JPS624814B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides a multi-stage collector type electron beam tube in which the collector is configured in multiple stages in order to improve efficiency in an electron beam tube having a collector that ultimately captures the electron beam that has contributed to the amplification effect. Regarding pipes.

In an electron beam tube such as a traveling wave tube, an electron beam emitted from an electron gun undergoes high frequency amplification in a high frequency circuit section and is then captured by a collector. At this time, the efficiency of the electron beam tube increases if the electron beam reaches the collector in a state in which the energy of collision with the collector is reduced.
In order to improve efficiency, a method has generally been used in which the collector voltage is lowered than the high frequency circuit voltage. However, since there are variations in the speed of the electron beams involved in the high-frequency amplification effect, in order to capture electron beams with these variations in speed with a single collector, it is necessary to apply a voltage that allows the slowest electrons to reach the collector. collector voltage, making it difficult to significantly improve efficiency. For this reason, various electron beam tubes in which the collector is divided into a plurality of pieces have been considered in order to further improve efficiency.
It is true that if the number of collector divisions is increased and voltages that are sequentially lower than the high-frequency circuit voltage are applied to each collector individually as the distance from the high-frequency circuit increases, the electron beams involved in the high-frequency amplification effect will be speed-sorted by the collector. be captured. That is, a slow electron beam is captured by a collector with a high potential, and a fast electron beam is captured by a collector with a low potential, improving efficiency. However, in order to divide the collector into multiple pieces, it is necessary to electrically insulate each collector, and in order to cool each collector, a heat sink is installed on the outer periphery of each collector, which is electrically insulated from the ground point. It was necessary to attach the collector part, which complicated the structure of the collector part, and there were drawbacks such as an increase in the size and weight of the collector part including the heat sink. Furthermore, in order to cool the individual collectors, it is difficult to provide sufficient electrical insulation between the collectors or between each collector and the ground point. In particular, when the collector is divided into three or more stages, the above-mentioned drawbacks become noticeable.

The present invention has a collector divided into a plurality of pieces,
In an electron beam tube where multiple collectors are electrically insulated from the ground point, the heat generated in the collector is effectively transferred to the outside with a simple structure without increasing the vacuum sealing surface of the collector part. The object of the present invention is to provide a multi-stage collector type electron beam tube in which a sufficient cooling effect can be obtained and, in addition, the collector can be easily electrically insulated from a ground point.

The present invention includes an electron gun that generates an electron beam, a high-frequency circuit section that performs high-frequency interaction, a magnetic field focusing device that focuses the electron beam, and a collector that captures the interacted electron beam. In a multi-stage collector type electron beam tube, the collector is composed of a plurality of collectors,
One end of the cylindrical ceramic, which will become part of the vacuum envelope, is fixed to the output end of the high-frequency circuit section by brazing, etc., and multiple collectors are coaxially aligned in the axial direction so as to contact the inner surface of the cylindrical ceramic. The other end of the cylindrical ceramic was vacuum-sealed with a ceramic plate or a metal plate, and the voltage applied to each collector was projected through a plurality of holes drilled in the side of the cylindrical ceramic. It is characterized in that it is supplied through a collector lead.

