fullerenes into charged particles was carried out by ionization of the nanoparticles by electron impact before the formation of polyatomic ions

. Using a system of electrostatic lenses and diaphragms, the flow of charged particles was focused and the volume of phase space occupied by the particles was limited. Then the charged particles were sent to a magnetic separator, in which it was spatially separated into beams of single, double, and triple charged positively charged nanoparticles (polyatomic ions). Charged carbon nanoparticles were accelerated in an electric field to an energy in the range from 2.5 to 24 keV with an accelerating voltage of 3 to 6 kV.

The sufficiently low energy level of charged nanoparticles, achieved by the known method, is due to the technical problems that can be solved with its help, related to the study of the properties of sputtered silicon and carbon targets when exposed to intense flows of charged carbon nanoparticles and determination of the conditions for the formation of strong carbon films on the target surfaces with such exposure. It should be noted that the currently used research methods using flows of charged carbon nanoparticles cannot be used to solve problems associated with the implementation of fusion reactions and studies at particle speeds comparable to the speed of light. Among these problems are, in particular, the generation of extreme states of matter in the interaction of charged particle beams with matter, the study of the properties of matter at an ultrahigh energy concentration in the form of plasma clots with a temperature of the order of 10 keV and a density of the order of the density of the condensed state of the substance (10 ²² cm ^-3 )

To solve the stated problems, significantly higher energies are required (the specific kinetic energy per atom of an accelerated particle should be at least 8 MeV) and the velocity of charged particles (at least 10 ⁷ m / s). At the same time, it is necessary to establish the regimes of acceleration of carbon nanoparticles to extremely high velocities (not less than 10 ⁷ m / s), at which stability and integrity of accelerated nanoparticles would be ensured until they enter the interaction zone with the material under study or the collision zone of charged particle flows. In other words, it is necessary to ensure the estimated lifetime of charged particles when they are accelerated in an electric field with a potential value of at least 10 ⁸ V.

To accelerate intense flows of charged particles to the required level of speeds and energies, along with the above requirements, it is necessary to ensure a high specific charge of the accelerated charged particle: the ratio Q / m should be at least 5.3 не10 ⁵ C / kg. So, for example, for metal microparticles with a characteristic size of ~ 1 μm, the maximum values of the specific charge do not exceed 10 ³ C / kg. The specific charge for each type of particle is limited by the limiting values at which the destruction of the particle occurs due to the action of autoionic emission from the surface of the particles (for positively charged particles) and electrostatic repulsive forces acting inside the particle.

The invention is aimed at eliminating problems by selecting acceleration modes in the electric field of intense flows of charged carbon nanoparticles and the electric charge of the nanoparticles before their acceleration. The technical result achieved is to provide conditions for increasing the speeds and energies of charged particles to values at which thermonuclear fusion reactions and research can be carried out when high-speed high-energy flows of charged particles interact with each other and with the material under study. Moreover, due to the use of charged carbon nanoparticles as accelerated particles, the possibility of obtaining the maximum energy per accelerated particle is fully realized.

) и нанотрубок. Наночастицы углерода могут быть объединены в кластеры (группы заряженных частиц), при ускорении в электрическом поле.The achievement of the technical result is ensured by the implementation of the method of creating intense flows of charged carbon nanoparticles. A characteristic feature of this method is the use of carbon nanoparticles with calculated specific charge values as accelerated charged particles. Carbon nanoparticles can mainly be used in the form of fullerenes (polyatomic ions

) and nanotubes. Carbon nanoparticles can be combined into clusters (groups of charged particles), when accelerated in an electric field.

Fullerenes can be obtained by various methods, including by burning graphite electrodes in an electric arc discharge in a helium atmosphere at low pressures (Solid C ₆₀ : a New Form of Carbon / W. Kraetschmer [et al.] // Nature. 1990, V 347. P. 354-358). At present, optimum parameters for the evaporation of graphite electrodes, including pressure, atmospheric composition, current, and electrode diameter, have been selected at which the highest fullerene yield is achieved, which is on average 3-12% of the mass of the products obtained (Fullerenes Synthesis in Combustion / Howard JB [et. al.] // J. Carbon. 1992. V. 30, No. 8. P. 1183-1201).

. Протяженные цилиндрические структуры (углеродные нанотрубки) образуются вместе с фуллеренами при электродуговом испарении графитовых электродов. Наиболее эффективным методом получения углеродных нанотрубок в настоящее время является низкотемпературный метод, заключающийся в каталитическом пиролизе углеводородов (Catalytic production and purification of nanotubules having fullerene-scale diameters / V. Ivanov [et al.] // J. Carbon. 1995. V. 33, №12, P. 1727-1738).Single-walled carbon nanotubes are sheets of graphene (monolayers with the structure of a graphite plane) rolled into cylinders. Similar structures are stable with a cylinder diameter of 5-20

. Extended cylindrical structures (carbon nanotubes) are formed together with fullerenes during electric arc evaporation of graphite electrodes. The most effective method for producing carbon nanotubes at present is the low-temperature method, which consists in catalytic pyrolysis of hydrocarbons (Catalytic production and purification of nanotubules having fullerene-scale diameters / V. Ivanov [et al.] // J. Carbon. 1995. V. 33 No. 12, P. 1727-1738).

