CN116544083A - Long-life quick start hollow cathode with three-dimensional double-rotation heater - Google Patents
Long-life quick start hollow cathode with three-dimensional double-rotation heater Download PDFInfo
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- CN116544083A CN116544083A CN202310521750.2A CN202310521750A CN116544083A CN 116544083 A CN116544083 A CN 116544083A CN 202310521750 A CN202310521750 A CN 202310521750A CN 116544083 A CN116544083 A CN 116544083A
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- 239000000919 ceramic Substances 0.000 claims abstract description 131
- 238000010438 heat treatment Methods 0.000 claims abstract description 120
- 239000002131 composite material Substances 0.000 claims abstract description 5
- 229910052751 metal Inorganic materials 0.000 claims abstract description 5
- 239000002184 metal Substances 0.000 claims abstract description 5
- 239000011810 insulating material Substances 0.000 claims abstract description 3
- 230000000149 penetrating effect Effects 0.000 claims description 27
- 238000004804 winding Methods 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 12
- 208000028659 discharge Diseases 0.000 claims description 11
- 230000000694 effects Effects 0.000 claims description 5
- 230000008602 contraction Effects 0.000 claims description 3
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 claims description 3
- 238000003466 welding Methods 0.000 claims description 2
- 230000009977 dual effect Effects 0.000 claims 8
- 239000000463 material Substances 0.000 description 13
- 238000010586 diagram Methods 0.000 description 8
- 230000002035 prolonged effect Effects 0.000 description 8
- 229910025794 LaB6 Inorganic materials 0.000 description 7
- 238000004321 preservation Methods 0.000 description 5
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 4
- 239000000306 component Substances 0.000 description 4
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 230000017525 heat dissipation Effects 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 229910052582 BN Inorganic materials 0.000 description 2
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 2
- WYTGDNHDOZPMIW-RCBQFDQVSA-N alstonine Natural products C1=CC2=C3C=CC=CC3=NC2=C2N1C[C@H]1[C@H](C)OC=C(C(=O)OC)[C@H]1C2 WYTGDNHDOZPMIW-RCBQFDQVSA-N 0.000 description 2
- 230000006698 induction Effects 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- 229910001120 nichrome Inorganic materials 0.000 description 2
- 239000011224 oxide ceramic Substances 0.000 description 2
- 229910052574 oxide ceramic Inorganic materials 0.000 description 2
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
- DECCZIUVGMLHKQ-UHFFFAOYSA-N rhenium tungsten Chemical compound [W].[Re] DECCZIUVGMLHKQ-UHFFFAOYSA-N 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- WMTSAHAFZXEJBV-UHFFFAOYSA-N [Ba].[W] Chemical compound [Ba].[W] WMTSAHAFZXEJBV-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000009730 filament winding Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03H—PRODUCING A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03H1/00—Using plasma to produce a reactive propulsive thrust
- F03H1/0087—Electro-dynamic thrusters, e.g. pulsed plasma thrusters
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
- H01J1/02—Main electrodes
- H01J1/025—Hollow cathodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
- H01J1/88—Mounting, supporting, spacing, or insulating of electrodes or of electrode assemblies
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Solid Thermionic Cathode (AREA)
Abstract
The invention provides a long-life quick-starting hollow cathode with a three-dimensional double-spiral heater, which consists of a touch electrode, a ceramic base, a cathode tube, a heater, an air duct, a wiring lug and a wire, wherein the touch electrode is arranged on the hollow cathode; the touch electrode consists of a touch electrode top and a touch electrode tube body, and is a hollow cathode ignition; the ceramic base is a part made of insulating materials, the center of the ceramic base is a gas guide pipe hole, and a hole slightly smaller than the gas guide pipe hole is a wire leading-out hole; the cathode tube consists of a cathode top and a cathode tube body, the cathode tube is used for conducting air flow, and an emitter is placed; the heater consists of a heating wire, a leading-out wire, inner heat conducting ceramic and outer heat conducting ceramic; the inner heat-conducting ceramic and the outer heat-conducting ceramic are heater main bodies, and adopt an inner-outer double-layer composite mode, and the same heating wire is sequentially wound on the inner heat-conducting ceramic and the outer heat-conducting ceramic from the contact position of the same heating wire and the leading-out wire; the air duct is a metal pipe with a shoulder part; the connection lug is a part for connecting the hollow cathode with an external power supply.
