JPH0327324Y2 - - Google Patents

Description

[Detailed description of the invention] (1) Description of the field to which the invention pertains The present invention relates to the improvement of a radiation-cooled multistage collector mainly used in high-power traveling wave tubes mounted on satellites.

(2) Description of conventional technology In high-power traveling wave tubes mounted on satellites, the collector electrode is divided into multiple parts, each with a different A multi-stage collector is generally used that, by applying a voltage, discriminates electrons that have a velocity distribution after interaction with high frequencies according to their respective velocities and captures them while minimizing heat loss. . In addition, since a lot of heat is generated in the collector, in order to prevent the temperature of the satellite body from rising, a traveling wave tube is installed on the satellite with the collector protruding outside the satellite outer wall, and the heat generated in the collector is radiated directly into space. A radiation-cooled collector is used which dissipates the radiation by . Radiation-cooled multistage collectors used in traveling wave tubes mounted on satellites are required to be small, lightweight, and highly reliable against environmental conditions such as vibration and temperature.

FIG. 1 is a cross-sectional view of an example of a conventional radiation-cooled multi-stage collector taken along a plane passing through the central axis. A support plate 2 that supports the collector is brazed to the body 1 (only a portion is shown), and this support plate 2
A stainless steel bellows 3 and a cylindrical thin-walled metal vacuum envelope 4 are brazed to the top, and the vacuum envelope 4 and the dish-shaped thin-walled metal vacuum envelope 5 are arc welded at their respective ribs. to form the vacuum envelope of the collector. Further, a support plate 7 is brazed to the support plate 2 via stainless steel columns 6. The outer periphery of this support plate 7 is brazed to the connection portion between the bellows 3 and the vacuum envelope 4. The first to fourth parts are made of thin metal plates into the required shape.
collector electrodes, respectively 8, 9, 10, 11
are screws 14 set at several locations on the circumference of the support plate 7.
They are held at required intervals with cylindrical porcelain insulating tubes 12 being sandwiched between them as supports. The tip of the screw 14 is tightened with a nut 15 after passing through the support plate 13. The support plate 13 is the vacuum envelope 4
and 5. A central portion of the fourth collector electrode 11 is connected to a central portion of the bottom surface of the vacuum envelope 5 via a ceramic insulating plate 16 .

In such a configuration, lower voltages are applied to the first to fourth collector electrodes in order from the first collector electrode through a power supply line (not shown). Therefore, the electron beam, which has a velocity distribution due to the interaction with the high frequency, enters the first, second, third, and fourth collector electrodes in order from the slowest electrons, and heat loss occurs depending on the velocity when the electrons enter. occurs.
Most of the heat generated in each collector electrode is transferred to the vacuum envelope by conduction through the porcelain insulating tube 12 or the support plates 7 and 13, and further through the porcelain insulating plate 16 as a heat conduction path, and is transferred to the vacuum envelope. Heat is radiated from the surface of the envelope into space by radiation. Heat conduction to the body side is sufficiently suppressed by the stainless steel columns 6 and bellows 3.

In this way, in conventional radiation-cooled multi-stage collectors, most of the heat generated at each collector electrode is transferred to the vacuum envelope by thermal conduction, so the connection between the collector electrode and the porcelain insulating tube is done using screws and nuts. In the conventional mechanically tightened structure, due to the difference in thermal expansion of the components, if the contact condition of the connection becomes poor, heat dissipation will be poor, resulting in an increase in the collector electrode temperature, and as a result, There is a risk that the degree of vacuum inside the tube will deteriorate due to gas discharge from the high temperature section, and this may lead to malfunction. Furthermore, if the contact area of the connecting portion is increased in an attempt to reduce the thermal resistance of the connecting portion, the collector will become larger and its weight will also increase. Furthermore, in order to withstand the severe vibration conditions required for traveling wave tubes onboard satellites, the strength of the structure in which each collector electrode is mechanically tightened and fixed using screws and nuts must be maintained over the operating temperature range of the collector. This has to be maintained by taking into account the difference in thermal expansion between the two, which has the disadvantage of complicating the structure.

(3) Purpose of the invention The purpose of the invention is to provide a radiation-cooled multi-stage collector that eliminates these conventional drawbacks. A metal support with a horseshoe-shaped cross section is brazed to the inner surface of the container and is connected and fixed by brazing through a porcelain insulator, resulting in a radiation-cooled multi-stage collector with a simple structure that has low thermal resistance and vibration resistance. can get. Embodiments of the present invention will be described below based on the drawings.

