Cathode of plasma accelerator (versions)

FIELD: engines and pumps.

SUBSTANCE: in compliance with first version, this cathode comprises electron emitting hollow elements, pipeline with channels to feed working body to said elements, common heat duct around every hollow element composed by the body of revolution. Heat duct material features heat conductivity factor not lower than that of the material of said hollow elements. Every said element is connected to separate channel of said pipeline while throttle is arranged in every channel of working body feed side. Note also that throttle orifice cross-sections are identical. In compliance with second version, said common heat duct entwines every said hollow element over its outer side and over its outlet end. Common heat duct outlet end is provided with holes, their axes being aligned with those of hollow electron emitting elements. Note also that flow sections of said holes in said common heat duct is not smaller than that in holes of said emitting electron hollow elements.

EFFECT: longer life, higher reliability, uniform distribution of working body over said elements.

4 cl, 2 dwg

 

The group of inventions relates to the field of electro-motors, namely to a wide class of plasma accelerators (hall, ion, magnetoplasmadynamics and others)to use in its composition cathodes. If necessary, it can also be used in related fields of technology, for example in the development of plasma sources.

Known cathode for hall and ion accelerators, made by a widespread design concept [1]. It includes a hollow emitter, made in the form of a cylindrical sleeve with one axial channel, and a pipe through which the emitter is supplied to the working body. Coaxially with the emitter is the site of heater that is used to start heating the emitter. Near the output end of the emitter (down the flow of the working fluid) is pochnoi electrode designed to initiate the arc discharge.

This type cathodes with a one-sheet emitter successfully used at low discharge currents ~1...20 A. At high discharge currents (100 level and above), these cathodes have problems with the tap of a thermal power emitted by the cathode. In [2], it was shown that the share of thermal power emitted as heat losses in the design of the cathode when it is offline tests, in which the simulator anode chamber of the engine used is Metallichesky anode, increases with the discharge current and is at the level of ~30% of full power discharge. At high discharge currents thermal power generated in the cathode becomes very large, so when the current ~100...200 And this power will be ~500...1000 watts. Problems with the heat sink in this case lead to a noticeable increase in the temperature of the emitter, which, in turn, has a negative impact on the resource characteristics of the cathode.

It is no accident that in recent times as cathodes with a one-sheet emitter hall for engines operating at high discharge currents are considered hexaboride-lanthanum cathodes, although the emission ability of these emitters significantly below are commonly used tungsten-barium chloride emitters [3], that is, their performance is considerably worse. This is due to the fact that the working temperature of the hexaboride-lanthanum cathodes significantly higher than that of the tungsten-barium chloride cathodes, i.e., the problem of heat dissipation in the hexaboride-lanthanum cathodes are solved somewhat easier.

Lack of cathodes with a one-sheet emitter is that to increase the discharge current in these cathodes is necessary to increase the surface emission. In the one-sheet emitter cylindrical form this can be achieved mainly by increasing the inner diameter of the emitter, since the emission current density is granichen known equation of Richardson-Desmana, it cannot be significantly increased without danger of overheating the emitter. A significant increase in the internal diameter of one-sheet the emitter leads to a noticeable increase in overall size of the cathode, to increase the flow of working fluid supplied to the cathode to maintain the required pressure in the inner cavity of the emitter. The increased pressure in the inner cavity of the emitter associated with the need to provide reasonable depth of penetration of the discharge into the internal cavity of the emitter, with the need to exclude the constricted binding of discharge, that is, to provide a diffuse combustion discharge inside the emitter.

Therefore, the cathode with mnohopocetnym emitter containing many coaxially between a cylindrical channels in a single body emitter, will have certain advantages in comparison with a cathode provided with a one-sheet emitter. The emitter of such a cathode [4] there will be a lot of channels, the total area of the inner surface which at the same overall characteristics of the emitters mnogopolyusnogo and one-sheet emitter is substantially larger than the area of the inner surface of a one-sheet of the emitter. That is mnogoplodnoy the emitter of this cathode will vary more developed surface emission.

But the design of the cathode, the issue is Lanna in accordance with [4], not without drawbacks. First of all, manufacturing technology mnogopolyusnogo emitter, which would provide the same properties for all channels, more complicated technology one-sheet emitter. The mechanical strength of the emitter such a complicated shape can also be low, while the modern requirements to the mechanical strength of the products of space technology is quite high. Note that some materials of the emitter does not have a high conductivity, especially if these materials are nonmetals. In this case, for example, the channels close to the Central area of the emitter, can overheat compared to peripheral spaced channels, violating the condition of uniform distribution of the heat load on each channel of the emitter, that is overloading some channels and nedogruza other. This does little to improve life characteristics of the cathode, increasing the reliability of his work.

In addition, the distribution of the flow rate of the working fluid through the channels of the emitter can be uneven. This is because in the overheated channel will increase the temperature of the working fluid, the pressure in the formation area of the plasma and, consequently, increasing the pressure of the working fluid in the channel. This increase will reduce the flow in the channel (at the fixed rate of flow raboteg the body), what, therefore, will lead to a relative increase of the flow rate of the working fluid in the other channel, with the lower temperature. The pressure decrease in the over-heated channel can lead to an increase in the depth of penetration of the plasma into the inner cavity of the working emitting electrons parts of the channel, i.e. the current density distribution for emitting electrons as part of a more heated channel can be different from the distribution of current in the other channel.

Thus, when the cathode will be observed irregularity in the mode of its individual emission channels.

This imbalance may additionally be related to the fact that the peripheral channels covered in this arrangement, a large amount of the material of the emitter than the channels of the Central part. If, for example, this emitter is tungsten-barium emitter, at which time the cathode is ash barium (basic substance, reducing the work function of electrons and ensure the effectiveness of emissions) and its depletion in the volume of the emitter, the channels of the Central part of the emitter will be depleted in barium and peripheral channels will have it in abundance. And with the phenomenon of entrainment of barium tungsten-barium chloride emitters directly connected to the life of the cathode.