Description
Technical Field
The invention belongs to the technical field of aerospace electric propulsion, and particularly relates to a hollow cathode part.
Background
With the development of commercial aerospace and various satellites, a Hall thruster has the advantages of simple structure, small volume, total impulse and large thrust ratio, and becomes the electric propulsion device with the largest in-orbit application quantity. The hall thruster needs to use a hollow cathode as an electron source and a neutralizer, which is one of the core components of the hall thruster. Rapid start-up is one of the main development directions of hollow cathodes in the present stage. The current starting of the hollow cathode is mostly to utilize ohmic effect to energize the heating wire with constant current, heat the emitter from normal temperature to the appointed temperature, make the emitter have thermionic emission ability, this process determines the speed of starting the hollow cathode, the shorter this process is used, the better the starting performance of the hollow cathode is, therefore, it is necessary to have as much heating power as possible on the emitter of unit length, therefore, the heating process of the hollow cathode is very important in the hollow cathode.
Because of the different emitter materials, the commonly used emitter materials include LaB6, baO-W, C12A7, and the like, wherein LaB6 needs to be heated to 1600 ℃, and for two emitters of BaO-W and C12A7, self-sustaining discharge can be realized only by heating to about 1300 ℃, when the temperature is too low, the thermal emission electron efficiency is lower, however, the service life of the emitter is affected by too high temperature, even when the emitter melts, and the plasma generates joule heating in the self-sustaining discharge process, which can reach a higher temperature, so that heat dissipation is needed in the self-sustaining discharge stage after ignition, and the requirement of long service life can be met. Therefore, the hollow cathode cannot meet two contradictory requirements by means of enhanced heat dissipation or enhanced heat preservation, and always has a trade-off between the two. Therefore, the heat dissipation requirement of self-sustaining discharge can be ensured by using simple heat preservation measures, and the starting performance is improved by a method of improving the heating power.
By ohm's law: the heating effect is more pronounced at a constant current where the resistance is greater, so it is desirable that the resistance of the heater wire is as great as possible during use.
The heater wire is a single point failure element and the environment within the hollow cathode is extremely harsh, and the need to extend its life requires the use of thicker heater wires, which is contrary to the requirement of large electrical resistance required for heating. The space inside the hollow cathode is very limited, which also makes it difficult to extend the length of the heating wire.
Most filament winding methods at present lengthen the length of the heating filament by lengthening the length of the heat conductive ceramic around which the heating filament is wound to increase the number of turns, while the length of the emitter to be heated is fixed, and the length of the winding area of the heating filament often exceeds the length of the emitter, which results in not high heating efficiency.
Meanwhile, the most adopted spiral pipe winding mode at present leads the heating wire to form a solenoid around the cathode tube, so that the heating wire can be influenced by a magnetic field under the impact of the instantaneous current of ignition, induced voltage and induced current are generated, and even the heating wire can be directly blown, which is also a big factor influencing the service life of the heating wire and even the service life of the hollow cathode.
Therefore, the length of the heater of the hollow cathode, which is required to be wound by the heating wire, is as much as possible acted on the emitter, so that the heating power obtained by the emitter with the length is increased, the heating speed is improved, and the waste of the heating power is avoided; the starting performance of the hollow cathode is improved, the working of an emitter of the hollow cathode is ensured not to be overheated, and the requirement of long service life is met; the thicker heating wire is used as much as possible, so that the service life of the heating wire is prolonged; the space utilization rate inside the hollow cathode is improved while the length of the heating wire is prolonged, and the length and the volume of the hollow cathode are reduced; the influence of the ignition magnetic field is reduced or even eliminated as much as possible, and the service life of the hollow cathode is prolonged from the angles of the heating wire and the emitter.