(4) Explanation of the structure and operation of the invention Figure 2a is a cross-sectional view of a radiation-cooled multi-stage collector to which the invention is applied, taken along a plane passing through the central axis.
Figure b shows a perspective view showing the main parts of the invention. A support plate 2 that supports the collector is brazed to the body 1 (only a portion is shown), a stainless steel bellows 3 and a cylindrical thin-walled metal vacuum envelope 4 are brazed to the support plate 2, and the vacuum An envelope 4 and a dish-shaped vacuum envelope 5 made of thin metal are arc welded at their respective flanges to form the vacuum envelope of the collector. A support plate 7 is brazed to the support plate 2 via stainless steel columns 6. The outer periphery of this support plate 7 is brazed to the connection portion between the bellows 3 and the vacuum envelope 4. Each of the first to fourth collector electrodes 17, 18, 19, 20 made of a thin metal plate into a desired shape has a plurality of radial slits 23 axially symmetrically formed in the outer periphery thereof. The width of the slit and the depth of the slit are determined so as not to greatly disturb the electric field obtained by the voltage applied to the collector electrode. on the other hand,
On the inner surface of the cylindrical thin-walled metal vacuum envelope 4,
A plurality of metal supports 21 each having a horseshoe-shaped cross section are brazed along the outer periphery of each of the collector electrodes 17 to 20. And each collector electrode 17 to 20
is fixed to these metal supports 21 by brazing with a porcelain insulator 22 interposed therebetween. Note that the central portion of the fourth collector electrode 20 is connected to the central portion of the bottom surface of the vacuum envelope 5 via a ceramic insulating plate 16, as in the conventional type.

In such a configuration, part of the heat generated in the first to fourth collector electrodes 17 to 20 is transferred from the high temperature collector electrode to the low temperature collector electrode or from each collector electrode to the vacuum envelope by radiation. 4,
5, most of the heat passes through the porcelain insulator 22 by conduction and is transferred to the metal support 21.
and further transmitted to the vacuum envelopes 4 and 5. Mechanical stress due to differences in thermal expansion of constituent members can be reduced by using slits 23 provided in each collector electrode.
and is reduced by a metal support 21 having a horseshoe-shaped cross section.

(5) Explanation of Effects As explained above, if the radiation-cooled multi-stage collector of the present invention is used, the cross-section of the collector electrode, which has multiple radial slits in the outer circumference, is brazed to the inner surface of the vacuum envelope. On a horseshoe-shaped metal support,
Because it is fixed by brazing through a porcelain insulating stone,
The thermal resistance between the collector electrode and the vacuum envelope can be reduced, and the heat generated at each collector electrode can be transferred to the vacuum envelope with a small temperature difference. As a result, problems such as gas release due to an increase in collector electrode temperature can be avoided. Furthermore, even if the amount of heat generated by the collector changes in response to changes in the operating state of the traveling wave tube, there is almost no mechanical stress on the components of the collector, so stable heat dissipation characteristics can always be obtained. Furthermore, since the configuration is simple, the collector can be made small and lightweight, which is advantageous in terms of vibration resistance.

In the above embodiment, the collector electrodes are arranged in four stages, but it is of course applicable to cases where the number of collector electrodes is different.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional radiation-cooled multistage collector, FIG. 2a is a sectional view of a radiation-cooled multistage collector according to the present invention, and FIG. 2b is a perspective view showing the main parts of the present invention. be. 1...Body, 2, 7, 13...Support plate, 3...
...Bellows, 4,5...Vacuum envelope, 8,9,1
0, 11, 17, 18, 19, 20...1st,
2, 3, 4 collector electrodes, 12... Porcelain insulating tube, 16... Porcelain insulating plate, 22... Porcelain insulator, 14... Screw, 15... Nut, 21... Metal support, 23...Slit.

Claims (1)

[Scope of utility model registration request] A plurality of collector electrodes are arranged at required intervals in the axial direction in a cylindrical metal vacuum envelope, and the heat generated at the collector electrodes is radiated from the metal vacuum envelope to the outside. In the radiation-cooled multi-stage collector, a plurality of slits are provided in the radial direction on the outer periphery of each collector electrode, and a plurality of metal supports each having a horseshoe-shaped cross section are brazed to the inner surface of the metal vacuum envelope. A radiation-cooled multi-stage collector, characterized in that the collector electrode and the metal support are fixed by brazing via a ceramic insulator.