Closest to the claimed technical solution and adopted the m for the prototype is the cathode plasma accelerator, made in accordance with [5] and is designed to work with the discharge current ~100 a and above. The cathode is the cathode mnogopolyusnogo type and contains hollow emitting electrons elements, which are presented in the form of longitudinal cracks between stacked with each other, a hollow cylindrical metal rods. A lot of these rods, stacked on their form, create a lot of hollow elements, while the outer surface of the output side of these rods (along with their output end parts) are working emitting electrons elements. The cathode contains the pipeline serving for supplying it working fluid. The input part is rather long rods form a multitude of channels through which directly the working body for emitting electrons elements.

Such design of the cathode is easier to manufacture compared with the design of the cathode made in accordance with [4], it has a higher mechanical strength. But it is not without drawbacks described above and typical cathode made in accordance with [4]. thermal conductivity along the metal rods forming the hollow cathode emitting electrons elements is quite high, but thermal conductivity in the radial direction across the terminals is low, because these studs are not on the will is formed monolith, they have a very small area of thermal contact with each other. In this regard, the heat transfer in the radial direction due to thermal conductivity is low and the individual terminals can overheat during operation of the cathode, thus violating the condition of uniform distribution of the heat load for emitting electrons elements formed by the rods, i.e. overloading some elements and nedogruza other. This does little to improve life characteristics of the cathode, increasing the reliability of his work.

In this regard, and the distribution of the flow rate of the working fluid in the hollow emitting electrons elements will also be uneven (see above). Moreover, this inequality can be shown to a much greater extent than in the design of the cathode made in accordance with [4], since the cathode made in accordance with [5], it is possible overflow flow through the interstices between the rods. That is, each of the hollow emitting the electrons of the elements in the cathode made in accordance with [5], not attached to a separate channel of the pipeline, which is used to supply the working fluid only in this channel, the flow of the working fluid to one or another of emitting electrons the element can be accessed from different channels of the pipeline.

It is no coincidence that when the cathode with high discharge currents, the issue is Lenogo in accordance with [5], uneven heat load for emitting electrons elements associated with the uneven distribution of the discharge current of these elements, is shown very noticeable. This often leads to strong local overheating of the individual emitting the electrons of the elements of the cathode and its subsequent destruction, as evidenced by the test results presented in [5].

The aim of the invention is to increase the life and reliability of operation of the cathode at high discharge currents (~100 a and above) by aligning temperatures hollow emitting the electrons of the elements and ensure a uniform distribution of the working fluid on these items.

The goal is solved in two versions structures of the cathode plasma accelerator.

In the first embodiment of the invention features a cathode plasma accelerator, which contains hollow emitting electrons, a pipeline with channels for supplying the working fluid to the hollow emitting electrons elements. Each of the hollow emitting the electrons of elements made in the form of a body of rotation, the outer side along generatrix covered by a single heat pipe, a material which has a coefficient of thermal conductivity not lower than the coefficient of thermal conductivity of the hollow material emitting electrons elements. Each of the hollow emitting the electrons of the elements is resident to an individual channel of the pipeline, and each channel from the supply of the working fluid has a throttle, and the cross-section of the holes chokes are made equal.

On the output side of the working fluid from the hollow emitting the electrons of the elements can be fitted sleeve with holes, the axes of which coincide with the axes of the hollow emitting the electrons of elements.

Flow areas of the openings in the sleeve can be made no more flow areas of the openings in the hollow emitting electrons elements.

Thus, in the construction of the cathode introduced only for all hollow emitting electrons, elements of heat, a material which has a coefficient of thermal conductivity not lower than the coefficient of thermal conductivity of the material of these elements. This gives you the opportunity to equalize the temperature of all hollow emitting the electrons of the elements during operation of the cathode leads to the uniform distribution of the discharge current on these items.

If, for example, when the cathode in any flooring emitting electrons item for any reason (for example, by starting a local binding of the discharge current) will increase the amount of current attributable to this element, then, accordingly, will increase the heat and will increase the temperature of this element, which will lead to a temperature rise in the heat. Due to the fact that alproved covers all without exception hollow emitting electrons elements, has a large area of thermal contact with them, has a high thermal conductivity, the overall temperature of the heat starts to rise, including will begin to rise the temperature in the junction of the heat with all the other hollow emitting electrons elements. The temperature rise in these joints due to the heat will raise the temperature of all other hollow emitting electrons elements that will enhance their emittance will increase in their current issue, increase the amount of current attributable to these items. This, consequently, will decrease the amount of current attributable to that item, in which there was a primary current that will cause, in turn, lowering its temperature. So will the temperature equalization of all emitting the electrons of the cathode elements.

It should be noted that each of the hollow emitting the electrons of elements made in the form of a body of rotation, the outer side may be covered by heat not over the entire length, but only on the length of the generatrix on the input side of the working fluid in these elements. This solution will be effective in cases where the temperature of the hollow emitting the electrons of the elements when the cathode becomes high (at the level of 2000°C or more) and thermal cooling of these elements is s can be produced more efficiently by radiation from their outer surface, than by conduction through the heat. However, each of the hollow emitting the electrons of the elements on the outer side along the length of the generatrix should be covered by a single heat pipe to equalize the temperature of all hollow emitting the electrons of the cathode elements. This technical solution can be applied to cathodes magnetoplasmadynamics engines, in which a hollow emitting electrons elements operate at very high discharge currents and correspondingly high temperatures.

To the cathode worked more steadily, to possible local changes did not lead to a redistribution of flow in a hollow emitting electrons elements, each hollow emitting the electrons of the elements is connected to a separate channel of the pipeline, which is used to supply the working fluid only in this channel. This eliminates the possibility of the transition of flow of the working fluid from one channel to another, as observed in the design of the prototype.

