阅读说明：本技术 速调管 (Klystron ) 是由 阿武俊郎 大久保良久 于 2017-12-25 设计创作，主要内容包括：速调管(10)包括电子枪部(A)、多个共振空腔(14a～14j)、收集极(15)以及多根漂移管(16a～16k)。多个共振空腔(14a～14j)包括沿着来自电子枪部(A)的电子(11)的行进方向依次定位的输入空腔(19)、多个中间空腔(21b～21i)以及输出空腔(20)。多个中间空腔(21b～21i)包括多个二次谐波空腔(23d、23g)。收集极(15)对经过多个共振空腔(14a～14j)的电子(11)进行捕捉。多根偏移管(16a～16k)设置在电子枪部(A)与输入空腔(19)之间、多个共振空腔(14a～14j)之间以及输出空腔(20)与收集极(15)之间。(The klystron (10) includes an electron gun section (A), a plurality of resonant cavities (14 a-14 j), a collector (15), and a plurality of drift tubes (16 a-16 k). The plurality of resonant cavities (14 a-14 j) include an input cavity (19), a plurality of intermediate cavities (21 b-21 i), and an output cavity (20) that are positioned in order along the direction of travel of electrons (11) from the electron gun section (A). The plurality of intermediate cavities (21 b-21 i) include a plurality of second harmonic cavities (23d, 23 g). The collector (15) captures electrons (11) that have passed through the plurality of resonant cavities (14 a-14 j). A plurality of offset tubes (16 a-16 k) are provided between the electron gun section (A) and the input cavity (19), between the plurality of resonance cavities (14 a-14 j), and between the output cavity (20) and the collector (15).)

1. A klystron, comprising:

an electron gun part that emits electrons;

a plurality of resonant cavities including an input cavity, a plurality of intermediate cavities, and an output cavity positioned in sequence along a direction of travel of electrons from the electron gun portion, the plurality of intermediate cavities including a plurality of second harmonic cavities;

a collector that captures electrons passing through the plurality of resonant cavities; and

a plurality of drift tubes disposed between the electron gun portion and the input cavity, between the plurality of resonant cavities, and between the output cavity and the collector.

2. A klystron as set forth in claim 1,

the total number of the plurality of resonant cavities is more than ten.

3. A klystron as set forth in claim 1,

the plurality of intermediate cavities are arranged along a traveling direction of electrons,

two or more intermediate cavities are provided between the second harmonic cavity located on the upstream side and the second harmonic cavity located on the downstream side in the traveling direction of electrons,

a plurality of intermediate cavities of the plurality of intermediate cavities other than the plurality of second harmonic cavities includes the two or more intermediate cavities.

4. A klystron as set forth in claim 1,

the diameter of the drift tube adjacent to the second harmonic cavity is equal to or less than half of the diameter of the second harmonic TE11 mode, at which the electromagnetic wave has a cutoff frequency.

5. The klystron of any one of claims 1 to 4,

each of the plurality of resonant cavities has a gap in communication with the interior of the drift tube,

the interval between the centers of the gaps of a pair of adjacent resonant cavities in the plurality of resonant cavities is 0.05-0.08 times of the plasma wavelength of the electrons.

6. A klystron as set forth in claim 1,

setting the total number of the plurality of resonant cavities to n,

counting from the side close to the electron gun part,

setting the diameter of the drift tube between the n-th resonance cavity and the n-1 st resonance cavity as D_n，

Setting the diameter of the drift tube between the n-1 th resonance cavity and the n-2 nd resonance cavity as D_n-1，

Setting the diameter of the drift tube between the n-2 th resonance cavity and the n-3 rd resonance cavity as D_n-2，

Setting the diameter of the offset tube between the n-th resonant cavity and the collector to D_c，

Satisfies the following conditions: d_n-2＜D_n-1＜D_n＜D_c。

7. The klystron of any one of claims 1 to 6,

the output cavity is composed of three or more cavity units electrically coupled to each other through a diaphragm provided in a longitudinal direction of the drift tube or a coupling hole provided in a wall surface of the cavity unit.

8. A klystron as set forth in claim 7,

the total number of the cavity units is three.

Technical Field

Embodiments of the present invention relate to a klystron.