, где N - число атомов углерода в наночастице, Z - целочисленный электрический заряд наночастицы. Согласно изобретению наночастицы заряжают до величины удельного заряда Q/m, выбираемой в диапазоне от 5,3⋅10⁵ Кл/кг до 1,1⋅10⁶ Кл/кг, где m - масса наночастицы, е - элементарный электрический заряд. Заряженные наночастицы ускоряют в электрическом поле до достижения скорости не менее 10⁷ м/с при удельной кинетической энергии на атом углерода E/N не менее 8 МэВ, где Е - кинетическая энергия заряженной наночастицы.The method includes charging carbon nanoparticles to obtain positively charged polyatomic carbon ions

where N is the number of carbon atoms in the nanoparticle, Z is the integer electric charge of the nanoparticle. According to the invention, the nanoparticles are charged to a specific charge Q / m, selected in the range from 5.3 × 10 ⁵ C / kg to 1.1 × 10 ⁶ C / kg, where m is the mass of the nanoparticle, e is the elementary electric charge. Charged nanoparticles are accelerated in an electric field to a speed of at least 10 ⁷ m / s at a specific kinetic energy per carbon atom E / N of at least 8 MeV, where E is the kinetic energy of a charged nanoparticle.

, то указанная характеристика способа соответствует следующему условию выбора целочисленного заряда Z наночастицы (положительного иона фуллерена): 4≤Z≤10. За пределами расчетного диапазона значений удельного заряда наночастиц углерода невозможно достижение технического результата, с одной стороны, из-за разрушения частиц до момента входа в область взаимодействия (с другими частицами либо с материалом мишени), а с другой - вследствие недостаточной скорости и энергии заряженных частиц, ускоренных в электрическом поле.An essential characteristic of the method is the charging of carbon nanoparticles to a specific charge in the calculated range of values, the lower limit of which (5.3⋅10 ⁵ C / kg) determines the condition for achieving the required level of energies and velocities of charged particles, and the upper limit (1.1⋅10 ⁶ C / kg) is a condition for maintaining the stability and integrity of charged nanoparticles under the action of electrostatic repulsive forces and autoionic emission. For example, if polyatomic fullerene ions are used as charged carbon nanoparticles

, then this characteristic of the method corresponds to the following condition for choosing an integer charge Z of a nanoparticle (positive fullerene ion): 4≤Z≤10. Outside the calculated range of the specific charge of carbon nanoparticles, it is impossible to achieve a technical result, on the one hand, due to the destruction of particles before entering the interaction region (with other particles or with the target material), and on the other, due to insufficient speed and energy of charged particles accelerated in an electric field.

, заряженных до величины Ze=+10e, при ускоряющем потенциале электрического поля 10⁸ В скорость частиц может достигать 1,6⋅10⁷ м/с. Для микрочастиц с характерным размером ~1 мкм теоретическая предельная скорость при таком же ускоряющем потенциале составляет всего лишь 10⁵ м/с.The fulfillment of this essential condition is ensured by the special properties of carbon nanoparticles: in comparison with other materials, carbon nanoparticles have higher strength properties and higher limit values of the electric field strength at which autoionic emission from the particle surface occurs. When using these properties of carbon nanoparticles, the condition for choosing their specific charge is a criterion for achieving high speeds and energies of accelerated particles, which is necessary for solving problems in the field of controlled thermonuclear fusion and studying the interaction of accelerated particles with each other and with the target material. For example, when using fullerene ions as charged carbon nanoparticles

charged to Ze = + 10e, with an accelerating electric field potential of 10 ⁸ V, the particle velocity can reach 1.6 достиг10 ⁷ m / s. For microparticles with a characteristic size of ~ 1 μm, the theoretical limiting velocity at the same accelerating potential is only 10 ⁵ m / s.

The maximum energy flux density G for nonrelativistic flows of charged particles is proportional to the square root of the ratio of charge to mass (specific charge): G∝ (Q / m) ^1/2 . Therefore, obtaining a high energy flux G for charged carbon nanoparticles is associated with ensuring the maximum value of the ratio of charge to mass of the particle. In the case of using charged carbon nanoparticles, including fullerenes and nanotubes, which have higher specific charge values in comparison with micro- and macroparticles, the maximum values of the energy flux density G can be achieved.