The novel heating wire material is difficult to be used for exploring the material profession, and the time cost and the capital cost are high; secondly, the diameter of the heating wire is reduced, but the heating wire is weaker and runs counter to the goal of long service life; thirdly, the length of the heating wire is prolonged, and the method is widely applied. In the heating device described in CN 112543522A, the length of the wound heating wire is required to be increased only by increasing the number of turns of the wound wire, and as the heating device, the length of the emitter to be heated is fixed, and the length of the wound heating wire section generally exceeds the length of the emitter, which results in not high heating efficiency. While the schematic diagram given in CN 109767959A is that the heating wire and the emitter are equal in length, but the relationship between the length of the winding area of the heating wire and the length of the emitter is not given here, in general, the length of the winding area of the heating wire is not smaller than the length of the emitter, because the heating power in this case is generally low, and rapid ignition cannot be achieved; if the length of the emitter is smaller than the length of the winding area of the heating wire, waste of heating power is caused, and the gain of shortening the heating time obtained after increasing the heating power is reduced as the winding area becomes longer. The heater mentioned in CN 109599309a adopts a serpentine winding method, which effectively reduces the induced voltage and induced current generated by the influence of the ignition moment magnetic field, but the winding length of the heating wire is shortened in the application of the winding method, because the serpentine winding heating wire has a plurality of 180-degree turns, the heating wire is prevented from being broken in the re-winding process in consideration of the rigidity and toughness of the heating wire, and the turning radius cannot be too small, which occupies a considerable space. Meanwhile, the 180 turns can also cause the part to be a weak link for stress concentration of the heating wire, and the turns are a plurality of weak links, so that the service life of the heating wire is greatly threatened.
Disclosure of Invention
The length of the heater wire wound on the emitter is as much as possible in the heater of the hollow cathode, so that the heating power obtained by the emitter with the length is increased, the heating speed is improved, and the heating power waste is avoided; the starting performance of the hollow cathode is improved, the working of an emitter of the hollow cathode is ensured not to be overheated, and the requirement of long service life is met; the thicker heating wire is used as much as possible, so that the service life of the heating wire is prolonged; the space utilization rate inside the hollow cathode is improved while the length of the heating wire is prolonged, and the length and the volume of the hollow cathode are reduced; the influence of the ignition magnetic field is reduced or even eliminated as much as possible, and the service lives of the heating wire and the emitter are prolonged.
Therefore, the invention provides a long-life quick-starting hollow cathode with a three-dimensional double-rotation heater, which consists of a touch electrode, a ceramic base, a cathode tube, a heater, an air duct, a wiring lug and a wire, wherein the heater consists of a heating wire, a leading-out wire, inner heat-conducting ceramic and outer heat-conducting ceramic.
The inner heat conducting ceramic and the outer heat conducting ceramic are heater main bodies, an inner and outer double-layer composite mode is adopted, the same heating wire is sequentially wound on the inner heat conducting ceramic and the outer heat conducting ceramic from the contact position of the heating wire and the leading-out wire, the outer heat conducting ceramic is provided with two wire penetrating holes, an initial wire penetrating hole (2-1) at one end is the starting point of winding the heating wire on the outer heat conducting ceramic, a terminal wire penetrating hole (2-2) at the other end is the terminal point of the heating wire, the heating wire continuously penetrates through the wire penetrating hole (3-1) of the inner heat conducting ceramic after penetrating through the terminal wire penetrating hole (2-2) to contact with the cathode tube, a closed loop is formed, and the cathode tube is used as the cathode of the heating wire. The double-layer composite winding heating wire in space can enable the length of the heating wire to be doubled, effectively utilizes the space inside the hollow cathode, improves the heating power of the emitter in unit length, and can reduce the preheating time and improve the heating efficiency. It is worth noting that the winding direction of the inner heat conducting ceramic is required to be identical to that of the outer heat conducting ceramic, and the same heating wire passes back and forth for two paths, so that the current directions of the two paths are opposite, and the induction currents can cancel each other, so that the influence of a magnetic field at the moment of ignition is avoided. Because the heater uses a multilayer ceramic structure and has a certain heat preservation effect, other heat preservation measures can be omitted.