In addition, the channels equipped with chokes with the same cross section of the inner hole, which helps to equalize flow through separate channels, since the flow rate of the working fluid supplied to one or the other channel will be determined not so much potential changes in the pressure appropriate for the anal floors emitting electrons the element (see the above description of the prototype)as the pressure drop across the orifice installed in the channel.

However, if the hollow emitting elements of the working fluid is supplied in the form of gas or vapor, the throttle can be performed with the same diameter of the inner hole, which provides a supercritical pressure differential. This allows you to exclude the effects of changes in pressure inside the hollow emitting elements during operation of the cathode, to have all the conditions the same amount of flow of the working fluid in each floors emitting electrons the element, i.e. practically to apply in each hollow emitting electrons the element value of consumption, independent of the mode of operation of the cathode due to the fact that the flow of the working fluid in each channel will be determined in this case by the value of the sound velocity and the cross sectional area of the hole in the choke. Execution throttle with the same diameter will increase the stability and reliability of the cathode.

Thus, this solution compared to the prototype allows to align thermal load on the hollow emitting electrons elements, promotes uniform distribution of the discharge current of these elements allows to avoid strong local overheating of individual hollow emitting the electrons of the elements of the cathode at high currents is azrad (~100 a and above), leading to its destruction. This increases the life and reliability of operation of the cathode at high discharge currents.

In addition, on the output side of the working fluid from the hollow emitting elements can be mounted sleeve with holes, the closing weekend of the end parts of these items from the plasma of the arc discharge at the cathode. The holes are used for output streams of electrons of these elements. The axis of the holes in the sleeve coincide with the axes of the hollow emitting the electrons of elements, so that the current density distribution along the working surface of the hollow emitting the electrons of the elements was uniform.

The presence of such sleeve, first of all, protects the ends of the hollow emitting the electrons of elements from the plasma arc discharge. Secondly, when used as these elements tungsten-barium chloride emitters such sleeve limits the entrainment of barium as with the end faces of these emitters, and from the internal cavity emitters. If the flow areas of the openings in the sleeve is less than or equal to the reduced cross-section hollow emitting the electrons of the elements, it further restricts the release of barium from the internal cavity of these elements, that is, increases the service life of the cathode. In addition, it increases the pressure of the working fluid in the internal cavity emitting the electrons of the elements, gives the opportunity to work is atodo at low cost of the working fluid, importantly, if the cathode is used as the cathode-compensator of the thruster or the cathode-neutralizer ion engine.

For efficient operation of a heat pipe should ensure good thermal contact between the emitting element and a heat pipe. Such contact can be assured of their mutual dense planting. If this heat is not only for the equalization of temperatures between emitting the electrons elements, but also to divert significant quantities of heat capacity in the hollow emitting electrons elements and the bushing holes. Through the coupling of the heat from other components of the cathode such a heat sink can be carried out more efficiently than in the design of the prototype. It should be noted that as the main material of the heat pipe is not necessary to use structural material, such material may be, for example, liquid metal or other substance passing into the liquid state by the intense heat.

In the second embodiment, the invention features a cathode plasma accelerator, which contains hollow emitting electrons elements, the pipeline with channels for feeding hollow emitting electrons elements of the working fluid. Each of the hollow emitting the electrons of elements made in view of the body of rotation, on the outer side along the entire length of the generatrix and the output end face is covered by a single heat pipe, a material which has a coefficient of thermal conductivity not lower than the coefficient of thermal conductivity of the hollow material emitting electrons elements. Each of the hollow emitting the electrons of the elements is connected to a separate channel of the pipeline in each channel from the supply of the working fluid has a choke, while the cross-section of the holes chokes are made equal, and the output end of the single heat pipe holes, the axes of which coincide with the axes of the hollow emitting the electrons of elements, and communicating sections of holes in a single heat no more flow areas of the openings in the hollow emitting electrons elements.

The second technical solution, in which the heat pipe comprises a hollow emitting electrons elements throughout generatrix and the output end of these items, a single heat pipe, compared with the above first technical solution is characterized by a number of advantages with respect to the cathode for hall and ion engines operating at high discharge currents supplied by the emitters (typically, a tungsten baralyme or the hexaboride-lanthanum emitters), operating at moderate temperatures (~1100 to 1500°C).

First, the cathode heat is m such design together with other technical means, as described above, contributes to the further alignment of thermal performance of all hollow emitting the electrons of the elements. Secondly, the efficiency of removal of heat flow from the hollow emitting the electrons of elements to heat by conduction through a single heat at moderate temperatures (~1100 to 1500°C) is high enough, more complete coverage hollow emitting the electrons of the elements on the outer surfaces intensively removes from these elements heat flow.

Third, at high values of the discharge current of the cathode (~100 a and above) significant values of heat capacity is allocated not only in hollow emitting electrons elements, but in the area of the outlet openings of uniform heat. The inner surfaces of these holes are subjected to intense ion bombardment from the plasma arc discharge, unable to produce cooling by thermoemission, as is the hollow emitting the electrons of the elements. Thus, at high values of the discharge current of the cathode, an intense heat from this part of the cathode.

In the first technical solution of the sleeve is not designed as a single part with the heat, it is a separate part of the cathode and the heat from her side of the heat is difficult. This may overheat the sleeve at high currents that morevisit overheating of the output end parts of the hollow emitting the electrons of the elements, operating at moderate operating temperatures (see above), which are in direct thermal contact with the sleeve.