Next, the present invention will be explained in detail with reference to the drawings. 1a and 1b show a traveling wave tube having a three-stage collector embodying the present invention, which consists of an electron gun 1, a high frequency circuit section (slow wave circuit) 2, a high frequency input section 3, a high frequency output 4, a magnetic field focusing device 5, a collector 10, a heat radiator 17, etc., and the electron gun side is placed and fixed on a holding plate 6 via a support 18. However, the collector 10 is arranged on the inner circumferential surface of the cylindrical ceramic 11 in a state where the first collector 7, the second collector 8, and the third collector 9 are distributed at intervals in the axial direction. Cylindrical ceramic 11
The inside of the is stepped, and the first to third collectors 7, 8, and 9 are inserted so as to butt against the steps to perform axial positioning, and the collectors 7, 8, and 9 are electrically connected to each other. insulated. The cylindrical ceramic 11 is made of beryllia, ceramic, or alumina ceramic, which has a high thermal conductivity among insulating stones and is dense. Both end faces of the cylindrical ceramic 11 are metallized, and one end is rolled onto the end face of the high frequency circuit section 2. The ceramic wave 12 is fixed by brazing on the opposite end face and vacuum sealed. Further, a small hole 13 with a diameter of about 1 mm is pre-drilled on the side surface of the cylindrical ceramic 11 for taking out the collector lead, and this hole 13 is metallized. Collector leads 14, 15, 16 are holes 1
The three parts are each fixed by brazing, and a voltage is applied to the first to third collectors 7, 8, 9 via collector leads 14, 15, 16. The material used for the collector 10 is copper, molybdenum, nickel, or the like, which has good thermal conductivity and a high melting point temperature. 1st
- In order to improve the contact between the outer surfaces of the third collectors 7, 8, and 9 and the inner surface of the cylindrical ceramic 11,
Outer diameter of collectors 7, 8, 9 and cylindrical ceramic 11
The inner diameter of the cylindrical ceramic 11 may be made approximately equal to improve the fitting, but slots extending in the longitudinal direction may be provided on the side surfaces of the first to third collectors 7, 8, and 9 so that the inner diameter of the collector 7 is approximately equal to the inner diameter of the cylindrical ceramic 11. , 8, 9 by increasing their outer diameters and applying mechanical force in the axial direction to insert the collectors 7, 8, 9 into the cylindrical ceramic 11.
The contact between the collector 10 and the cylindrical ceramic 11 is further improved, and the collectors 7, 8, 9 are stably held and fixed. In addition, the first to third collectors 7, 8,
If the inner surface of the cylindrical ceramic 11 in contact with the cylindrical ceramic 11 is locally metallized in advance, the cylindrical ceramic 11 and the first to third collectors 7, 8, 9
It can also be held and fixed by brazing. In such a traveling wave tube, the electron beam emitted from the electron gun 1 is focused by the magnetic field focusing device 5,
It passes through the central axis of the high frequency circuit section 2, during which an amplification effect is performed by interaction with the high frequency applied from the high frequency input section 3, and a high frequency output is taken out from the high frequency output section 4. Since the speed of the electron beam that has undergone high-frequency amplification varies, the electron beam is captured by one of the first to third collectors 7, 8, and 9, each having a different potential, depending on the speed of the electron beam. Ru. In this case, the heat generated in the first to third collectors 7, 8, 9 is transferred to the cylindrical ceramic 11 and the heat sink 17, thereby cooling the collectors 7, 8, 9. With this structure, the first to
Since the heat generated in the third collectors 7, 8, 9 is transferred to the heat radiator 17 via the cylindrical ceramic 11, a heat radiator is directly attached to each of the first to third collectors 7, 8, 9. , 8, and 9, and regardless of the number of collector divisions, there is only one heat conduction path leading to the heat sink 17 leading to the heat flow field (retaining plate 6), and the collector structure is simplified. At the same time, it is extremely advantageous for reducing the size and weight of the collector section. Further, the first to third collectors 7, 8, 9 are not exposed on the outer surface and can be sufficiently electrically insulated from the ground point by the cylindrical ceramic 11. Thermal resistance between the first to third collectors 7, 8, 9 and the heat sink 17 is determined by the thermal conductivity and dimensions of the cylindrical ceramic 11, and the electric power consumed by the first to third collectors 7, 8, 9 and By selecting the dimensions of the cylindrical ceramic 11 in consideration of the allowable collector temperature, the cylindrical ceramic 11 can sufficiently serve as a heat conduction path. By interposing a highly conductive adhesive at the contact portion between the heat sink 17 and the cylindrical ceramic 11, it is possible to improve the thermal resistance between the heat sink and the cylindrical ceramic 11.