The acceleration of charged nanoparticles to a predetermined level of velocity and energy (the velocity should be at least 10 ⁷ m / s, and the specific kinetic energy per carbon atom E / N - at least 8 MeV) is carried out at an accelerating potential of the electric field of at least 10 ⁸ V. Charged nanoparticles can be accelerated in an electric field using a linear accelerator, a cyclic accelerator with linear accelerating sections, or a cyclotron. In a classical cyclotron, charged nanoparticles are accelerated in an electric field between the dees in the region of a constant magnetic field.

When using a cyclotron, charged nanoparticles can be pre-accelerated and sent to the acceleration path using an injector made in the form of a linear accelerator. For longitudinal compression of the generated stream of charged particles, i.e. To reduce the volume of the phase space occupied by the particles, two phase compactors of the charged nanoparticle flow can be used, which are made in the form of accelerating interelectrode gaps (gaps) located along the direction of motion of the nanoparticles. These devices act as groupers of charged particles in the longitudinal direction. The first interelectrode gap (longitudinal phase sealer) is placed at the entrance to the accelerator, and the second at the exit of the accelerator.

At the inlet and outlet of the accelerator can also be transverse compression of the flow using two phase compressors of the flow of charged carbon nanoparticles, made in the form of magnetic lenses. These devices are used as groupers of charged particles in the transverse direction (along the cross section of the stream). The first magnetic lens (transverse phase seal) is placed at the entrance to the accelerator, and the second is at the exit of the accelerator.

It should be noted that the maximum current of charged particles is directly proportional to the ratio of the particle charge to its mass. High values of the accelerated nanoparticle flux parameters (current up to 200 mA, intensity up to 20 MW, energy per carbon atom up to 10 ⁸ eV, energy per carbon nanoparticle up to 7⋅10 ¹⁴ eV) can be obtained by accelerating nanoparticles using a classical cyclotron. When accelerating carbon nanotubes in an electric field using linear accelerators in a pulsed mode, the limiting currents and the intensity of the accelerated flow of nanoparticles increase significantly: the current value is up to 1000 A, the intensity is up to 100 GW.

Consider the basic conditions under which it is possible to implement a method of creating intense flows of charged carbon nanoparticles and ensure the achievement of a technical result.

The maximum specific charge of a positively charged carbon nanoparticle is associated with the limiting value of the electric field on its surface, at which the particle is destroyed due to autoionic emission and the action of repulsive Coulomb forces.

, при котором наступает автоионная эмиссия - испускание ионов с поверхности частицы под действием электрического поля (испарение вещества). Величина поля автоионной эмиссии примерно на порядок больше значения поля автоэлектронной эмиссии и составляет для углерода

МВ/см при температуре вблизи абсолютного нуля. Следует отметить, что величина напряженности поля автоионной эмиссии для углерода существенно выше по сравнению с соответствующими предельными значениями для металлов. Так, например,

для вольфрама составляет 1052 МВ/см, а для титана - 399 МВ/см.The electric field strength Es on the particle surface is limited by

at which autoionic emission occurs - the emission of ions from the surface of a particle under the influence of an electric field (evaporation of a substance). The field of field emission is approximately an order of magnitude larger than the field of field emission and is for carbon

MV / cm at a temperature near absolute zero. It should be noted that the magnitude of the field of autoion emission for carbon is significantly higher compared with the corresponding limit values for metals. For example,

for tungsten is 1052 MV / cm, and for titanium - 399 MV / cm.

В/м для сферической наночастицы - фуллерена можно определить предельный заряд Q, при котором начинается автоионная эмиссия:Based on the threshold value of the field of field emission

V / m for a spherical nanoparticle - fullerene, it is possible to determine the limiting charge Q, at which autoion emission begins:

Q = Ze = ε ₀ E _s ⋅4πr ² ≈1.9⋅10 ^-18 Cl≈12е, Z = + 12,

where ε ₀ ≈ 8.85⋅10 ^-12 F / m is the dielectric constant of vacuum; r = 0.35⋅10 ^-9 m is the radius of fullerene C ₆₀ ; е≅1.6⋅10 ^-19 Кл - elementary electric charge.

составляет:Thus, the limiting value of the electric field of autoion emission for fullerenes corresponds to the maximum charge of a carbon nanoparticle Z = + 12. Therefore, the limit value of the specific charge of fullerene

is:

For a spherical carbon nanoparticle of arbitrary radius, the dependence determining the specific charge has the following form:

where ρ is the density of the substance of the particle.

It can be seen from the above dependence (1) that for microparticles having a larger size (radius) compared to fullerene, the restriction on autoionic emission will lead to a decrease in the maximum specific charge, since Q / m is inversely proportional to the particle radius.