Currently designed and manufactured a laboratory model of the cathode of this type, conducted independent fire tests. The cathode was supplied with a set of tungsten-barium chloride emitters in the form of hollow cylindrical sleeves, according to test results released report. The test results are positive, the cathode steadily worked at the discharge currents from 30 to 110 And at a flow rate of the working fluid from 2 to 4 mg/day (as the working fluid was used, the inert gas xenon) low-voltage discharge ~16...18 and quite mild temperatures emitting elements ~1100...1200°C.

The essence of the proposed technical solution, in which the hollow emitting the electrons of elements made in the form of a body of rotation covered by the heat only by forming, illustrated by the scheme presented in figure 1. The cathode plasma accelerator contains hollow emitting electrons elements 1, 2, 3, a pipe 4 for supplying to the cathode of the working fluid. Hollow emitting electrons elements 1, 2, 3 on the outer side covered by a single for all elements of the heat pipe 5 and the pipe 4 before entering the emitting electrons elements 1, 2, 3 is divided into channels 6, 7, 8.

Figure 1 for example shows three such elements of cylindrical shape 1, 2, 3, cat is that on the outer side along the entire length of their form covered by a heat pipe 5.

Each of the hollow emitting the electrons of the elements 1, 2, 3 are attached to the individual channel 6, 7, 8, and each channel is 6, 7, 8 have respective orifice 9, 10, 11 with the same cross section of the inner hole 12, 13, 14. These holes can be made with an internal diameter, providing a supercritical pressure differential in the flow of working fluid through the channels 6, 7, 8.

1 shows a diagram of the cathode, which at the outlet of the hollow emitting the electrons of the elements 1, 2, 3 with the sleeve 15 with the holes 16, 17, 18. The axis of the holes 16, 17, 18 coincide with the axes of the hollow emitting the electrons of the elements 1, 2, 3. Communicating sections of the holes 16, 17, 18 in the sleeve 15 is less than the flow areas of the hollow emitting the electrons of the elements 1, 2, 3. The direction of flow of the working gas in the cathode is shown in figure 1 by the arrow.

The cathode plasma accelerator scheme is presented in figure 1, works as follows. Before starting the cathode is the start of heating, for example, through the use of ohmic startup heater (figure 1 heater not shown). After heating the hollow emitting the electrons of the elements 1, 2, 3 to a temperature that provides thermoemission electrons in the cathode through the pipe 4 is supplied to the working body in the direction shown by the arrow. Then voltage discharge between the cathode and plasma movement is the motor (during operation of the cathode part of the engine or its simulator - anode (Autonomous firing tests of the cathode), which creates conditions for the occurrence of arc discharge between the cathode and the plasma engine or simulator. Is the initiation of the arc discharge or by supplying a given voltage level (which is typical for cathodes magnetoplasmadynamics engines), or by applying voltage to special pochnoi electrode of the cathode (which is typical of the cathodes of the hall and ion engines, the diagram 1 pochnoi electrode (not shown). After the occurrence of the arc discharge starting heating of the cathode, and applying voltage to pochnoi electrode cease, the cathode continues to work with due to heat generated in the arc discharge.

This working fluid is fed to the input channels 6, 7, 8. Passing the choke 9, 10, 11, it is distributed evenly across the hollow emitting electrons to elements 1, 2, 3. Within these elements of the working body Insulza, providing burning arc discharge in the internal cavities of these elements. The heat from the arc discharge generated in the hollow emitting electrons, elements 1, 2, 3, is passed a single heat pipe 5, which equalizes the temperature of these elements 1, 2, 3 with the same expenditure of the working fluid supplied to each of these elements. It provides almost the same distribution of the discharge current on hollow amitious the m electrons elements 1, 2, 3.

Thus, the claimed technical solution by equalizing the temperatures hollow emitting the electrons of the elements when the cathode ensure uniform distribution of the working fluid on these elements allows to increase the service life, reliability and stability of the cathode at high discharge currents (~100 a and above), to avoid local overheating of individual hollow emitting the electrons of the elements, to extend operating range of discharge currents.

The essence of the proposed technical solution, in which the hollow emitting the electrons of elements made in the form of rotation of a body covered by a heat pipe for the entire length of the generatrix and the output end, illustrated by the scheme presented in figure 2. The cathode plasma accelerator scheme is presented in figure 2, contains a hollow emitting electrons elements 1, 2, 3, a pipe 4 for supplying to the cathode of the working fluid. Hollow emitting electrons elements 1, 2, 3 on the outer side covered by a single heat pipe 5 along the entire length of the generatrix and the output end of each element. Pipeline 4 before entering the hollow emitting electrons elements 1, 2, 3 is divided into channels 6, 7, 8. Figure 2 for example shows three such elements of cylindrical shape 1, 2, 3.

Each of the hollow emitting the electrons of the elements 1, 2, 3 are attached to the individual channel 6, 7, 8, and each channel is 6, 7, 8 have sootvetstvuyuschim orifice 9, 10, 11 with the same cross section of the inner hole 12, 13, 14. These holes can be made with an internal diameter, providing a supercritical pressure differential in the flow of working fluid through the channels 6, 7, 8.

At the output end of the single heat pipe 5 holes 15, 16, 17, the axes of which coincide with the axes of the hollow emitting the electrons of the elements 1, 2, 3, and flow areas of the openings 15, 16, 17 no more flow areas of the openings in the hollow emitting electrons, elements 1, 2, 3. The direction of flow of the working gas in the cathode is shown in figure 2 by the arrow.

The cathode plasma accelerator works as follows. Before starting the cathode is the start of heating, for example, through the use of ohmic startup heater (figure 2 heater not shown). After heating the hollow emitting the electrons of the elements 1, 2, 3 to a temperature that provides thermoemission electrons in the cathode through the pipe 4 is supplied to the working body in the direction shown by the arrow. Then voltage discharge between the cathode and the plasma engine during operation of the cathode part of the engine or its simulator - anode (Autonomous firing tests of the cathode), which creates conditions for the occurrence of arc discharge between the cathode and the plasma engine or simulator. Is initial the I arc discharge or by supplying a given voltage level (which is typical for cathodes magnetoplasmadynamics engines), or by submitting a voltage on a special pochnoi electrode of the cathode (which is typical of the cathodes of the hall and ion engines). After the occurrence of the arc discharge starting heating of the cathode, and applying voltage to pochnoi electrode cease, the cathode continues to work with due to heat generated in the arc discharge.

