RU2559288C1 - Method of accumulation of energy of flow of charged particles - Google Patents

Abstract

FIELD: power industry.

SUBSTANCE: method is implemented by execution in time of the following sequence of processes: generation of flow of charged particles, acceleration, focusing, deceleration and defocusing, and processes in the following sequence are performed periodically with the frequency of change of magnetic field value, and output of the flow of particles to the target occurs due to change of magnetic field induction on the stationary trajectory towards increase or decrease. All listed processes are performed under the influence of the same variable axially symmetric magnetic field of betatron type the parameters of which allow to conduct processes in the agreed mode and are determined as follows: the magnetic field induction in the are of stationary trajectory decreases proportionally to the distance ρ from the symmetry axis according to the law B ~ ρ^-α, where α = 0,5, the magnetic field induction B₀ on the stationary trajectory, circle with the radius ρ₀, amounts a half of the average value of magnetic field B_av inside this circle B₀ = 0,5·B_av; the frequency of change B₀, depending on the type of accelerated particles - electrons or ions, amounts ν = 10⁵-10⁹; change of B₀ in time is subject to the condition of frequency of B(t+2T) = B(t), B (t+T) = -B(t), where T = ν^-1 - a half-cycle of change of the value of magnetic field induction.

EFFECT: increase of density of energy of flow of charged particles.

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Description

The invention relates to the field of energy, and in particular to a technology for producing high-energy charged particles, and is intended for use in the field of nuclear physics and technology.

к источнику. Основным недостатком указанной технологии является непрерывность процесса движения и фокусировки электронов, что не позволяет использовать ее для аккумуляции энергии потока.As an analogue of the proposed method used the technology of precision focusing of electrons (beta particles) in an electronic magnetic spectrometer [RF Patent No. 2338295. Electronic magnetic spectrometer, 2008]. In the analogue method, the electrons generated by the source move under vacuum in a constant axially symmetric magnetic field, the induction of which decreases proportionally to the distance ρ from the axial axis according to the law B ~ ρ ^-α , where α = 0.5. The magnetic field of this configuration holds the electrons near a stationary trajectory - a circle of radius ρ ₀ and carries out their precise focusing on a target located at an axial angle $$\pi$$$$\sqrt{2}$$

to source. The main disadvantage of this technology is the continuity of the process of motion and focusing of electrons, which does not allow using it to accumulate the flow energy.

The technology of acceleration of electrons (beta particles) in a betatron was taken as a prototype [TSB, vol. 27, third edition, Moscow: Izd. "Soviet Encyclopedia", 1977, p.110], which consists in the following. The electrons generated by the electron gun move under vacuum in an alternating axially-symmetric magnetic field of the betatron type, which is characterized by the following parameters.

The magnetic field induction decreases in proportion to the distance ρ from the axial axis according to the law B ~ ρ ^-α , where α = 0.6, while the value of the magnetic field induction B ₀ on a stationary path - a circle of radius ρ ₀ , is half the average value of the magnetic field induction B _avg inside this circle B ₀ = 0.5 · V _av The frequency of change in the magnetic field induction is 10-10 ³ Hz.

Under the action of a magnetic field with the indicated parameters, electrons move near a stationary trajectory, crossing it many times. At the same time, acceleration of electrons occurs under the action of the arising induction electric field. The process is periodic in nature and is carried out in time intervals corresponding to an increase in the magnetic field in a fixed direction. In the process of acceleration, the electrons make about 10 ⁵ -10 ⁶ revolutions and after reaching the required energy 1-150 MeV are removed from the stationary path to the target. The withdrawal of electrons to the target is carried out by creating at the end of the acceleration period an additional pulsed field that violates the betatron condition.

We indicate the following disadvantages of the prototype.

1. The technology of electron acceleration in a betatron does not allow the accumulation of energy due to the accumulation of electrons over several periods of the process due to the unidirectional nature of the movement of electrons along a stationary circular path.

2. The presence of an electron gun of a betatron implies the use of various types of fields to obtain and accelerate electrons, which makes it difficult to coordinate both processes.

3. The technology for removing electrons from the acceleration region by creating an additional magnetic field makes it difficult to match the magnetic field of the betatron.

4. The applied technology for producing electrons in the electron gun of the betatron does not allow to achieve high values of the electron current strength due to the small area of the emitted surface in the electron gun.

5. The technology implemented in the prototype does not allow the precise focusing of electrons on the target due to the large number of revolutions made by the electrons during acceleration. The radius of the focal spot is equal to the amplitude of the electron vibrations relative to the stationary trajectory, which results in the impossibility of obtaining a large surface power density on the target.

6. The effective use of the electron acceleration process is only 25%, since the acceleration of particles in the betatron is carried out only during the 1/4 period of the change in the magnetic field.

7. The technology used to remove the flow of accelerated particles from the acceleration region makes it impossible to focus them precisely on the target, as is the case in magnetic spectrometers.

The objective of the proposed method is to obtain a high energy density of the flow of charged particles on the target, which is achieved by increasing the number of electrons in the stream and their precise focusing.

This problem is solved by a sequence of processes that periodically repeats over time: generating a stream of charged particles, accelerating, focusing deceleration and defocusing, with a frequency of magnitude change of the magnetic field of 10 ⁵ -10 ⁸ Hz, and the output of the flux energy occurs by changing the magnitude of the inductance of the magnetic field on a stationary trajectories in the direction of increase or decrease, subject to the axial symmetry of the magnetic field.