For the cylindrical geometry of carbon nanoparticles characteristic of nanotubes, the Q / m (r) dependence takes the following form:

From a comparison of dependences (1) and (2), it follows that the maximum specific charge for nanotubes is 1.5 times lower compared to spherical carbon nanoparticles (fullerenes): Q / m = 1.1⋅10 ⁶ C / kg.

The second condition, limiting the maximum electric field on the surface of the nanoparticle, is associated with the Coulomb repulsion of charges and is determined by the strength properties of the particle material. The estimation of the value of mechanical stresses in a nanoparticle is based on the solution of a system of elasticity equations in spherical geometry. The maximum value of the azimuthal stress component σ _ϕ on the surface of the sphere bounding the surface of the nanoparticle, taking into account the connection of the electric field E _s on the surface of the particle with its charge in accordance with the Gauss theorem, is determined based on the following relationship:

where q is the volumetric charge density of the particle, C / m ³ ; r is the particle radius; ν is the Poisson's ratio.

To ensure the integrity of the accelerated carbon nanoparticles, the value of σ _ϕ should not exceed the value of the mechanical stress σ _B corresponding to the tensile strength of the particle material. This condition determines the following dependence for the maximum value of the field on the particle surface:

В/м. Данная величина примерно в 1,5 раза больше максимального предельного значения напряженности электрического поля, при котором возникает автоионная эмиссия с поверхности фуллерена.When the characteristic value of Poisson's ratio and the value of the limit ν≈0.3 carbon strength σ _B ≈150 GPa can be determined according to the relationship (4), the magnitude of the maximum electric field intensity:

V / m This value is approximately 1.5 times greater than the maximum limit value of the electric field strength at which autoionic emission from the fullerene surface occurs.

For the cylindrical geometry of nanotubes, the maximum electric field on the surface of the nanoparticle, associated with the Coulomb repulsion of charges, is calculated according to the following dependence:

В/м. Следовательно, нанотрубки по сравнению с фуллеренами имеют более высокое пороговое значение электрического поля, при котором происходит разрушение частиц.The value calculated according to dependence (5) is greater than the maximum field for the spherical geometry of nanoparticles. The limiting value of the electric field for nanotubes is

V / m Therefore, nanotubes in comparison with fullerenes have a higher threshold value of the electric field at which the destruction of particles occurs.

Thus, the limiting values of the electric field, which are the criteria for the non-destruction of nanoparticles by the strength factor and the possibility of autoion emission, approximately coincide. For various types of carbon nanoparticles, the upper limit of the specific charge of nanoparticles, at which they are not destroyed as a result of the Coulomb repulsive forces and autoionic emission, is Q / m≈1.1⋅10 ⁶ C / kg.

The lower limit value of the specific charge of carbon nanoparticles is selected based on the condition of the possibility of generating high-energy and high-speed intense flows of charged carbon nanoparticles, which can be used to carry out fusion reactions and conduct studies at particle speeds comparable to the speed of light. To achieve these goals, the particle velocity should be at least 10 ⁷ m / s, and the corresponding value of the specific kinetic energy of charged particles per carbon atom E / N - at least 8 MeV. These conditions are realized when the specific charge of carbon nanoparticles is not less than 5.3⋅10 ⁵ C / kg. The calculated flow parameters of charged carbon nanoparticles can be achieved by accelerating in an electric field with an accelerating potential of at least 10 ⁸ V. With the specified lower limit on the specific charge of carbon nanoparticles, the minimum integer fullerene charge should be at least Z = + 4. It should be noted that when using particles with a size of ~ 1 μm or more, for which the parameter Q / m does not exceed 10 ³ C / kg, the required minimum values of the parameters of the accelerated flow of charged particles cannot be achieved.

The invention is further illustrated by the description of specific examples of the method for creating intense flows of charged carbon nanoparticles.

с положительным зарядом до Z=+6 при удельном заряде Q/m=0,8⋅10⁶ Кл/кг (Senn G., Mark Т. D., Scheier P. Charge Separation Processes of Highly Charged Fullerene Ions // J. Chem. Phys. 1998. Vol. 108, №3). Поток фуллеренов формируется при нагреве фуллереновой пудры в печи при температуре до 1020 К. На поток фуллеренов воздействуют пучком электронов с током до 2 мА. В результате воздействия электронов происходит многократная ионизация наночастиц углерода. Образованные заряженные наночастицы вытягиваются из области взаимодействия электрическим полем, направление которого перпендикулярно направлениям электронного пучка и исходного пучка нейтральных фуллеренов.The necessary charge of carbon nanoparticles, in particular fullerene, is provided by ionizing the generated nanoparticle stream by an electron beam. As a result, charged polyatomic ions are formed.

with a positive charge up to Z = + 6 with a specific charge Q / m = 0.8⋅10 ⁶ C / kg (Senn G., Mark T. D., Scheier P. Charge Separation Processes of Highly Charged Fullerene Ions // J. Chem. Phys. 1998. Vol. 108, No. 3). The fullerene stream is formed when the fullerene powder is heated in a furnace at a temperature of up to 1020 K. The electron beam is affected by an electron beam with a current of up to 2 mA. As a result of the action of electrons, multiple ionization of carbon nanoparticles occurs. The formed charged nanoparticles are pulled out of the interaction region by an electric field whose direction is perpendicular to the directions of the electron beam and the initial beam of neutral fullerenes.