This working fluid is fed to the input channels 6, 7, 8. Passing the choke 9, 10, 11, it is distributed evenly across the hollow emitting electrons to elements 1, 2, 3. Within these elements of the working body Insulza, providing burning arc discharge in the internal cavities of these elements. The heat from the arc discharge generated in the hollow emitting electrons, elements 1, 2, 3, due to more complete coverage of these elements on the outer surfaces, and transmitted to the surfaces of the holes 15, 16, 17 of the plasma arc discharge more intensively drained from these most loaded in thermal relation to the structural elements of the cathode, which is especially important for cathodes hall and ion engines operating at high discharge currents.

In General, it can be noted that these technical solutions allow not only to increase the life and reliability of the cathode at high discharge currents, but also due to the intensive heat removal from the hollow emitting the electrons of the elements to extend the working range of the he discharge currents. While the proposed technical solutions do not differ in structural complexity, the design of such cathodes is quite high-tech.

Thus, we can say that a bunch of emitting electrons of elements covered by a single heat pipe, in which each element is equipped with an isolated channel with the installed orifice to equalize the flow rate supplied to each element, and use other features of the proposed technical solutions that can significantly improve important characteristics of the cathode.

Sources of information

1. A.Sengupta, "Destructive Physical Analysis of Hollow Cathodes from the Deep Space 1 Flight Spare Ion Engine 30,000 Hr Life Test", 29th International Electric Propulsion Conference, USA, 2005, IEPC-2005-026.

2. Muravlev VA, Shutov, V.N., "Determination of the heat capacity in the tungsten-barium cathode hall plasma engine", "technical physics Letters, volume 37, issue 4, p.31, 2011

3. D.M.Goebel, E.Chu, "High current lanthanum and should be hexaboride hollow cathodes for high power hall thrusters", 32nd International Electric Propulsion Conference, Germany, 2011, IEPC-2011-053.

4. L.D.Cassady, E.Y.Choueiri "Experimental and theoretical studies of the lithium-fed multichannel and single - channel hollow cathode" the 29 th International Electric Propulsion Conference, Princeton University, oct 31 - nov 4, 2005, IEPC-2005-094.

5. M.De Tata, R.Albertoni, P.Rossetti, F.Paganucci, M.Andrenucci, M.Cherkasova, V.Obukhov, V.Riaby, "100-hr Endurance Test on a Tungsten Multi-rod Hollow Cathode", 32nd International Electric Propulsion Conference, Germany, 2011, IEPC-2011-108.

1. The cathode plasma accelerator containing hollow emitting elec the Rhone elements, the pipeline with channels for supplying the working fluid to the hollow emitting electrons elements, wherein each of the hollow emitting the electrons of elements made in the form of a body of rotation, the outer side along generatrix covered by a single heat pipe, a material which has a coefficient of thermal conductivity not lower than the coefficient of thermal conductivity of the hollow material emitting electrons of elements, each of the hollow emitting the electrons of the elements is connected to a separate channel of the pipeline, and each channel from the supply of the working fluid has a throttle, and the cross-section of the holes chokes are made equal.

2. The cathode plasma accelerator according to claim 1, characterized in that the output side of the working fluid from the hollow emitting the electrons of the elements are installed in the bushing with the holes, the axes of which coincide with the axes of the hollow emitting the electrons of elements.

3. The cathode plasma accelerator according to claim 2, characterized in that the flow areas of the openings in the sleeve is no more flow areas of the openings in the hollow emitting electrons elements.

4. The cathode plasma accelerator containing hollow emitting electrons elements, the pipeline with channels for supplying the working fluid to the hollow emitting electrons elements, wherein each of the hollow emitting electrons element is s, made in the form of a body of rotation, the outer side along the entire length of the generatrix and the output end face is covered by a single heat pipe, a material which has a coefficient of thermal conductivity not lower than the coefficient of thermal conductivity of the hollow material emitting electrons of elements, each of the hollow emitting the electrons of the elements is connected to a separate channel of the pipeline in each channel from the supply of the working fluid has a choke, while the cross-section of the holes chokes are made equal, and the output end of the single heat pipe holes, the axes of which coincide with the axes of the hollow emitting the electrons of elements, and communicating sections of holes in a single heat no more flow areas of the openings in hollow emitting electrons elements.



 

Same patents:

FIELD: power industry.

SUBSTANCE: invention may be used when producing carbon nanotubes and hydrogen. Microwave plasma converter comprises flow reactor 1 of radiotransparent heat-resistant material, filled with gas permeable electrically conductive material - catalyst 2 placed into the ultrahigh frequency waveguide 3 connected to the microwave electromagnetic radiation source 5, provided with microwave electromagnetic field concentrator, designed in the form of waveguide-coax junction (WCJ) 8 with hollow outer and inner conductors 9, forming discharge chamber 11 and secondary discharge system. Auxiliary discharge system is designed from N discharge devices 12, where N is greater than 1, arranged in a cross-sectional plane of discharge chamber 11 uniformly in circumferential direction. Longitudinal axes of discharge devices 12 are oriented tangentially with respect to the side surface of discharge chamber 11 in one direction. Nozzle 10 is made at outlet end of inner hollow conductor 9 of WCJ 8 coaxial. Each of discharge devices 12 is provided with individual gas pipeline 13 to supply plasma-supporting gas to discharge zone.