The structure and function of each component will be described in detail with reference to the accompanying drawings
Fig. 8 is a block diagram of a ceramic base 22, which is a component made of an insulating material, wherein the center of the ceramic base is an air duct hole, a hole near the air duct hole is an extraction hole, the diameter of the ceramic base is not smaller than the outer diameter of a touch electrode, a boss with a smaller diameter is arranged on the ceramic base, the diameter of the boss is the same as the inner diameter of the touch electrode, and four threaded holes are formed around the boss and are used for being matched with four fixing holes on the touch electrode to finish the fixing of the touch electrode.
Fig. 7 is a structural view of an air duct 24, which is a metal pipe provided with a shoulder, and an air duct connecting ring 24-1 is a region connected with a cathode tube, the outer diameter of which is equal to the inner diameter of the cathode tube, and the two are connected by welding after the air duct connecting ring is sleeved on the cathode tube. The small end of the shoulder 24-2 is equal to the outer diameter of the cathode tube, the diameter of the large end is at least 1mm larger than that of the small end, and the tail 24-3 of the air duct is used for air supply.
Fig. 9 shows a lug 19, which is a part for connecting a hollow cathode of the lug with an external power supply, wherein the round hole end 19-1 of the lug is a round hole through which a screw can pass, and the diameter of the lug is the same as that of a fixing bolt, in this example, a bolt with the aperture of 2mm for matching with M2 is adopted, and the lug terminal 19-2 is connected with a wire.
The emitter 5 shown in fig. 4 is a cylindrical structure, and is characterized by being resistant to bombardment and low in work function, and has the function of releasing electrons after heating, and common emitter materials include LaB6, impregnated barium tungsten, C12A7 and the like. The emitter is positioned in the cathode tube and is close to one side of the cathode top (17-2), and the emitter and the cathode top are in interference fit.
Fig. 6 is a view of the structure of the touch electrode, the touch electrode 25 is composed of a touch electrode top and a touch electrode tube, the touch electrode top hole is about 3-4mm in the center of the touch electrode top, the touch electrode group is used for igniting a hollow cathode,
fig. 5 is a structural diagram of a cathode tube, the cathode tube 5 is composed of a cathode top and a cathode tube body, a cathode tube top hole is arranged in the center of the cathode top, the size is 1-2mm, the main function of the cathode tube is to conduct air flow, and an emitter is placed,
fig. 3 is a structural diagram of an external heat-conducting ceramic, the external heat-conducting ceramic 2 is provided with two wire penetrating holes, namely an external heat-conducting ceramic starting wire penetrating hole 2-1 and an external heat-conducting ceramic ending wire penetrating hole 2-2, the external heat-conducting ceramic starting wire penetrating hole mainly aims at penetrating a heating wire from the inside, the heating wire penetrates into the external heat-conducting ceramic ending wire penetrating hole after being wound on the external heat-conducting ceramic spiral groove 2-3, and the external heat-conducting ceramic boss 2-4 is a semi-circular ring and mainly aims at setting the external heat-conducting ceramic ending wire penetrating hole 2-2.
Fig. 2 is a structural diagram of an internal heat-conducting ceramic, wherein an internal heat-conducting ceramic threading hole 3-1 and an internal heat-conducting ceramic spiral groove 3-2 are arranged on the internal heat-conducting ceramic 3, the total length of the internal heat-conducting ceramic is equal to that of an external heat-conducting ceramic, and the external heat-conducting ceramic termination threading hole 2-2 and the internal heat-conducting ceramic threading hole 3-1 can be overlapped into a through hole by axes.
The lead-out wire 20 of the touch electrode is a standard component, generally a high-current wire, and is used for connecting a power supply to power the touch electrode, and a multi-core copper wire which allows ionization by more than 2A is generally selected;
cathode wiring 23 is a standard, typically a high current wire, for grounding the cathode tube, typically selected to allow passage of multi-core copper wire over ionization 2A;
the fixing screw 22 is a standard component, and in this example, an inner hexagon bolt of M2 is used.
The invention has the beneficial effects that:
the length of the heating wire is increased, so that the heating efficiency and the heating power are increased, and meanwhile, even under the condition that the heating power is enough, the heater structure can use thicker heating wires, so that the reliability is enhanced; the heating power of the emitter in unit length is improved, the preheating time can be reduced, and the heating efficiency can be improved; the starting performance of the hollow cathode is improved, the working of an emitter of the hollow cathode is ensured not to be overheated, and the requirement of long service life is met; the double-layer anti-rotation composite winding heating wire can reduce the influence of an induced magnetic field at the moment of ignition; the space inside the hollow cathode is effectively utilized, and the length and the volume of the hollow cathode are reduced.