All these processes are carried out under the influence of the same variable axially symmetric magnetic field of the betatron type, which allows them to be carried out in a coordinated mode, under the following conditions, namely:

- the magnetic field induction in the area of the stationary trajectory decreases in proportion to the distance ρ from the axis of symmetry according to the law B ~ ρ ^-α , where α ~ 0.5 to fulfill the condition of precision focusing;

- the induction of the magnetic field B ₀ on a stationary trajectory, a circle of radius ρ ₀ , is half the average value of the magnetic field B inside this circle B ₀ = 0.5 · In _sr ;

- the frequency of change in the magnetic field induction, depending on the type of accelerated particles - electrons or ions, is ν = 10 ⁵ -10 ⁸ Hz, and for electrons ν = 10 ⁷ -10 ⁸ Hz, and ions ν = 10 ⁵ -10 ⁶ Hz . In this case, the region of motion of the charged particles will be limited by an axial angle less than 2π, and therefore, the paths of the charged particles will not intersect the source;

- the change in the magnetic field induction in time is subject to the following periodicity condition

B (t + 2T) = B (t), B (t + T) = - B (t)

where T = ν ^-1 is the half-period of the change in the magnetic field induction;

- the source of charged particles is a system of coaxially located grounded cylinders, the ends of which have a rounding radius of ~ 10 ^-6 m and act as emitter electrodes and can increase the linear extent of the source surface without significantly reducing the density of the induction field;

- the generated particles can be both electrons and metal ions in the case of using a liquid metal ion source.

A positive technical result provided by the specified set of features consists in increasing the power density of the flow of charged particles on the target, which is due to:

- the cyclical nature of the motion of the electron flow;

- generation and accumulation of electrons in the flow from cycle to cycle;

- retention of flow;

- the lack of intersection with the flow of the source;

- braking the flow by radiation friction, and which is achieved:

- precision focusing of the electron flow on the target.

The method of accumulating energy of the flow of charged particles is illustrated by the diagram of FIG. 1, which consists of a vacuum chamber (not indicated) with source A located in it in the form of a system of coaxial cylinders (emitter electrodes), the focus point of the flux F, and the displaced target F ₁ . The planes C and A ₁ limit the movement of charged particles along a stationary trajectory of a circle of radius ρ ₀ .

In FIG. 2 shows the change in the induction of magnetic field B in time.

In FIG. 3 shows the technological processes and their order of execution: 1 - generation of charged particles, 2 - acceleration, 3 - deceleration, 4 - focusing, 5 - defocusing, 6 - radiation friction, 7 - output of the accumulated energy of the flow of charged particles.

Consider the order of technological processes in the method of accumulating energy of the flow of charged particles (Fig. 3).

1. When the alternating magnetic field increases in time in the positive direction (Fig. 1), (Fig. 2) along a stationary trajectory D - a circle of radius ρ ₀ , an induction electric field arises, the magnitude of which at the above-mentioned frequency of change of the magnetic field is sufficient for the occurrence of the effect of field emission of charged particles from the edges of the electrodes-emitters of source A.

2. Generated charged particles under the action of an induction electric field move accelerated and under the influence of a magnetic field are focused at point F.

3. When passing the focal point F, the magnetic field changes direction and becomes negative (Fig. 2), in accordance with this, the induction electric field changes the sign of acceleration and then the particles move slowly to plane C.

4. When plane C is reached, the magnetic field vanishes and again begins to increase in the negative direction. Particles stop and under the action of the arising induction field again begin to accelerate, moving in the opposite direction, after which the processes of acceleration, focusing and deceleration, defocusing are repeated in the opposite direction. In this case, due to the action of radiation friction forces, the particles change the motion in the opposite direction in the plane А ₁ , without reaching source A.

5. When the particles reach the plane A _{1, the} entire cycle of processes is repeated again.

6. After implementing the number of cycles providing the required flux density, it is necessary to increase or decrease the average value of the magnetic field induction inside the circle of a stationary trajectory. As a result of this, the particle flow shifts relative to the initial stationary trajectory of radius ρ ₀ and their precision focusing at the point F ₁ , corresponding to the new radius of the equilibrium trajectory ρ ₁ .

In FIG. _Figure 1 shows a focusing option in which the average field decreases B _cp1 <B _cp and the radius of the equilibrium path increases ρ ₁ > ρ ₀ .

The applicant does not know the method of accumulating the energy of a stream of charged particles similar to the above, as a result of this, the proposed method meets the criterion of "novelty."

Claims (1)

The process of accumulation of charged particle beam energy, comprising the processes of generation and acceleration, under the effect of the alternating magnetic field axially symmetric betatron type, whose induction in a fixed path B decreases relative to the axis, according to the law in ~ ρ ^-α, where the exponent α = 0.6, wherein the magnetic field B ₀ in a fixed trajectory circle of radius ρ ₀ is half of the mean value B _cp within the circle B ₀ = 0,5 · B _cp, characterized in that it is a periodic consecutively lnost of generation of charged particles acceleration and precise focusing and defocusing deceleration, which is performed by the same variable axisymmetric magnetic field of the betatron type of frequency variation of the magnetic field ν, where ν = 10 ⁵ -10 ⁸ Hz, with an exponent α = 0.5 in the expression for the induction of the magnetic field B, which varies according to the periodic law B (t + 2T) = B (t), B (t + T) = - B (t), where T = ν ^-1 , and the energy output of the flow of charged particles to the target is carried out by changing the induction of the magnetic field B ₀ on a stationary path.

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