EFFECT: invention permits to increase the reaction volume, production capacity and period of continuous operation, stabilise burning of microwave discharge.

3 cl, 2 dwg

FIELD: process engineering.

SUBSTANCE: claimed invention relates to liquid-cooled plasma torch nozzle. Said nozzle comprises nozzle nose tip bore for release said plasma jet. Nozzle nose tip outer surface is, in fact, a cylindrical surface. It has second section abutting on first section on nozzle nose tip side. Its outer surface converges toward nozzle nose tip to, in fact, the cone. Note here that there at least one fluid feed groove extending partially over the first section and over the second section at nozzle outer surface towards nozzle nose tip. Besides there is one fluid discharge groove separate from fluid feed groove extending over the second section. Note here that there at least one fluid feed groove extending partially over the first section and over the second section at nozzle outer surface towards nozzle nose tip. Besides there is one coolant discharge groove separate from fluid feed groove extending over the second section.

EFFECT: efficient cooling of nozzle nose tip, ruled out its thermal overload.

16 cl, 16 dwg

FIELD: engines and pumps.

SUBSTANCE: invention relates to RF plasma generators for ICEs. Proposed plasma RF generator comprises supply module (20) to feed excitation signal (U) to output interface in preset frequency (Fc) to fire spark (40) at plasma generation resonator (30). The latter is connected with supply module output interface. Besides, it comprises control module (10) to set supply module frequency in response to instruction on plasma RF generation. Control module comprises means to define optimum excitation frequency that can adapt preset frequency (Fc) to device resonance conditions after striking of spark.

EFFECT: possibility of control over RF plug supply in every cylinder, longer life.

8 cl, 3 dwg

FIELD: electricity.

SUBSTANCE: cathode (1) and anode (2) of an eroding pulse plasma accelerator (EPPA) are of flat shape. Between discharge electrodes (1 and 2) there are two dielectric pellets (4) made of ablating material. An end wall insulator (6) is installed between the discharge electrodes in the area of dielectric pellets (4) placement. An electric discharge initiator (9) is connected to electrodes (8). A capacitive storage (3) of the power supply unit is connected through current leads to the electrodes (1 and 2). The EPPA discharge channel is shaped by surfaces of the discharge electrodes (1 and 2), the end wall insulator (6) and end walls of the dielectric pellets (4). The discharge channel is made with two mutually perpendicular middle planes. The discharge electrodes (1 and 2) are mounted symmetrically in regard to the first middle plane. The dielectric pellets (4) are mounted symmetrically in regard to the second middle plane. A tangent to the surface of the end wall insulator (6) faced to the discharge channel is oriented at an angle from 87° up to 45° in regard to the first middle plane of the discharge channel. In the end wall insulator (6) there is a well with (7) a rectangular cross-section. In the well (7) from the cathode (1) side there are electrodes (8). A tangent to the front surface of the well (7) is oriented at an angle from 87° up to 45° in regard to the first middle plane of the discharge channel. The well (7) along the surface of the end wall insulator(6) has a trapezoid shape. The larger base of the trapezoid is located near the anode (2) surface. The lesser base of the trapezoid is located near the cathode (1) surface. At the end wall insulator (6) surface there are three straight-line grooves oriented in parallel to surfaces of the discharge electrodes (1 and 2).

EFFECT: increase in service life, reliability, pulling efficiency, efficiency of the working agent use and stability of the EPPA pull characteristics due to even evaporation of the working agent from the working area of the dielectric pellets.

9 cl, 3 dwg

FIELD: engines and pumps.

SUBSTANCE: invention relates to pressure pumps. Pressure pump with dielectric barrier for acceleration of fluid flow comprises first dielectric layer with first electrode built therein and second dielectric layer with second built-in electrode. Said first and second dielectric layers are spaced apart to make an air gal there between. Third electrode is arranged at least partially in said air gap relative to fluid flow. High-pressure signal is fed to third electrode from HV source. Said electrodes interact to generate opposed asymmetric plasma fields in said air gap to induce airflow in said gap. Induced airflow accelerates fluid flow in its travel via said air gap.

EFFECT: accelerated fluid flow in pipeline.

13 cl, 5 dwg

FIELD: electricity.

SUBSTANCE: method for modification of ionospheric plasma includes formation of artificial plasma accumulation in result of blast waves propagating from places of explosive cartridges blasting. Pyrotechnic release is made from the cartridge in radial directions, shaping of propagating blast waves is made by simultaneous explosion of all explosive cartridges, at that plasma accumulation with pulsed electromagnetic fields in it is formed in the central area of influence due to converging blast wave formed as a result of the fronts joining of some explosions.

EFFECT: increasing intensity of pulsed electromagnetic fields, increasing efficiency of near-space researches, LF radio communications and electronic jamming.

5 cl, 3 dwg, 1 tbl

FIELD: physics.

SUBSTANCE: invention relates to plasma engineering and can be used for strengthening treatment of components made of steel and nonferrous metal alloys by plasma nitriding. The disclosed method involves mounting a hollow titanium cathode in a discharge system having an anode, constantly pumping a working gas - nitrogen - through the hollow cathode, applying voltage between the anode and the hollow cathode and igniting glow discharge, the current of which is set such that in a few minutes, temperature of the hollow cathode increases to temperature close to the melting point of titanium (1668±4°C), forming a titanium nitride layer on the surface of the hollow cathode and switching discharge to a low-voltage arc mode with a thermionic cathode. The cathode is then hardened in the arc mode, for which the arc discharge current is increased while simultaneously reducing combustion voltage thereof, keeping temperature of the hollow cathode close to the melting point of titanium and maintaining discharge in such a mode for 40 minutes.

EFFECT: enabling measurement of discharge parameters in a wider range limited by reaching the melting point of titanium nitride, and multifold increase in discharge current.