Drawings
Fig. 1 is a general cross-sectional view of a heater.
Fig. 2 is a diagram of the internal heat conducting ceramic structure.
Fig. 3 is a structural diagram of an external thermally conductive ceramic.
Fig. 4 is a diagram of a structure of an emitter.
Fig. 5 is a structural view of a cathode tube.
Fig. 6 is a view of a touch electrode structure.
Fig. 7 is a structural view of the airway tube.
Fig. 8 is a structural view of a ceramic base.
Fig. 9 is a structure view of a tab.
The reference numerals in the figures are illustrated as follows: 1: a heating wire; 2: an outer thermally conductive ceramic; 3: an inner thermally conductive ceramic; 4: an emitter; 5: a cathode tube;
6: a wire is led out; 19, a wiring lug; 20: a contact electrode lead wire;
21: a fixing screw; 22: a ceramic base; 23: cathode wiring; 24: an air duct; 25: a touch electrode;
2-1: an outer heat conducting ceramic initial threading hole; 2-2: the external heat-conducting ceramic terminates the threading hole; 2-3: an outer thermally conductive ceramic helical groove; 2-4: an outer thermally conductive ceramic boss;
3-1: an internal heat conducting ceramic threading hole; 3-2: an inner heat conducting ceramic spiral groove;
5-1: a cathode tube top hole; 5-2: a cathode top; 5-3: a cathode tube body;
19-1: a lug round hole; 19-2: a lug terminal;
25-1: a contact pole top hole; 25-2: touching the top of the holding electrode; 25-3: a contact electrode tube; 25-4: a contact electrode fixing hole;
24-1: an airway tube connection ring; 24-2: an airway tube fixing shoulder; 24-3: the tail part of the air duct;
22-1: leading out a wire hole; 22-2: a gas pipe hole; 22-3: a fixing hole;
Detailed Description
The technical solution will be elucidated in detail in connection with the assembly process.
The assembly of the three-dimensional double-spiral heater is characterized in that a heating wire is firstly connected with a leading-out wire, the heating wire is wound on the leading-out wire for five turns, then the heating wire is wound on an inner heat-conducting ceramic according to a reserved spiral groove, a wire penetrating hole of an outer heat-conducting ceramic is penetrated when the heating wire reaches the tail end of the inner heat-conducting ceramic, the wire penetrating hole of the inner heat-conducting ceramic and a wire penetrating hole of the outer heat-conducting ceramic are aligned, the heating wire is continuously wound according to the spiral groove on the outer heat-conducting ceramic, and after the heating wire reaches the tail end of the outer heat-conducting ceramic, the heating wire penetrates through the wire penetrating hole of the heat-conducting ceramic and the wire penetrating hole of the inner heat-conducting ceramic and is fixed in a contact manner with a cathode tube, so that the assembly of the heater is completed.
The emitter is installed in the cathode tube, and the emitter and the cathode tube are in interference fit, so that the hot cathode tube and the cold emitter can be used, and the assembly is completed due to expansion caused by heat and contraction caused by cold. The tail part of the air duct is inserted into an air duct hole on the ceramic base from one end of a boss of the ceramic base, so that one end of a fixed shoulder of the air duct, with larger diameter, is abutted against the ceramic base, the cathode tube is welded with the air duct, a heater is assembled on the cathode tube, namely, a central hole of the inner heat conducting ceramic is sleeved on the cathode tube, and meanwhile, an outgoing wire also penetrates through an outgoing wire hole of the ceramic base. Finally, the contact electrode is sleeved on the boss of the ceramic base, the contact electrode fixing hole is aligned with the fixing hole on the boss, and then the contact electrode fixing hole and the fixing hole are fixed by using bolts
The lead is welded on the wiring terminal 19-2 of the wiring piece, and then the wiring piece round hole end 19-2 passes through the bolt for fixing the contact electrode and then passes through the fixing hole of the contact electrode to be fixed on the ceramic base. The cathode tube needs to be grounded, is connected with the air duct, and is welded on the air duct after the cathode is connected with the air duct.
