JP2808938B2 - High power microwave tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high power microwave tube using an electromagnet as a focusing device.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional high-power microwave tube using an electromagnet as a focusing device captures an electron beam from an electron gun and captures the electron beam from the electron gun. It basically comprises a collector, a high-frequency circuit disposed between the electron gun and the collector, and a focusing circuit for focusing the electron beam.

Next, the operation of each section will be described. The electron gun section
A cathode 5 for emitting an electron beam, a cathode support 2 for supporting the cathode 5, a Wehnelt electrode 3 and an anode electrode 6 for forming an electric field for converging and accelerating the electron beam, and electrically insulating between the electrodes. It is composed of an insulating stone 4 and an electron gun support 1 that supports an electron gun section. The collector section includes a collector 14 for capturing an electron beam emitted from the electron gun section.

The high-frequency circuit section includes a high-frequency circuit section 11 that modulates the speed of an electron beam emitted from an electron gun by a high-frequency signal, collects the electron beams, and converts the energy of the electron beam into a high-frequency signal. The focusing circuit unit forms a magnetic field necessary for passing the electron beam emitted from the electron gun unit through the high-frequency circuit unit while keeping the electron beam focused. The focusing circuit unit includes an electromagnet coil 10 and an electron gun-side pole piece that is a magnetic material. 7, a lower yoke 8, an upper yoke 12, a collector-side pole piece 13, and a spacer 9 used for positioning the electromagnet coil 10.

The conventional magnetic flux density distribution on the central axis of the electron gun between high power microwaves is shown by a solid line in FIG.
Since the magnetic flux density distribution affects the diameter and the ripple rate of the electron beam passing through the high-frequency circuit, the shape of the focusing circuit is experimentally changed to obtain the optimum magnetic flux density distribution. At this time, the required perforance and withstand voltage stability are required at the same time, which is a design constraint.

[0006]

In this conventional high-power microwave tube, the presence of the electromagnet spacers 9 increases the leakage flux in the radial direction, and the flux density in the portion A in FIG. 3 becomes relatively small. . However, if it is desired to further increase the magnetic flux density at the portion A in FIG. 3 in order to obtain the required electron beam diameter, ripple rate, perforance, and withstand voltage stability, it may not be possible to realize this. If the spacer 9 is removed, the magnetic flux leaking in the radial direction is reduced and the magnetic flux density of the portion A in FIG. 3 is increased. However, since it is necessary for the positioning of the electromagnet coil 10 and the piping of the water cooling pipe for cooling the electromagnet coil, it is removed. Can not do.

[0007]

SUMMARY OF THE INVENTION The present invention provides an electron beam.
Captures the electron gun and the electron beam from the electron gun
To be placed between the electron gun section and the collector section
The high-frequency circuit part and the outer periphery of the high-frequency circuit part
In high power microwave tube and a focusing circuit portion made of electromagnets, magnetic pole pieces of the electron gun side of the focusing circuit is recessed into the collector section along the tube axis concave
It is characterized by having a like-shaped structure .

[0008]

According to the present invention, the magnetic flux density in the portion A can be increased by moving the portion A to a position before the leakage magnetic flux spreads in the radial direction.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a high power microwave tube according to one embodiment of the present invention. The electron beam emitted from the cathode 5 is focused by an electric field between the Wehnelt electrode 3 and the anode electrode 6. The electron beam that has passed through the anode electrode 6 remains focused by the magnetic field of the magnetic circuit system including the electromagnet coil 10, the collector-side pole piece 13, the upper yoke 12, the lower yoke 8, the spacer 9, and the electron gun-side pole piece 7. 11 and is captured by the collector.

In this embodiment, the electron gun side pole piece 7 protrudes in the direction of the electromagnet coil, and the magnetic flux density distribution of the electron gun portion is as shown by the broken line in FIG. Could be larger. In addition, this enables an electron gun structure that could not be realized conventionally. In the present embodiment, the distance between the anode electrode 6 and the electron gun-side pole piece 7 can be made wider than in the past, and the structure has more margin in terms of withstand voltage. did it.

[0011]

As described above, according to the present invention, the magnetic pole density distribution of the electron gun portion is changed from the solid line in FIG. 2 to the broken line in FIG. As a result, the magnetic flux density at the portion A could be made larger than before. Further, the more the electron gun pole piece protrudes in the direction inside the electromagnet coil, the higher the magnetic flux density in the portion A can be. Therefore, if the present invention is used, the degree of freedom in designing the electron gun can be increased.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of the present invention.

FIG. 2 is a diagram showing a magnetic flux density distribution of an electron gun unit according to the present invention and a conventional example.

FIG. 3 is a cross-sectional view of an example of the related art.

[Explanation of symbols]

 Reference Signs List 1 electron gun support 2 cathode support 3 Wehnelt electrode 4 insulating stone 5 cathode 6 anode electrode 7 electron gun side pole piece 8 lower yoke 9 spacer 10 electromagnet coil 11 high frequency circuit section 12 upper yoke 13 collector side pole piece 14 collector

Claims (1)

(57) [Claims] An electron gun for emitting an electron beam;
A collector for capturing the electron beam from the gun, and an electron gun
High-frequency circuit section between the
Focusing circuit consisting of electromagnets arranged on the outer periphery of the frequency circuit
In high power microwave tube having a section, the converging times
Magnetic pole pieces of the electron gun side of the road section, along the tube axis
A high-power microwave tube having a concave structure recessed toward the collector .