6 dwg

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment, namely to instruments for realisation of plasma coagulation of tissue. Instrument includes device for supply of oxidative means, device for gas supply and electrode for obtaining plasma, device for prevention of tissue carbonisation in the process of plasma coagulation. Device for carbonisation prevention in made with possibility of preparing gas and oxidative means mixture to obtain gas and oxidative means plasma, with two-component spray device for supply of oxidative means being is self-sucking two-component spray-type device.

EFFECT: application of invention makes it possible to increase uniformity of tissue processing.

12 cl, 8 dwg

FIELD: physics.

SUBSTANCE: invention relates to electric-arc plasmatrons with water stabilisation of electric-arc, and can be effectively used when cutting any metal. The electric-arc plasmatron has coaxially and series-arranged cooled cathode assembly, insulator, swirl chamber, a system for feeding plasma-supporting gas and liquid and an anode assembly with an anode nozzle, placed in the inter-electrode gap relative the cathode assembly and forming a cavity for liquid stabilisation transitioning at the outlet into a water screen. The cavity in the anode nozzle is made of two interfaced conical surfaces: a wall which is 2/3 of the length of the initial section of the cavity makes an inclination angle α1=5-10°, then α2=30-45° to the cylindrical section at the outlet, the length of which is equal to 0.5-0.8 times its diameter, wherein parameters of the anode nozzle define the nature of liquid stabilisation of the plasma jet and protective characteristics of the water collector-distributor.

EFFECT: simple design, high power of the plasmatron, enthalpy of the obtained plasma and cutting speed.

1 dwg

FIELD: electricity.

SUBSTANCE: transformer-type plasmatron has a closed gas-discharge chamber with a system of magnetic conductors with primary windings, a holder for holding the treated material and a power supply. The gas-discharge chamber has a working chamber and one or more identical flat-topped chambers with a smaller inner diameter and a shorter or equal length, each having a system of dismountable magnetic conductors with primary windings, and arranged so as to form a closed path for gas discharge current with the working chamber.

EFFECT: considerably higher rate and quality of the process and efficiency of the apparatus.

5 cl, 1 dwg

FIELD: engines and pumps.

SUBSTANCE: invention can be used for tests of plasma source cathodes or those for high-current plasma engines. Proposed method comprises cathode independent fire tests. Here, cathode is switched on many times. Cathode basic degradation parameters are measured and tests are conducted at forced operating conditions. Tests are divided into steps. At every step, one of cathode degradation factors is augmented and cathode is simultaneously subjected to all other degradation factors under operating conditions. Every degradation factor is augmented at least one time.

EFFECT: accelerated test procedure, possibility to analyse the effects of every degradation factor to cathode life.

7 cl, 4 dwg

FIELD: transport.

SUBSTANCE: invention relates to jet-propelled moving facilities, predominantly in free outer space. Proposed moving facility contains body (1), payload (2), control system and at least one ring system of superconductive focusing-deflecting magnets (3). Each magnet (3) is attached to body (1) by load-bearing element (4). It is preferable to use two described ring systems located in parallel planes ("one above the other"). Each ring system is designed for long-term storage of highest-energy electrically charged particle flux (5) (relativistic proton flux) circulating in this system. Fluxes in ring systems are mutually antithetical and are inserted in these systems before flight (on launch orbit). To output of one of the magnets (3) of "upper" ring system a device (6) for part of flux (7) extraction to outer space is attached. Similarly, part of flux (9) is extracted via device (8) of one of the magnets of "lower" ring system. Fluxes (7) and (9) create jet propulsion. Devices (6) and (8) can be made in the form of deflecting magnetic system, neutraliser of flux electric charge and undulator.

EFFECT: higher energy-conversion efficiency of working medium creating thrust.

4 cl, 2 dwg

FIELD: physics.

SUBSTANCE: invention relates to beam engineering and can be used to compensate (neutralise) for spatial charge of a beam of positive ions of electro-jet engines, particularly for use in propulsion devices of micro- and nanosatellites. The method of neutralising spatial charge of an ion stream of an electro-jet propulsion device by emitting electrons through multiple autoemission sources. Sources are placed around each of the electro-jet engines of said device. Emission currents of separate autoemission sources or groups of said multiple autoemission sources are controlled independent of each other.

EFFECT: reduced consumption the working medium of an electro-jet engine, including a multimode electro-jet engine or a multi-engine apparatus, minimum time for switching to neutralisation operating mode and fast switching of electron current according to the operating mode of said electro-jet engine, optimising transfer of electrons into the neutralisation region in order to reduce divergence of the ion beam or deviation thereof, thereby changing the direction of ion thrust.

6 cl

FIELD: engines and pumps.

SUBSTANCE: invention relates to space engineering, particularly, to electric jet engines and is designed to control space craft of low thrust (up to 5 N). Cyclotron plasma engine comprises plasma accelerator housing, solenoids (inductors) and electric circuit with compensating cathodes. Note here that self-contained ion source, electron and ion flow splitter. Asynchronous cyclotron makes said plasma accelerator. Cyclotron is divided into dees by two coaxial pairs of parallel grids with clearances. Said dees make homogeneous, identical and invariable electric fields of opposite-direction of electric-field vectors. Cyclotron comprises the ferromagnetic adapters with inductors in quantity complying with the number of plasma accelerator outlet channel thrust development directions. Outlet straight gas dielectric channels of this engine communicate with said main adapters via pass electric valves. Said channels are communicated via ferromagnetic adapters wit inductors.

EFFECT: higher specific burn, decreased weight and overall dimensions, lower power consumption.

3 cl, 2 dwg

FIELD: electricity.