The inner heat-conducting ceramic and the outer heat-conducting ceramic are both made of aluminum oxide ceramic, and boron nitride ceramic or other high-temperature resistant materials can also be selected.
The heating wire adopts tungsten wire, and common heating wire materials such as rhenium tungsten wire or nichrome can also be used.
The conductive wire adopts molybdenum wire, and can also adopt tantalum and other high temperature resistant metal wires.
The contact electrode and the cathode tube are mostly made of tantalum metal or molybdenum metal.
The air duct can be made of stainless steel or other metal materials.
The ceramic base is made of alumina ceramic.
The emitter is made of LaB6, baO-W, C A7 or other emitter materials.
The heater is wound with three layers of heating wires, the length of the heating wires is prolonged, the space utilization rate is improved, meanwhile, more ceramic layers are arranged, higher ignition temperature and self-sustaining discharge stage temperature (the temperature of an emitter material is 1600 ℃ by using LaB6 and 1300 ℃ by using C12A7 and BaO-W) can be met without other heat protection measures, and the induction current of the heater in the ignition moment is zero as a whole by enabling the sum of the number of turns of an inner layer and the number of turns of an outer layer to be equal to the number of turns of a middle layer. The same heating wire is sequentially wound on the inner heat conducting ceramic and the outer heat conducting ceramic, and the heating wire passes through the hole and then contacts with the cathode tube, so that the cathode tube is used as the negative electrode of the heating wire. Multilayer winding heater strip can make heater strip length double promote to bilayer ceramic is compound can promote certain heat preservation ability, is fit for the LaB6 emitter that operating temperature is up to 1600 ℃, and such three-layer complex has effectually utilized the inside space of hollow negative pole, and the heating power on the emitter of unit length promotes to original twice in theory, can reduce heating time to original 1/2.
The emitter is installed in the cathode tube, and the emitter and the cathode tube are in interference fit, so that the hot cathode tube and the cold emitter can be used, and the assembly is completed due to expansion caused by heat and contraction caused by cold. The tail part of the air duct is inserted into an air duct hole on the ceramic base from one end of a boss of the ceramic base, so that one end of a fixed shoulder of the air duct, with larger diameter, is abutted against the ceramic base, the cathode tube is welded with the air duct, a heater is assembled on the cathode tube, namely, a central hole of the inner heat conducting ceramic is sleeved on the cathode tube, and meanwhile, an outgoing wire also penetrates through an outgoing wire hole of the ceramic base. Finally, the contact electrode is sleeved on the boss of the ceramic base, the contact electrode fixing hole is aligned with the fixing hole on the boss, and then the contact electrode fixing hole and the fixing hole are fixed by using bolts
The heater leading-out wire is directly connected with the lead wire to finish the power connection. The lead-out of the contact electrode can be in various forms, and the terminal lug is fixed on one section of the lead, and then one end of a round hole of the terminal lug firstly passes through a bolt for fixing the contact electrode and then passes through a fixing hole of the contact electrode to be fixed on the ceramic base. The cathode tube needs to be grounded, is connected with the air duct, and is welded on the air duct after the cathode is connected with the air duct.
The inner heat-conducting ceramic and the outer heat-conducting ceramic are both made of aluminum oxide ceramic, and boron nitride ceramic or other high-temperature resistant materials can also be selected.
The heating wire adopts tungsten wire, and common heating wire materials such as rhenium tungsten wire or nichrome can also be used.
The conductive wire adopts molybdenum wire, and can also adopt tantalum and other high temperature resistant metal wires.
The contact electrode and the cathode tube are mostly made of tantalum metal or molybdenum metal.
The air duct can be made of stainless steel or other metal materials.
The ceramic base is made of alumina ceramic.
The emitter is made of LaB6, baO-W, C A7 or other emitter materials.