Background

A klystron is an electron tube for amplifying high-frequency power, and includes an electron gun portion for emitting electrons, an input portion and an output portion for high-frequency power, a harmonic interaction portion, and a collector for capturing used electrons. The harmonic wave interaction portion is composed of a plurality of resonant cavities arranged in the traveling direction of electrons. The resonant cavity includes an input cavity to which the high-frequency power is input, an output cavity to which the high-frequency power is output, and a plurality of intermediate cavities between the input cavity and the output cavity. The electron gun part and the harmonic interaction part, the plurality of resonance cavities constituting the harmonic interaction part, and the harmonic interaction part and the collector part are connected by drift tubes, respectively.

In the klystron having the above-described configuration, electrons emitted from the electron gun portion pass through the input cavity and are clustered by interacting with the plurality of intermediate cavities located in front of the input cavity. The kinetic energy of the clustered electrons is applied to the high-frequency wave input from the input cavity, so that the clustered electrons are decelerated at the output cavity, thereby being extracted from the output portion as high-frequency power amplified to a target output.

In addition, in order to improve the electron clustering effect and increase the efficiency, a klystron is provided in which one of a plurality of intermediate cavities is used as a second harmonic cavity.

However, there are technical problems in the klystron as follows: the clustered electrons are easily repelled from each other by space charges and thus easily diffused in the traveling direction, and further, because there is a difference in the velocity of the electrons, the electrons cannot be uniformly decelerated at the input cavity, and the conversion efficiency into high-frequency power is difficult to improve.

Disclosure of Invention

Technical problem to be solved by the invention

The invention provides a klystron which improves the conversion efficiency of converting to high-frequency power.

Technical scheme for solving technical problem

The klystron of an embodiment includes:

an electron gun part that emits electrons;

a plurality of resonant cavities including an input cavity, a plurality of intermediate cavities, and an output cavity positioned in sequence along a direction of travel of electrons from the electron gun portion, the plurality of intermediate cavities including a plurality of second harmonic cavities;

a collector that captures electrons passing through the plurality of resonant cavities; and

a plurality of drift tubes disposed between the electron gun portion and the input cavity, between the plurality of resonant cavities, and between the output cavity and the collector.

Drawings

Fig. 1 is a sectional view showing the structure of a klystron according to a first embodiment.

Fig. 2 is a cross-sectional view showing a part of the tube container of the klystron shown in fig. 1, and shows a second harmonic cavity and the like.

Fig. 3 is a cross-sectional view showing a part of the tube container of the klystron shown in fig. 1, and is a view for explaining the intervals of the resonant cavities.

Fig. 4 is a sectional view showing a tube container and a collector of a klystron of the second embodiment, and is a view for explaining the diameter of a drift tube.

Fig. 5 is a sectional view showing a tube container and a collector of a klystron according to a third embodiment, and shows a cavity unit and the like.

Fig. 6 is a sectional view showing a tube container and a collector of a klystron according to a fourth embodiment, and shows a cavity unit and the like.

Detailed Description

Hereinafter, a first embodiment will be described with reference to fig. 1 to 3.

Fig. 1 is a sectional view showing a schematic structure of a klystron 10. As shown in fig. 1, the klystron 10 includes an electron gun portion a that emits electrons 11. The electron gun section a includes a cathode 12a for generating the electrons 11, an anode 12b for accelerating the electrons 11, and the like.

A harmonic interaction part B is provided in the traveling direction of the electrons 11, i.e., in front of the electron gun part a. The harmonic interaction portion B includes a tubular tube container 13 and a plurality of resonant cavities 14, wherein the resonant cavities 14 are formed in the tube container 13 and are aligned along the traveling direction of the electrons 11. The harmonic wave interaction portion B includes, for example, ten resonant cavities 14a to 14 j.

A collector 15 is provided further forward of the harmonic interaction portion B in the traveling direction of the electrons 11, and the collector 15 captures the electrons 11 having passed through the harmonic interaction portion B (the resonant cavities 14a to 14 j).

The electron gun section a and the harmonic interaction section B, the plurality of resonant cavities 14a to 14j, and the harmonic interaction section B and the collector 15 are connected by drift tubes 16a to 16k, respectively. The tube container 13 constituting the resonant cavities 14a to 14j and the drift tubes 16a to 16k is formed of, for example, copper.