SUBSTANCE: cathode (1) and anode (2) of an eroding pulse plasma accelerator (EPPA) are of flat shape. Between discharge electrodes (1 and 2) there are two dielectric pellets (4) made of ablating material. An end wall insulator (6) is installed between the discharge electrodes in the area of dielectric pellets (4) placement. An electric discharge initiator (9) is connected to electrodes (8). A capacitive storage (3) of the power supply unit is connected through current leads to the electrodes (1 and 2). The EPPA discharge channel is shaped by surfaces of the discharge electrodes (1 and 2), the end wall insulator (6) and end walls of the dielectric pellets (4). The discharge channel is made with two mutually perpendicular middle planes. The discharge electrodes (1 and 2) are mounted symmetrically in regard to the first middle plane. The dielectric pellets (4) are mounted symmetrically in regard to the second middle plane. A tangent to the surface of the end wall insulator (6) faced to the discharge channel is oriented at an angle from 87° up to 45° in regard to the first middle plane of the discharge channel. In the end wall insulator (6) there is a well with (7) a rectangular cross-section. In the well (7) from the cathode (1) side there are electrodes (8). A tangent to the front surface of the well (7) is oriented at an angle from 87° up to 45° in regard to the first middle plane of the discharge channel. The well (7) along the surface of the end wall insulator(6) has a trapezoid shape. The larger base of the trapezoid is located near the anode (2) surface. The lesser base of the trapezoid is located near the cathode (1) surface. At the end wall insulator (6) surface there are three straight-line grooves oriented in parallel to surfaces of the discharge electrodes (1 and 2).

EFFECT: increase in service life, reliability, pulling efficiency, efficiency of the working agent use and stability of the EPPA pull characteristics due to even evaporation of the working agent from the working area of the dielectric pellets.

9 cl, 3 dwg

FIELD: engines and pumps.

SUBSTANCE: proposed device comprises at least: one primary ionisation and acceleration circular channel 21 with open end, anode 26 accommodated inside said channel, cathode 30 located outside said channel, at its outlet, and magnetic circuit 4 to induce magnetic field in a portion of said circular channel. Magnetic circuit comprises at least circular inner wall 22, circular outer wall 23, and bottom 4 connected said walls to make magnetic circuit outlet part. Note here that said circuit 4 can induce magnetic field at circular channel outlet 21 independent of azimuth.

EFFECT: increased probability of ionising collisions between electron and inert gas atoms.

46 cl, 6 dwg

FIELD: engines and pumps.

SUBSTANCE: proposed engine comprises main circular ionization and acceleration channel, at least one hollow cathode, circular anode, pipe with header to feed anode with ionised gas, and magnetic circuit to induce magnetic field in said main circular channel. Said main circular channel is composed around engine axis. Said node is arranged aligned with said main circular channel. Magnetic circuit comprises at least one axial magnetic core surrounded by first coil and inner rear polar tip that makes a solid of revolution, and several outer magnetic cores surrounded by outer coils. Said magnetic circuit incorporates extra, in fact radial outer first polar tip making the concave inner peripheral surface and, in fact, radial inner second polar tip making the convex outer peripheral surface. Said peripheral surface represent corrected profiles. The latter differ from circular cylindrical surface to make variable-width clearance there between. Maximum clearance is located at sections aligned with location of outer coils. Minimum clearance is set at sections located between said outer coils to produce uniform radial magnetic field.

EFFECT: higher power output, decreased amount of wires and their weight.

7 cl, 8 dwg

FIELD: engines and pumps.

SUBSTANCE: stationary plasma engine model comprises circular dielectric discharge chamber accommodating circular gas distribution anode, magnetic system and cathode. Extra ring-shape gas distributor is arranged inside said discharge chamber and attached via insulator to gas distribution anode. Said ring has coaxial blind holes arranged uniformly in azimuth, each being stopped by cover with a through calibrated bore. Every said blind bore and cover makes a vessel filled with crystalline iodine. Note here that extra ring-shape gas distributor is arranged inside said discharge chamber so that said calibrated holes face said gas distribution anode.

EFFECT: stationary plasma engine running on crystalline iodine, lower costs at first stage of the analysis of engine efficiency and characteristics.

2 dwg

FIELD: engines and pumps.

SUBSTANCE: engine is composed by anode, cathode and electrode gap filled with liquid film-like working fluid. Said anode and electrode are made of m-metal while magnetic field source is electrically insulated from electrodes by ferrite core pickups.

EFFECT: higher engine efficiency and specific performances.

1 dwg

FIELD: transport.

SUBSTANCE: proposed method consists in creating field-emission electrons of density over 1000 A/m2 at regular intervals nearby aircraft airfoil at electric field intensity making, at least, 1 V/mcm. Negative-charge air oxygen ions are generated and accelerated by electric field of section electrode system distributed said airfoil to generate ionised airflow about said airfoil and lift acting at aircraft.

EFFECT: aircraft increased power efficiency.

2 dwg

FIELD: space engineering; ground tests and operation in space of plasma jet engines and electric jet engine plants.

SUBSTANCE: proposed method includes performance of shortened endurance tests which are part of total service life; in conducting these tests, erosion of discharge chamber (δt), change in thrust at the beginning (Fo) and in the course (ft) of shortened endurance tests are measured, regressive analysis for determination of approximating dependences is performed in form of monotonic function of erosion of discharge chamber and thrust versus time of operation; prediction of behavior of thrust is performed by definite dependence Ft=f(Fo, t), at the beginning of shortened tests and in the course of conducting these tests erosion areas (So, St) are additionally determined; approximating dependence of erosion area versus time St=f(t) and functional dependence of thrust versus erosion area F=f(k,S) are determined by regressive analysis, where k is proportionality factor between thrust and erosion area which are taken into account in prediction of thrust behavior during total service life; thrust is determined by dependence Ft=f(Fo, k,.St, So)

EFFECT: enhanced accuracy of prediction of parameters of stationary plasma jet engine.

2 dwg

Up!