The wiring lug is made of copper material
The hollow cathode can be ignited after being assembled and connected, and the hollow cathode needs to work under the vacuum condition, working medium, generally xenon, is firstly introduced into the hollow cathode through an air duct, the flow is 7sccm, the hollow cathode is ventilated for 5 minutes to remove residual gas in the pipe, then a heating wire is electrified for heating, the heating time is about 2-4 minutes, and meanwhile, the contact electrode is electrified. Along with the temperature rise of the emitter, the number of heat emission electrons is gradually increased, and finally, discharge can be generated between the touch electrode top and the cathode tube to generate plasma, self-sustaining discharge can be generated in the plasma in the cylinder of the emitter due to the hollow cathode effect, the emitter is heated, at the moment, the heater can be powered off, and the hollow cathode enters a stable self-sustaining discharge stage.
The above embodiments are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solutions of the present invention should fall within the protection scope defined by the claims of the present invention without departing from the design spirit of the present invention.
Claims (10)
1. The utility model provides a long-life quick start hollow cathode with three-dimensional pair of spiral to heater which characterized in that: the hollow cathode consists of a touch electrode, a ceramic base, a cathode tube, a heater, an air duct, a wiring lug and a wire; the touch electrode consists of a touch electrode top and a touch electrode tube body, and is a hollow cathode ignition; the ceramic base is a part made of insulating materials, the center of the ceramic base is a gas guide pipe hole, and a hole slightly smaller than the gas guide pipe hole is a wire leading-out hole; the cathode tube consists of a cathode top and a cathode tube body, the cathode tube is used for conducting air flow, and an emitter is placed; the heater consists of a heating wire, a leading-out wire, inner heat conducting ceramic and outer heat conducting ceramic; the inner heat-conducting ceramic and the outer heat-conducting ceramic are heater main bodies, and adopt an inner-outer double-layer composite mode, and the same heating wire is sequentially wound on the inner heat-conducting ceramic and the outer heat-conducting ceramic from the contact position of the same heating wire and the leading-out wire; the winding rotation direction of the inner heat-conducting ceramic is the same as that of the outer heat-conducting ceramic; the air duct is a metal pipe with a shoulder part; the connection lug is a part for connecting the hollow cathode with an external power supply.
2. A long life fast start hollow cathode with a three-dimensional dual spin heater as set forth in claim 1 wherein: the outer heat-conducting ceramic is provided with two wire penetrating holes, the initial wire penetrating hole at one end is the starting point of winding the heating wire on the outer heat-conducting ceramic, the other end is the end point of the heating wire, the heating wire passes through the wire penetrating hole and then continuously passes through the wire penetrating hole of the inner heat-conducting ceramic to be contacted with the cathode tube, a closed loop is formed, and the cathode tube is used as the negative electrode of the heating wire.
3. A long life fast start hollow cathode with a three-dimensional dual spin heater as set forth in claim 1 or 2, wherein: the inner heat-conducting ceramic is provided with an inner heat-conducting ceramic threading hole and an inner heat-conducting ceramic spiral groove, the total length of the inner heat-conducting ceramic is equal to that of the outer heat-conducting ceramic, and the axes of the outer heat-conducting ceramic termination threading hole and the inner heat-conducting ceramic threading hole are coincident to form a through hole.
4. A long life fast start hollow cathode with a three-dimensional dual spin heater as set forth in claim 1 wherein: the diameter of the ceramic base is not smaller than the outer diameter of the contact electrode, a section of boss with a smaller diameter is arranged on the ceramic base, the diameter of the boss is the same as the inner diameter of the contact electrode, four threaded holes are formed in the periphery of the boss and are used for being matched with the four fixing holes on the contact electrode, and the contact electrode is fixed.
5. A long life fast start hollow cathode with a three-dimensional dual spin heater as set forth in claim 1 wherein: the air duct connecting ring is a region connected with the cathode tube, the outer diameter of the air duct connecting ring is equal to the inner diameter of the cathode tube, and the air duct connecting ring is sleeved on the cathode tube and then is connected with the cathode tube by welding; the small end of the shoulder part of the air guide tube is equal to the outer diameter of the cathode tube, the diameter of the large end of the air guide tube is at least 1mm larger than that of the small end of the air guide tube, and the tail part of the air guide tube is used for air supply.
