JPH0210633A - Microwave tube - Google Patents

Abstract

PURPOSE:To simplify the structure and relatively optionally set the Q value by providing an inside cavity wall on the inside of the airtight seal outer periphery wall of a resonance cavity and boring at least one Q adjusting through hole or recess. CONSTITUTION:As an example applicable to the fundamental harmonic cavity of a multi-cavity klystron, multiple resonance cavities 1 are connected with a drift tube 2, an inside cavity wall 4 is provided on the inside of the airtight seal outer periphery wall 3 of the resonance cavities 1, the cavity inside this cavity wall 4 forms an electric cavity. At least one Q adjusting through hole 5 to adjust Q to the proper value is bored on the cavity wall 4, the resonance cavities 1 and the outside space S become a vacuum area via this through hole 5. In this case, if the number of the through hole 5 and the value of Q are experimentally determined once, the number of the through hole 5 corresponding to the value of Q to be determined can be correctly obtained, the number of components is reduced, and manufacture is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) This invention relates to microwave tubes such as multi-cavity klystrons and accelerators, and particularly to improvements in their resonant cavities.

(Prior Art) For example, a beam straight-travel type multi-cavity klystron has a plurality of resonant cavities connected between an electron gun and a collector by a drift tube. When the output of such a multi-cavity klystron is relatively small, there are two types of cavities: one is a so-called external cavity type, which is made of cylindrical ceramic to keep it vacuum-tight, and has a removable cavity attached to the outside. The shell itself maintains vacuum tightness and can be classified as a built-in cavity type. When the output of the klystron is approximately several tens of kilowatts or more, the ceramic generates a significant amount of heat, so a built-in cavity type is usually used. Also, in this type, the Q of the cavity is very high, so the band as a klystron is very narrow.

Therefore, in the past, a coupling loop was attached to the cavity and a load was further connected to it to lower the Q of the cavity as a whole and widen the band characteristics of the klystron. In this case, in order to attach the coupling loop, this part must be provided with electrically insulating and vacuum-tight ceramic. And since the externally connected load is usually of the coaxial type, the vacuum-tight ceramic must also be vacuum-tight on both the inner and outer shafts.

(Problems to be Solved by the Invention) The conventional techniques described above have the following disadvantages.

The ceramic must be vacuum tight in both the inner sleeve and outer ring as described above. Therefore, the structure becomes complicated, the possibility of leakage increases, and the number of parts increases.

Furthermore, the assembly process becomes longer. Furthermore, if a leak were to occur in this part, most of the parts would have to be thrown away, resulting in a large loss.

Furthermore, delays occur in the process, making it impossible to supply products in a timely manner.

The present invention solves the above-mentioned disadvantages, and aims to provide a microwave tube that has a simple structure and allows the Q value of the cavity to be set relatively arbitrarily.

[Structure of the Invention (Means for Solving the Problems) This invention provides an inner cavity wall provided inside the hermetically sealed outer peripheral wall of a resonant cavity, and at least one Q
This is a microwave tube with a through hole for adjustment.

(Function) According to the present invention, it is possible to obtain a microwave tube that has a simple structure, allows the Q value to be arbitrarily set, and is robust.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

When this invention is applied to the fundamental wave cavity of a multi-cavity klystron, the main part is constructed as shown in FIG. 1, in which a plurality of resonant cavities 1 are connected by a drift tube 2. An inner cavity wall 4 is provided inside the hermetically sealed outer peripheral wall 3 of the resonant cavity 1 . The cavity inside this inner cavity wall 4 forms an electrical cavity. Furthermore, this inner cavity wall 4 is provided with at least one Q adjustment hole 5 for adjusting Q to an appropriate value. Note that this through hole 5 makes the resonance cavity 1 and the outer space S a vacuum region.

In this case, once the number of through holes 5 and the value of Q are determined experimentally, the number of through holes 5 corresponding to the determined value of Q can be determined accurately. Furthermore, since there is no need for conventional ceramics, the number of parts is small and manufacturing is easy.

In the figure, 3a% and 3b are both end plates of the cavity, 6 is the drift pipe gap, 7 is a welding ring, 8.9 is a reinforcing flange, 10 is a screw for adjusting the resonance frequency, 11 is a water channel, and 12 is a resonance This is a thin section for frequency fine tuning.

(Other Embodiments) FIG. 2 shows another embodiment of the present invention, which provides the same effects as the above embodiments. That is, in this other embodiment,
This is an example in which this invention is applied to a second harmonic cavity, and the inner cavity wall 4 provided inside the hermetically sealed outer peripheral wall 3 of the resonant cavity 1 is closer to the drift tube 2 than in the above embodiment. Located in
The cavity inside this inner cavity wall 4 forms a second harmonic cavity.

The outer cavity of the inner cavity wall 4 has the same outer diameter as the fundamental wave cavity.

In the case of a klystron, if a second harmonic cavity is used, the outer diameter of only this part becomes small, so it tends to become mechanically weak. Therefore, conventionally, in order to increase the mechanical strength, a support rod or the like is used in this part to support the flanges 8.9 attached above and below. At this time, it is necessary to manufacture the lengths of the plurality of rods with high precision. If this were not the case, a non-uniform force would be applied to the cavity when soldered, potentially causing the klystron to bend. However, if the shape of this other embodiment is adopted, the conventional disadvantages can be solved.

Since a cylinder having the same outer diameter as the fundamental wave cavity is placed outside the second harmonic cavity, it is also possible to use common parts.

The embodiment shown in FIG.
5 is formed in an appropriate number. Depending on the size and number of the recesses 15, the Q value of the cavity can be set arbitrarily. In this embodiment, the inner cavity wall 4 is connected to both end plates 3a.
s 3b in a vacuum-tight manner, and the outer peripheral wall may be simply mechanically and firmly fixed.

Furthermore, at least one through hole and at least one recess may be formed in the inner cavity wall 4 at any desired location. In particular, if a through hole is formed and both the inner cavity and the outer air conditioner are evacuated, no external pressure is applied to the inner cavity wall 4, and therefore it can be constructed from a relatively thin metal cylinder.

[Effects of the Invention] According to this invention, an inner cavity wall is provided inside the hermetically sealed outer peripheral wall of the resonant cavity, and a plurality of Q adjustment through holes are bored in this inner cavity wall. Therefore, the structure can be simplified and the Q value can be set relatively arbitrarily.

[Brief explanation of the drawing]

FIG. 1 is a half-longitudinal cross-sectional view showing essential parts of a multi-cavity klystron according to one embodiment of the present invention, and FIGS. 2 and 3 are main parts of multi-cavity klystrons according to other embodiments of the present invention. FIG. DESCRIPTION OF SYMBOLS 1... Resonance cavity, 2... Drift tube, 3... Hermetically sealed outer peripheral wall, 4... Inner cavity wall, 5... Through hole for Q value adjustment, 15... Q Recess for value adjustment. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] In a microwave tube in which a plurality of resonant cavities are connected by a drift tube, an inner cavity wall is provided inside the hermetically sealed outer peripheral wall of the resonant cavity, and the inner cavity wall A microwave tube characterized in that at least one through hole or recess for Q adjustment is bored in the tube.