RU2347943C1 - Gas-tube engine for space crafts - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to space engineering and can be used to accelerate space crafts in deep vacuum conditions. The proposed engine represents a three-section axially symmetric metal chamber arranged, partially, inside a magnetic coil with the said sections being electrically isolated from each other. The first section, if seen from left to right, accommodates the gas discharge igniter with a circular hollow cathode, the second section housing an axial-side tubular intermediate anode. The third section houses the main anode representing an elongated cylinder with its right head face closed by electrically isolated output electrode with an axial-side orifice for plasma efflux. The said main anode is fitted inside the solenoid, the output electrode comprising a correction solenoid and making a part of the three-electrode acceleration system.

EFFECT: possibility to apply high potential differences approximating to 10 to 100 kV without breakdown between acceleration system electrodes.

Description

The invention relates to the field of space engineering and can be used to accelerate the movement of devices moving in space in high vacuum.

The well-known ion engine of the European Space Research Administration is Dual-Stage 4-greed (DS4G), in which the xenon ions are accelerated using sequentially arranged four electrode gratings with a thousand millimeter aligned holes in each at an acceleration potential of 30 kV. The disadvantage of this engine is the use of an unreasonably cumbersome accelerating system, proposed at one time to obtain high currents of argon ions at accelerating voltages of the order of one kilovolt and not very suitable when using high accelerating potentials of the order of 10 ÷ 100 kV (corresponding to modern requirements for the velocity of the outflow of reactive mass) from due to the high risk of electrical breakdowns between the electrodes. The closest technical solution to the claimed device is a constant-current source of ampere range ions with one axial hole at the outlet of the gas discharge chamber and, accordingly, a fairly simple and reliable axial three-electrode accelerating system [1].

A disadvantage of the mentioned source for use in the discussed conditions is the use of a heated incandescent cathode and a number of nodes oriented to ground-based operating conditions. The aim of the present invention is the creation of a simple and reliable ion engine using accelerating potentials of the order of 10 ÷ 100 kV, as well as the possible combination in the future of this engine with a known (respectively modernized) linear ion accelerator [2] in order to bring the ion energy to 500 ÷ 1000 keV. This goal is achieved in that the ion engine is made in the form of three serially arranged axially symmetric and electrically isolated from each other hollow metal sections, of which (when considering the system from left to right), the first is a gas discharge chamber with an internal diameter of several centimeters, having a closed left metal end with axial hole, into which a partially hollow pointed electrode is inserted through the insulator, having radial holes inside the discharge chamber A hole for supplying gas to the chamber and serving as an ignition discharge anode. An annular cavity with walls of refractory metal is placed on the cylindrical wall of the chamber, open into the chamber, having a depth comparable to the radius of the chamber and serving as a hollow discharge cathode. The walls of the hollow cathode are placed between the poles of the magnet, which allows the so-called hollow cathode reverse magnetron discharge.

The second section is adjacent to the first and partially isolated from it by vacuum, with the exception of the axial metal tube (with a socket at the left end), designed to pass the discharge into the first section and serves as an intermediate anode.

The third section adjoins the second and is a hollow metal cylinder placed inside the solenoid and which is the main anode. The right end of the cylinder is closed by an electrically isolated output electrode having a special configuration, and a central hole for the discharge of electric plasma into the acceleration system in order to form an ion beam; moreover, the output electrode is part of a three-electrode system of accelerating electrodes (for example, similar to [1]).

The invention is illustrated by a schematic drawing of an ion engine.

The ion engine operates as follows. When a sufficient amount of gas is supplied and a positive potential (with respect to the housing of the first section) is applied to the central electrode, a discharge is ignited between this electrode and the hollow cathode. When this potential is connected to the second section, the discharge (which is confirmed by experience) is automatically transferred to the second section. And when the same potential is applied to the third section, the discharge current closes mainly to the case of the third section (in earlier experiments, about 15% of the discharge current was fed to the intermediate anode in the stationary mode). Since a potential equal to the cathode is applied to the output electrode, the so-called "Discharge with oscillating electrons in a longitudinal magnetic field."

Then (when switching the potential of the central electrode of the first section from the anode to the cathode), the entire inner surface of the first section becomes a hollow cathode.

The plasma generated in the discharge flows into the ion acceleration system through a central hole in the end electrode of the third section. If the ion source is coupled to a linear ion accelerator, the tube in the second section must be replaced by a coaxial system in which the inner continuous cylinder is held on the axis and connected to the outer cylinder by two thin plates. Thus, the plasma column is given a tubular shape, which in turn leads to optimization of the plasma density distribution over the radius during the selection of the ion current and the formation of an ion beam with the smallest phase volume [1]. Also, in order to increase the glow discharge current (and possibly transfer the discharge into an arc shape), self-heating disc cathodes (for example, such as pressed cathodes from a tungsten sponge impregnated with barium aluminate) can be placed in the end part of the first chamber. For different values of high-voltage power for the structural dimensions of the engine, size variations are possible within the limits indicated below. For the longitudinal and transverse dimensions of the chambers, 100 is plus or minus 50 (mm), for axial openings, the radii are 10 plus or minus 5 (mm). For operating modes: discharge potential 200-400 (V), discharge current 0.5-5 (A). Axial magnetic field 0.005-0.03 (T).

SIGNATURE TO DRAWING

1. Section ignition discharge.

2. Section of the intermediate anode.

3. Section of the main anode.

4. Anticathode.

5. The setting fire to the anode.

6. Ring hollow cathode.

7. Short solenoid (or permanent magnet).

8. Magnetic screens.

9. The intermediate anode.

10. Ring insulators.

11. The main anode.

12. Corrective solenoid.

13. The main solenoid.

14. An intermediate accelerating electrode (blocking reverse electrons).

15. The main accelerating electrode.

Literature

1. "Stationary proton beam injector with a current of 1 A and an energy of 100 keV." Atomic energy, vol. 49, issue 5, p. 266, 1980 G. Kovalsky and etc.

2. "High-current linear proton accelerator with continuous operation." Atomic energy, t.31, issue 1, 1971 B. Shembel and others (including Kovalsky G.A.).

Claims (1)

An ion engine containing an axially symmetric gas discharge chamber, which contains three metal sections electrically isolated from each other and sequentially spaced along the axis, the first, second and third, the third of which (counting from left to right), having the form of a hollow cylinder and placed inside the solenoid, it is the main discharge anode, characterized in that the first section of the gas discharge chamber contains an annular hollow cathode, the middle plane of which is separated from the end wall of the chamber, and the cathode walls are placed between the poles of the magnet, the central, igniting pointed anode rod with openings for inlet of the working gas, electrically isolated from the chamber, placed in the end wall, the second section is an extended tube with a socket on the side of the first section and is an intermediate anode, the third section is mated with an end electrode, which is electrically isolated from the chamber, has an axial hole for extracting ions from the discharge chamber, is placed in a separate short solenoid and I It is part of a three-electrode accelerating system, which, according to the configuration, corresponds to the acceleration of the near-axis ion beam due to the passage of ions at the exit from the engine of a constant potential difference of 10 ⁴ -10 ⁵ V.