Further, of the plurality of resonant cavities 14a to 14j constituting the harmonic interaction portion B, an input portion 17 for inputting high-frequency power is connected to the resonant cavity 14a located on the electron gun portion a side, and an output portion 18 for outputting high-frequency power is connected to the resonant cavity 14j located on the collector 15 side. For example, the input unit 17 is a coaxial line, and the output unit 18 is a waveguide.

Of the plurality of resonant cavities 14a to 14j constituting the high-frequency interaction portion B, the resonant cavity 14a located on the electron gun portion a side is an input cavity 19, the resonant cavity 14j located on the collector 15 side is an output cavity 20, and the plurality of resonant cavities 14B to 14i located between the input cavity 19 and the output cavity 20 are intermediate cavities 21B to 21 i.

According to the above description, the drift tube 16a is provided between the electron gun section a and the input cavity 19. The drift tube 16k is disposed between the output cavity 20 and the collector 15. The drift tubes 16b to 16j are respectively provided between a pair of adjacent resonance cavities among the plurality of resonance cavities 14a to 14 j.

The intermediate cavities 21b to 21i include a plurality of fundamental wave cavities 22b, 22c, 22e, 22f, 22h, 22i and a plurality of second harmonic cavities 23d, 23 g. The plurality of second harmonic cavities 23d and 23g are provided at arbitrary positions among the intermediate cavities 21b to 21 i. The second harmonic cavity 23d on the electron gun section a side is separated from the input cavity 19 by a plurality of fundamental wave cavities 22b and 22c, the second harmonic cavity 23g on the collector 15 side is separated from the output cavity 20 by a plurality of fundamental wave cavities 22h and 22i, and the second harmonic cavities 23d and 23g are separated by a plurality of fundamental wave cavities 22e and 22 f.

In the present embodiment, the following case is shown: the number of resonant cavities 14a to 14j is ten, the number of intermediate cavities 21b to 21i is eight, and the number of second harmonic cavities 23d and 23g is two. In this case, the second harmonic cavities 23d and 23g are provided at every two positions of the intermediate cavities 21b to 21i with respect to the traveling direction of the electrons 11. Thus, the intermediate cavities 21b, 21c, 21e, 21f, 21h, 21i are fundamental wave cavities 22b, 22c, 22e, 22f, 22h, 22i, and the intermediate cavities 21d, 21g are second harmonic cavities 23d, 23 g.

Fig. 2 is a sectional view showing a part of the tube container 13 of the klystron 10, and is a view showing the second harmonic cavities 23d, 23g, and the like. As shown in fig. 2, the second harmonic cavities 23d, 23g are formed in a smaller shape than the intermediate cavities 21b, 21c, 21e, 21f, 21h, 21i other than the second harmonic cavities 23d, 23g, that is, the fundamental wave cavities 22b, 22c, 22e, 22f, 22h, 22 i. That is, the second harmonic cavities 23d and 23g have smaller outer diameters OD, narrower widths in the electron traveling direction, smaller cavity volumes, and smaller opening widths of the gaps (openings) 24 communicating with the inside of the drift tubes 16a to 16k than the fundamental wave cavities 22b, 22c, 22e, 22f, 22h, and 22 i.

Fig. 3 is a cross-sectional view showing a part of the tube container 13 of the klystron 10, and is a view for explaining the intervals of the resonant cavities 14a to 14 j. In fig. 3, the relationship between the resonant cavities 14e and 14f is shown as a representative of the resonant cavities 14a to 14j, and the same applies to the relationship between the other resonant cavities 14a to 14e and 14f to 14 j. As shown in fig. 3, the resonant cavities 14e and 14f (14a to 14j) have gaps 24 communicating with the inside of the drift tubes 16e to 16g (16b to 16 j). The interval L between the centers of the gaps 24 of the resonant cavities 14e and 14f (14a to 14j) adjacent to each other with the drift tube 16f (16b to 16j) therebetween is the interval between the resonant cavities 14e and 14f (the interval between the adjacent pair of resonant cavities 14 of the resonant cavities 14a to 14 j). When the sparse wave of the concentrated electrons 11 propagates in the traveling direction, the interval L is preferably set to 0.05 to 0.08 times the reduced plasma wavelength (japanese: low or low プラズマ wavelength) indicating the wavelength of the sparse wave.