,

,

и т.д. Для отбора наночастиц, электрический заряд которых соответствует условию выбора удельного заряда Q/m (от 5,3⋅10⁵ Кл/кг до 1,1⋅10⁶ Кл/кг), перед входом в ускоритель производится сепарация заряженных наночастиц по величине заряда. Для этого может использоваться магнитный сепаратор, с помощью которого поток заряженных наночастиц (многоатомных ионов) пространственно разделяется при движении в области действия магнитного поля сепаратора на отдельные пучки, имеющие различные положительные заряды. Выделенный поток наночастиц, имеющих необходимый заряд, направляется в ускоритель заряженных частиц.In the process of charging carbon nanoparticles, polyatomic ions with different charges Z are formed, for example, fullerenes:

,

,

etc. To select nanoparticles whose electric charge corresponds to the condition for the choice of specific charge Q / m (from 5.3 × 10 ⁵ C / kg to 1.1 × 10 ⁶ C / kg), charged nanoparticles are separated by the amount of charge before entering the accelerator. For this, a magnetic separator can be used, with the help of which the flow of charged nanoparticles (polyatomic ions) is spatially separated when moving in the field of action of the magnetic field of the separator into individual beams having different positive charges. The selected stream of nanoparticles having the necessary charge is directed to the charged particle accelerator.

) могут быть получены при облучении сформированного потока фуллеренов мощным лазерным импульсом в инфракрасном диапазоне. Мощность импульсов составляет 10¹⁵ Вт при длительности импульсов 7⋅10^-14 с (Bhardwaj V. R., Corkum Р. В., Rayner D.M. Internal Laser-Induced Dipole Force at Work in С₆₀ Molecule // Physical Review Letters. 2003. V. 91, №20).Higher values of the charge of carbon nanoparticles (polyatomic ions

) can be obtained by irradiating the formed stream of fullerenes with a powerful laser pulse in the infrared range. The pulse power is 10 ¹⁵ W with a pulse duration of 7⋅10 ^-14 s (Bhardwaj VR, Corkum R.V., Rayner DM Internal Laser-Induced Dipole Force at Work in C ₆₀ Molecule // Physical Review Letters. 2003. V. 91 , No. 20).

Carbon nanoparticles can also be charged by contact with an electrode (anode), proton beam irradiation, ionization during electron-cyclotron resonance (Wethekam S., Winter H. Elasticity, Internal Excitation, and Charge Transfer during Grazing Scattering of keV Fullerenes from a LiF ( 100) Surface // Nuclear Instruments and Methods in Physics Research. 269. 2011. P. 1179-1184).

являются стабильными, время их жизни составляет не менее одной секунды. Стабильность и достаточно большое время жизни наночастиц, необходимое для их ускорения и транспортировки в область воздействия на другие частицы или материалы, обеспечивается за счет ограничения величины их удельного заряда Q/m в пределах расчетного диапазона: от 5,3⋅10⁵ Кл/кг до 1,1⋅10⁶ Кл/кг.The resulting polyatomic ions

are stable, their life time is at least one second. The stability and sufficiently long lifetime of nanoparticles necessary for their acceleration and transportation to the area of influence on other particles or materials is ensured by limiting the value of their specific charge Q / m within the calculated range: from 5.3 от10 ⁵ C / kg to 1.1⋅10 ⁶ C / kg.

The generated intense flow of charged nanoparticles, the charge of which satisfies the condition for the choice of specific charge, is directed to the input of the charged particle accelerator, with the help of which the particles are accelerated in the electric field to the required velocity level (at least 10 ⁷ m / s) and specific kinetic energy (at least 8 MeV per carbon atom).

To accelerate charged carbon nanoparticles, a linear resonant accelerator can be used in which positively charged particles are accelerated by an electric field in the gaps between cylindrical drift tubes (see, for example, international application WO 2007/144058 A1, published on December 21, 2007). In this example, the potential difference between the drift tubes for each accelerating gap is 500 kV. The frequency of the accelerating field ƒ is from 1000 MHz to 3000 MHz. The kinetic energy of 500 MeV per fullerene and the specific kinetic energy of 8.4 MeV per carbon atom are achieved using a linear accelerator containing 1000 accelerating gaps.