6. A long life fast start hollow cathode with a three-dimensional dual spin heater as set forth in claim 1 wherein: the emitter is arranged in the cathode tube, the two are in interference fit, and the hot cathode tube and the cold emitter are used for completing assembly due to expansion with heat and contraction with cold; the tail part of the air duct is inserted into an air duct hole on the ceramic base from one end of a boss of the ceramic base, so that one end of a fixed shoulder of the air duct with a large diameter is abutted against the ceramic base, the cathode tube is welded with the air duct, a heater is assembled on the cathode tube, namely a central hole of the inner heat conducting ceramic is sleeved on the cathode tube, and meanwhile, an outgoing wire also penetrates through an outgoing wire hole of the ceramic base; and finally, sleeving the contact electrode on a boss of the ceramic base, aligning a contact electrode fixing hole with a fixing hole on the boss, and fixing the contact electrode and the boss by using a bolt.
7. A long life fast start hollow cathode with a three-dimensional dual spin heater as set forth in claim 1 or 4, wherein: the contact electrode is led out and needs to be welded on the wiring end of the wiring lug, then the round hole end of the wiring lug firstly passes through the bolt for fixing the contact electrode and then passes through the fixing hole of the contact electrode to be fixed on the ceramic base; the cathode tube needs to be grounded, is connected with the air duct, and is welded on the air duct after the cathode is connected with the air duct.
8. A long life fast start hollow cathode with a three-dimensional dual spin heater as set forth in claim 1 or 6, wherein: the heater leading-out wire is directly connected with the lead wire to finish the power connection; the wiring piece is fixed on one section of the lead, and then one end of a circular hole of the wiring piece firstly passes through a bolt for fixing the contact electrode and then passes through a fixing hole of the contact electrode to be fixed on the ceramic base.
9. A method for assembling a long life fast start hollow cathode with a three-dimensional dual spin heater according to claim 1, characterized by: the assembly of the three-dimensional double-spiral heater is characterized in that a heating wire is firstly connected with a leading-out wire, the heating wire is wound on the leading-out wire for five turns, then the heating wire is wound on an inner heat-conducting ceramic according to a reserved spiral groove, a wire penetrating hole of an outer heat-conducting ceramic is penetrated when the heating wire reaches the tail end of the inner heat-conducting ceramic, the wire penetrating hole of the inner heat-conducting ceramic and a wire penetrating hole of the outer heat-conducting ceramic are aligned, the heating wire is continuously wound according to the spiral groove on the outer heat-conducting ceramic, and after the heating wire reaches the tail end of the outer heat-conducting ceramic, the heating wire penetrates through the wire penetrating hole of the heat-conducting ceramic and the wire penetrating hole of the inner heat-conducting ceramic and is fixed in a contact manner with a cathode tube, so that the assembly of the heater is completed.
10. The method of assembly of claim 9, wherein: the hollow cathode can be ignited after being assembled and connected, and the hollow cathode needs to work under the vacuum condition, firstly, working medium is introduced into the hollow cathode through an air duct, the flow is 7sccm, the hollow cathode is ventilated for 5 minutes to remove residual gas in the tube, then a heating wire is electrified for heating, the heating time is about 2-4 minutes, and meanwhile, a touch electrode is electrified; along with the temperature rise of the emitter, the number of heat emission electrons is gradually increased, and finally, discharge can be generated between the touch electrode top and the cathode tube to generate plasma, self-sustaining discharge can be generated in the plasma in the cylinder of the emitter due to the hollow cathode effect, the emitter is heated, at the moment, the heater is powered off, and the hollow cathode enters a stable self-sustaining discharge stage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310521750.2A CN116544083A (en) | 2023-05-10 | 2023-05-10 | Long-life quick start hollow cathode with three-dimensional double-rotation heater |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310521750.2A CN116544083A (en) | 2023-05-10 | 2023-05-10 | Long-life quick start hollow cathode with three-dimensional double-rotation heater |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116544083A true CN116544083A (en) | 2023-08-04 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310521750.2A Pending CN116544083A (en) | 2023-05-10 | 2023-05-10 | Long-life quick start hollow cathode with three-dimensional double-rotation heater |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116544083A (en) |
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2023
- 2023-05-10 CN CN202310521750.2A patent/CN116544083A/en active Pending
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