As shown in fig. 1, in the klystron 10 configured as described above, the electrons 11 emitted from the electron gun portion a pass through the resonant cavity 14a (input cavity 19) of the output portion 17 having high-frequency power, which is located on the electron gun portion a side, and are clustered by interacting with the plurality of resonant cavities 14b to 14j (the plurality of intermediate cavities 21b to 21i and the output cavity 20) located in front of the resonant cavity. The clustered electrons 11 are decelerated at the resonance cavity 14j (output cavity 20) located on the collector 15 side, and are extracted from the output portion 18 as high-frequency power amplified to a target output.

When the electrons 11 are clustered by the interaction between the electrons 11 and the plurality of resonant cavities 14b to 14j, since the plurality of second harmonic cavities 23d and 23g are included in the plurality of resonant cavities 14b to 14j (the plurality of intermediate cavities 21b to 21i), the second harmonic waves generated in the second harmonic cavities 23d and 23g are superimposed on the fundamental wave, thereby enhancing the clustering effect of the electrons 11.

Here, in the case of, for example, grouping electrons using five resonant cavities, since the degree of grouping of electrons at each resonant cavity is large, the grouped electrons are repelled by space charges, and the electrons are easily diffused in the traveling direction thereof, and further, since there is a difference in the velocity of the electrons, the electrons cannot be uniformly decelerated at the resonant cavity (output cavity) connected to the output portion, and it is difficult to improve the conversion efficiency into high-frequency power.

In contrast, in the present embodiment, the electrons 11 can be gradually clustered by, for example, ten resonance cavities 14a to 14 j. This suppresses the diffusion of the clustered electrons 11 in the traveling direction thereof, thereby making the speed uniform and improving the conversion efficiency into high-frequency power. In order to gradually cluster the electrons 11, the total number of the resonant cavities 14a to 14j is preferably ten or more.

Further, by using, for example, the ten resonant cavities 14a to 14j, the intermediate cavities 21b to 21i can include the plurality of second- harmonic cavities 23d and 23g, and therefore, the effect of bunching the electrons 11 can be further improved. In addition, the use of the plurality of second harmonic cavities 23d and 23g can shorten the entire length of the klystron 10.

The plurality of intermediate cavities 21b to 21i are arranged along the traveling direction of the electrons 11. Two or more intermediate cavities 21 are provided between the second harmonic cavity 23 located on the upstream side and the second harmonic cavity 23 located on the downstream side in the traveling direction of the electrons 11. The plurality of intermediate cavities 21 (fundamental wave cavities 22) other than the plurality of second harmonic cavities 23 among the plurality of intermediate cavities 21b to 21i include the two or more intermediate cavities 21.

In the present embodiment, of the positions of the intermediate cavities 21b to 21i, the second harmonic cavity 23d located on the upstream side in the traveling direction of the electron 11 and the second harmonic cavity 23g located on the downstream side are provided with the second harmonic cavities 23d and 23g at positions separated by the intermediate cavities 21e and 21f, respectively. This can further improve the effect of clustering the electrons 11.

By providing the second harmonic cavities 23d and 23g at every other plurality of positions of the intermediate cavities 21b to 21i with respect to the traveling direction of the electrons 11, the plurality of second harmonic cavities 23d and 23g can be arranged at equal intervals among the plurality of intermediate cavities 21b to 21i, and the clustering effect of the electrons 11 can be further improved.

As shown in fig. 1 and 2, in order to prevent the second harmonics generated in the second harmonic cavities 23D and 23g from being electrically coupled to the other resonance cavities 14a to 14c, 14e, 14f, and 14h to 14j, it is preferable that the diameter (inner diameter) D of the drift tubes 16D, 16e, 16g, and 16h adjacent to the second harmonic cavities 23D and 23g is equal to or less than half of the diameter (inner diameter) of the second harmonic in the TE11 mode, which is the cutoff frequency.

As shown in fig. 1 and 3, when the dilatational wave of the bunched electrons 11 propagates in the traveling direction, the arrangement of the resonant cavities 14a to 14j can be optimized by setting the interval L between the centers of the gaps 24 of the resonant cavities 14a to 14j adjacent to each other with the drift tubes 16b to 16j interposed therebetween to 0.05 to 0.08 times the reduced plasma wavelength representing the wavelength of the dilatational wave.