The acceleration of charged nanoparticles in an electric field can be carried out cyclically using a cyclic accelerator with linear accelerating sections. Changing the direction of motion of charged particles to enter them into a given closed path of motion is carried out using accelerators, and changing the direction of motion of charged particles to deflect them from the path of motion, in particular to remove them from orbit, using accelerators. Charged particles in such accelerators move along closed paths consisting of linear sections (linear accelerating sections), between which are guiding devices that change the particle path (see, for example, patent RU 2456781 C1, published July 20, 2012). The input and output of particles from the accelerator path of the accelerator is provided with the help of special devices that provide deviation of the particle path. The accelerator contains cylindrical electrodes alternately connected to two outputs of a high voltage source. After reaching the set speed, the voltage in one of the guiding devices is turned off, and the flow of charged nanoparticles is removed from the accelerator.

с линейной скоростью 1,6⋅10⁷ м/с величина индукции постоянного магнитного поля вычисляется согласно зависимости: В [Тл]=18/R [м], где R - радиус орбиты вращения иона. При радиусе орбиты R=3 м индукция магнитного поля должна быть равна 6 Тл. При данной величине магнитного поля период обращения фуллерена в циклотроне составит 3.6⋅10^-6 с. Для достижения скорости 1,6⋅10⁷ м/с и энергии 1,0 ГэВ при амплитуде напряжения между дуантами ускорителя 10⁵ В заряженная наночастица углерода должна совершить 10⁴ оборотов. За счет увеличения эффективной длины разгона наночастицы, при сохранении компактности устройства, ускорение наночастиц углерода с помощью циклотрона является наиболее целесообразным способом ускорения.In another embodiment, charged carbon nanoparticles can be accelerated in an electric field using a cyclotron. In the classical cyclotron (Laurence accelerator), charged particles are accelerated by an electric field acting in the gaps between the dees. The movement of charged particles along a spiral trajectory is provided using a constant magnetic field (see, for example, patent RU 2373673 C1, published on November 20, 2009). During acceleration in such accelerators, the centrifugal force acting on the particle is balanced by the force arising from the action of a magnetic field directed perpendicular to the direction of motion of the charged particle. When moving a polyatomic ion

with a linear velocity of 1.6⋅10 ⁷ m / s, the magnitude of the induction of a constant magnetic field is calculated according to the dependence: V [T] = 18 / R [m], where R is the radius of the orbit of rotation of the ion. When the radius of the orbit R = 3 m, the induction of the magnetic field should be equal to 6 T. At a given magnitude of the magnetic field, the period of revolution of the fullerene in the cyclotron will be 3.6⋅10 ^-6 s. In order to achieve a speed of 1.6 710 ⁷ m / s and an energy of 1.0 GeV with a voltage amplitude between the accelerators of 10 ⁵ V, a charged carbon nanoparticle must complete 10 ⁴ revolutions. By increasing the effective length of the acceleration of the nanoparticles, while maintaining the compactness of the device, the acceleration of carbon nanoparticles using a cyclotron is the most appropriate way to accelerate.

A charged particle injector made in the form of a linear accelerator is used to introduce charged nanoparticles into the accelerating path of the cyclotron. The injector is installed at a calculated distance from the axis of the cyclotron. Rotating in a magnetic field around the axis of the cyclotron, charged nanoparticles are accelerated in one rotation period in two gaps formed between the dees, between which an alternating electric field is applied with a frequency corresponding to the particle rotation frequency. The withdrawal of charged nanoparticles from the accelerator path is carried out through a channel (deflector) located at a distance of radius R from the axis of rotation. Charged nanoparticles are removed from the accelerator by exposure to them by an electric field that deflects their trajectory along the tangent to the spiral trajectory of rotation in the cyclotron.

(Behavior of Space Charge Dominated Beam in High-Current Compact Cyclotron / A.Goswami [et al.] // Nuclear Instruments and Methods in Physics Research A. 2006. V. 562. P. 34-40).The limiting flux density of charged particles is determined by the transverse and longitudinal Coulomb repulsion of particles. The ratio of the beam current to the limiting current characterizes the divergence of the beam of charged particles due to the action of Coulomb repulsive forces. An important parameter that determines the density of the flow of charged particles is emittance - a numerical characteristic of the accelerated flow of charged particles equal to the volume of the phase space occupied by the particles. Distinguish between longitudinal and transverse emittance. In the case of transverse emittance, one usually goes from considering particles in the space of coordinates and momenta to considering particles in the space of coordinates and angles of directions of motion. The characteristic values of the transverse emittance for the proton flux accelerated by the cyclotron are

(Behavior of Space Charge Dominated Beam in High-Current Compact Cyclotron / A. Goswami [et al.] // Nuclear Instruments and Methods in Physics Research A. 2006. V. 562. P. 34-40).