FIGS. 2a and 2b show another embodiment of the electron beam tube according to the present invention, in which the same or corresponding parts as in FIGS. 1a and 1b are given the same numbers. In FIG. 2a, the inner diameter of the cylindrical ceramic 11 does not have a stepped shape and is uniformly almost constant, and the cylindrical ceramic 11 is fixed to the end face of the high frequency circuit section 2 by brazing, and The tube 19 is connected between the end of the high frequency circuit section 2 and the first collector, and between the first to third collectors 7,
It is interposed between collectors 8 and 9.

A ceramic plate 12 is fixed to the other end of the cylindrical ceramic 11 by brazing so as to fit the bottom of the third collector 9 and vacuum-sealed. On the outer periphery of the cylindrical ceramic 11, a vaned heat sink 20 with grooves 21 is arranged. The collector leads 14, 15, and 16 are taken out from the cutout groove 21, and a lead for high voltage application (not shown) is connected to the cutout groove 21 by soldering or the like. is filled. According to the embodiments of FIGS. 2a and 2b, FIGS.
Compared to the embodiment b, the mutual positions of the first to third collectors 7, 8, 9 in the axial direction are determined by the dimensions of the insulating porcelain cylinder 19, and the cylindrical ceramic 11 and the first to third collectors 7, 8 , 9 are not firmly held and fixed by brazing or the like, the first to third collectors 7,
8 and 9 can be held and fixed at predetermined positions inside the cylindrical ceramic 11. Therefore, by adjusting the length of the insulated magnetic cylinder 19, the axial position between the collectors can be adjusted.
It is also possible to select pyrolytic graphite (pyrolytic graphite), which is made by decomposing a carbon compound with a high permissible temperature, as the material for 0. Further, the bladed heat dissipating body 19 is surrounded over the entire outer circumference of the cylindrical ceramic 11.
The heat dissipation effect from 1 is improved, which is advantageous for cooling the collector.

In the above embodiments, a traveling wave tube in which the collector is divided into three stages is used as the electron beam tube, but the present invention is not limited to this. Of course, it can be applied to electron beam tubes such as trunk klystrons.

As described above, according to the present invention, regardless of the number of collector divisions, heat generated in the collector can be absorbed without deteriorating the electrical insulation between each collector and the ground point.
In addition, the vacuum can be effectively transmitted to the outside without increasing the vacuum sealing surface of the collector section, and even if the collector is divided for the purpose of improving efficiency, it is possible to prevent the collector section from increasing in size and weight. becomes possible. In particular, great effects can be obtained when the present invention is applied to an electron beam tube in which the collector is divided into three to five stages or more.

[Brief explanation of the drawing]

FIG. 1a is an axial sectional view showing an example of a multi-stage collector type electron beam tube according to the present invention, FIG. 1b is a side view similarly seen from the collector side, and FIGS. 2a and b are other embodiments of the present invention. FIG. 2 is an axial cross-sectional view and a side view showing a collector portion of the present invention. 1... Electron gun, 2... High frequency circuit section (slow wave circuit), 3... High frequency input section, 4... High frequency output section, 5... Magnetic focusing device, 6... Holding plate, 7,
8, 9...first, second, third collector...10...
collectors, including first, second, and third collectors; 1;
1... Cylindrical ceramic, 12... Ceramic plate,
13... Hole drilled in the side of the cylindrical ceramic 11, 14, 15, 16... Collector lead, 17
...Heat radiator, 18... Support stand, 19... Insulated porcelain tube, 20... Heat radiator with vanes, 21... Notch groove.

Claims (1)

[Claims] 1. In a multistage collector type electron beam tube consisting of multiple collectors, one end of the cylindrical ceramic that will become part of the vacuum envelope is fixed to the output side end of the high frequency circuit section by brazing, etc., and the inner surface of the cylindrical ceramic is A plurality of collectors are coaxially arranged at intervals in the axial direction so as to be in contact with each other, the other end of the cylindrical ceramic is vacuum-sealed, and the voltage applied to each collector is applied to the side of the cylindrical ceramic. A multi-stage collector type electron beam tube characterized in that the electron beam tube is supplied with a collector lead protruding through a plurality of holes.