It is arbitrary which of the resonant cavities 14a to 14j is the second harmonic cavity 23, and three or more may be used as the second harmonic cavities 23. When the plurality of intermediate cavities 21 include three or more second harmonic cavities 23, it is preferable that two or more intermediate cavities 21 (fundamental wave cavities 22) are provided between a pair of adjacent second harmonic cavities 23.

Next, referring to fig. 4, the klystron 10 of the second embodiment will be described. The same reference numerals are given to the same components as those of the first embodiment, and the description of the components and their operational effects will be omitted.

Fig. 4 is a sectional view showing the tube container 13 and the collector 15 of the klystron 10 of the second embodiment, and is a view for explaining the diameters of the drift tubes 16h to 16 k.

As shown in FIG. 4, the total number of resonant cavities 14a to 14j is n, and the diameter D of a drift tube 16j located between an nth resonant cavity 14j and an n-1 st resonant cavity 14i as counted from the side close to the electron gun section A_nA diameter D of a drift tube 16i between the n-1 st resonant cavity 14i and the n-2 nd resonant cavity 14h_n-1A diameter D of a drift tube 16h between the n-2 nd resonant cavity 14h and the n-3 rd resonant cavity 14g_n-2And the diameter D of the drift tube 16k between the nth resonant cavity 14j and the collector 15_cSatisfies the following formula (1).

D_n-2＜D_n-1＜D_n＜D_c… … type (1)

For example, if the diameters of the offset pipes 16h to 16k are D₈、D₉、D₁₀、D_cAccording to formula (1), having D₈＜D₉＜D₁₀＜D_cThis relationship.

Furthermore, the drift tubes 16h to 16k satisfying the formula (1) can gradually diffuse the clustered electrons 11 in the diameter direction of the drift tubes 16h to 16k, and can suppress the diffusion of the electrons 11 in the traveling direction due to repulsion of space charges, so that the conversion efficiency into high-frequency power can be easily improved.

The drift tube 16 is not limited to the drift tubes 16h to 16k located on the collector 15 side, and the diameter of any number of the drift tubes 16a to 16k may be gradually increased toward the collector 15 side.

Next, referring to fig. 5, the klystron 10 of the third embodiment will be described. The same reference numerals are given to the same components as those in the embodiments, and the description of the components and their operational effects will be omitted.

Fig. 5 is a sectional view showing the tube container 13 and the collector 15 of the klystron 10 of the third embodiment, and is a view showing the cavity units 25a to 25c and the like.

As shown in fig. 5, the output cavity 20, i.e., the resonant cavity 14j has three or more cavity units 25. In the present embodiment, the output cavity 20 has three cavity units 25a to 25 c. The cavity cells 25a to 25c are electrically coupled by diaphragms 26a and 26b provided along the tube axis of the klystron 10.

Further, by using the cavity cells 25a to 25c electrically coupled to each other as the resonant cavity 14j, the electrical coupling between the resonant cavity 14j and the electrons 11 can be improved, and therefore, the conversion efficiency into high-frequency power can be easily improved.

Next, referring to fig. 6, the klystron 10 of the fourth embodiment will be described. The same reference numerals are given to the same components as those in the embodiments, and the description of the components and their operational effects will be omitted.

Fig. 6 is a cross-sectional view showing the tube container 13 and the collector 15 of the klystron 10 according to the fourth embodiment, and is a view showing the cavity units 25a to 25c and the like.

As shown in fig. 6, the cavity units 25a to 25c are electrically coupled through coupling holes 27a, 27b provided in the wall surfaces of the cavity units 25a to 25 c. The shape of the coupling holes 27a and 27b is arbitrary.

Further, the cavity cells 25a to 25c electrically coupled to each other can be used as the resonant cavity 14j (output cavity 20). In this case, the electric coupling between the resonance cavity 14j and the electron 11 can be improved, and therefore, the conversion efficiency into high-frequency power can be easily improved.

According to at least one embodiment described above, diffusion of the electrons 11 clustered by the resonant cavities 14a to 14j in the traveling direction is suppressed, the speed is uniform, and the conversion efficiency into high-frequency power can be improved by the klystron 10.

While the embodiments of the present invention have been described above, the embodiments are merely examples and do not limit the scope of the present invention. These new embodiments may be implemented in other various ways, and various omissions, substitutions, and changes may be made without departing from the scope of the technical idea of the present invention. These embodiments and modifications thereof are included in the scope or gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.