Longitudinal and transverse compression of the flow of charged carbon nanoparticles ensures maximum density and maximum current of accelerated nanoparticles by reducing the volume of phase space occupied by the particles. To compress the flow, longitudinal and transverse phase compressors of the flow of charged carbon nanoparticles are used.

Longitudinal compression of the flow of charged nanoparticles is carried out at the inlet and outlet of the charged particle accelerator using two phase seals made in the form of accelerating interelectrode gaps (gaps) located along the direction of motion of the nanoparticles and acting as electrostatic lenses. The first accelerating interelectrode gap is placed at the entrance to the accelerator, and the second at the exit of the accelerator. In the case of using an injector in a cyclotron, the first interelectrode gap is placed in front of the injector. The electric field in the accelerating gaps of the accelerators changes, for example, according to a sinusoidal law. By modulating the particle velocity along the longitudinal coordinate, an additional increase in the flux density of charged particles is provided (Sing Babu P., Goswami A., Pandit VS Simulation of Beam Bunching in the Presence of Space Charge Effects // Nuclear Instruments and Methods in Physics Research A. 2009 V. 603. P. 222-227).

Through the use of longitudinal phase seals in the form of additional accelerating interelectrode gaps in cyclic or linear accelerators, longitudinal compression of the flow of charged particles (reduction of the phase space occupied by the particles in the longitudinal direction) is achieved at the input from the accelerator up to 20 times, and at the output, two times.

At the inlet and outlet of the accelerator, the flow of charged nanoparticles is also transversely compressed using two phase compressors of the flow of charged carbon nanoparticles, made in the form of magnetic lenses. The first magnetic lens is placed at the entrance to the accelerator, and the second at the output of the accelerator. Transverse compression of the particle flow occurs due to the azimuthal profiling of the magnetic field created by magnetic lenses. As a result of transverse compression of the flow, the maximum steady-state fullerene current in the transversely compressed flow will be I ~ 200 mA, and the fullerene flux density will be 1.3 --10 ¹⁷ particles / s. With these parameters, the following energy characteristics can be obtained for the fullerene flux: energy flux — H≈20 MW, energy flux density at a diameter of the cross section of the particle flux (spot diameter) 6 mm — G≈80 MW / cm ² .

In the case of using nanotubes as carbon nanoparticles, the following flow characteristics of charged carbon nanoparticles can be obtained.

=10^-2 м, удельный заряд Q/m=10⁶ Кл/кг. При ускоряющем потенциале ϕ=10⁸ В углеродная нанотрубка может быть ускорена до скорости V=1,6⋅10⁷ м/с и энергии Т=7⋅10¹⁵ эВ. Длительность импульсного воздействия ускоренных нанотрубок на мишень будет составлять ~10^-9 с. Ток, создаваемый движущейся нанотрубкой, будет равен:

мА. При параллельном движении десяти нанотрубок величина тока будет составлять 180 мА. Данная величина сравнима с максимально достижимым током, полученным для потока фуллеренов с учетом его поперечного сжатия с помощью магнитных линз. Поток энергии в этом случае (для десяти углеродных нанотрубок) составит H≈18 МВт.Consider the flow of nanotubes accelerated in an electric field. Nanotubes can be single-walled or multi-walled. The length of various types of nanotubes can vary in a wide range: from 10 ^-8 m to 10 ^-2 m. For evaluative calculations, we choose a nanotube with the following characteristic parameters: radius r = 3.5 × ^{10 -10} m, length

= 10 ^-2 m, specific charge Q / m = 10 ⁶ C / kg. At an accelerating potential ϕ = 10 ⁸ V, a carbon nanotube can be accelerated to a speed of V = 1.6 × 10 ⁷ m / s and energy T = 7 × 10 ¹⁵ eV. The duration of the pulse action of accelerated nanotubes on the target will be ~ 10 ^-9 s. The current generated by a moving nanotube will be equal to:

ma With the parallel movement of ten nanotubes, the current value will be 180 mA. This value is comparable to the maximum achievable current obtained for the fullerene flux taking into account its transverse compression using magnetic lenses. The energy flow in this case (for ten carbon nanotubes) will be H≈18 MW.

Considering that elementary charges in nanotubes are held by strong bonds of interatomic interaction, higher limit values of current and energy flux can be achieved for carbon nanotube flows. The difference between the fullerene flux and the nanotube flux is that the nanotube flux can consist of a small number of single nanotubes, providing currents comparable to the limiting values for the fullerene flux. The limiting value of the current of parallel moving carbon nanotubes can be estimated on the basis of the following boundary conditions: the potential energy of the particle at the flow boundary is equal to the energy of the particle along the flow axis, when moving along the flow axis a distance of the order of the radius of the flow, it will acquire a lateral velocity (expansion velocity) of the order of velocity along the flow axis. Under these conditions, the directed flow of charged particles should scatter to the sides at a distance along the flow axis of the order of the radius of the flow. In this case, the limiting current value for parallel moving carbon nanotubes will be I≈2⋅10 ⁴ A.

Evaluation of the radial expansion of the flow of charged carbon nanoparticles can be carried out by the magnitude of the radial electric field at the periphery of the flow of accelerated particles, which affects the expansion of the flow and limits the magnitude of the beam current. At the maximum steady-state current I ~ 200 mA of the flow of charged fullerenes and the diameter of the cross section of the flow d = 6 mm, the radial component of the electric field at the periphery of the flow will be E _R ≈7.7⋅10 ⁴ V / m. This value of the electric field strength is significantly less than the limiting value of the electric field strength at which autoion emission occurs. Thus, we can assume that the limiting current values of the accelerated beam of charged carbon nanoparticles are practically not affected by restrictions directly related to the properties of accelerated charged particles.

The radial component of the electric field created by one nanotube, the specific charge of which is Q / m≈10 ⁶ C / kg, at the periphery of the flow (r≈3⋅10 ^-3 m) is E _R ≈4.3⋅10 ³ V / m. The limit value of the current generated by nanotubes in parallel motion will be reached if the number of nanotubes in the flow reaches about 30. The value of the radial electric field in the flow of nanotubes can be reduced by reducing the length of the carbon nanotubes relative to the diameter of the flow. As a result, the limiting current for nanotubes can be I≈10 A with a flow diameter of about 6 mm.

The above experimental and calculated data confirms the possibility of creating intense flows of charged carbon nanoparticles moving at a speed of at least 10 ⁷ m / s with a specific kinetic energy per carbon atom E / N of at least 8 MeV. The indicated flow parameters of charged carbon nanoparticles are achieved as a result of their acceleration in an electric field. Carbon nanoparticles can be accelerated in an electric field in the form of a bunch of charged particles. By choosing the specific charge Q / m of carbon nanoparticles within the calculated range of values, stability and integrity of the nanoparticles during their acceleration in an electric field is ensured until they enter the reaction zone. Such a zone may be a zone of interaction with the test substance or a zone of collision of charged particles (during the implementation of fusion reactions).

The method of creating intense flows of charged carbon nanoparticles can be used to solve a number of technical and research problems, including:

- creating conditions for the occurrence of controlled thermonuclear fusion reactions, including those with inertial confinement;

- study of the properties of a substance at extreme parameters as a result of the interaction of intense flows of charged carbon nanoparticles with the target material;

- obtaining and studying the properties of a substance at an ultrahigh energy concentration in the form of a hot plasma with a temperature of the order of 10 keV and a density of the order of the density of the condensed substance (10 ²² cm ^-3 ).

Claims (7)

1. A method of creating intense flows of charged carbon nanoparticles, comprising charging carbon nanoparticles to obtain positively charged polyatomic carbon ions

where N is the number of carbon atoms in the nanoparticle, Z is the integer electric charge of the nanoparticle, and the acceleration of charged nanoparticles in an electric field, characterized in that the nanoparticles are charged to a specific charge Q / m, selected in the range from 5.3⋅10 ⁵ C / kg to 1.1⋅10 ⁶ C / kg, where Q = Z⋅е, m is the mass of the nanoparticle, e is the elementary electric charge, while the charged nanoparticles are accelerated in an electric field with an accelerating potential of at least 10 ⁸ V until the speed is reached not less than 10 ⁷ m / s and specific kinetic energy per carbon atom Yes E / N not less than 8 MeV, where E is the kinetic energy of a charged nanoparticle. 2. The method according to p. 1, characterized in that fullerenes or nanotubes are used as carbon nanoparticles. 3. The method according to p. 1, characterized in that the charged carbon nanoparticles are accelerated using a linear accelerator. 4. The method according to p. 1, characterized in that the charged carbon nanoparticles are accelerated using a cyclic accelerator with linear accelerating sections. 5. The method according to p. 1, characterized in that the charged carbon nanoparticles are accelerated using a cyclotron. 6. The method according to any one of paragraphs. 3-5, characterized in that the inlet and outlet of the accelerator carry out longitudinal compression of the flow using two phase compressors of the flow of charged carbon nanoparticles, made in the form of accelerating interelectrode spaces located along the direction of motion of the charged carbon nanoparticles, the first of which is placed at the entrance to the accelerator and the second at the output of the accelerator. 7. The method according to any one of paragraphs. 3-5, characterized in that at the inlet and outlet of the accelerator, the stream is transversely compressed using two phase flow compactors of charged carbon nanoparticles made in the form of magnetic lenses, the first of which is placed at the entrance to the accelerator, and the second at the exit of the accelerator.