JPS5943634Y2 - traveling wave tube device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a traveling wave tube device using a periodic alternating magnetic field type electron beam focusing device.

As is well known, in a traveling wave tube device, an electron beam emitted by an electron gun passes through the inside of a helix made of a spiral conductor and is collected at a collector.

The electron beam focusing device, which focuses the electron flow to a constant diameter so that the diameter of the electron beam does not expand when it passes inside a long and narrow helix, uses an annular disk as shown in Figure 1. A large number of shaped permanent magnets 11 and pole pieces 12 are arranged alternately.

This electron beam focusing device is assembled in advance by caulking, and the helix portion of the traveling wave tube main body (not shown) is inserted into this central space, and the helix portion of the traveling wave tube body (not shown) is inserted into the center space, and the helix portion is placed on the central axis of the electron beam, that is, on the central axis of the focusing device. An axial magnetic field that changes periodically in a sinusoidal manner is created, which acts in the same way as if magnetic lenses were placed at equal intervals, and serves as a focusing lens to prevent the electron beam from divergent due to mutual repulsion.

Note that an input waveguide 13 and an output waveguide 14 are provided near both ends of the electron beam focusing device, respectively.

When the waveguides 13, 14 are arranged in the focusing device, the permanent magnet 1
1 is partially missing at the waveguide position, which disrupts the magnetic field distribution described above.In order to prevent this, for example,
Improvements such as those disclosed in Publication No. 6-13273 could be made.

A collar 15 is formed at both ends between the waveguides 13 and 14, and has a cylindrical portion with an inner diameter that can accommodate the electron beam focusing device and a length that is slightly shorter than the distance between the grooved waveguides 13 and 14. An outer cylinder 16 having a diameter is interposed therebetween, and the groove wave tubes 13 and 14 are fastened to each other by the collar 15, thereby firmly holding the electron beam focusing device.

In addition, in order to protect the parts of the traveling wave tube body protruding from both ends of the focusing device from damage caused by external force, another outer cylinder 18 having a flange 17 is connected to the input/output waveguide 13, 14 at the flange 17.
They are each tightened and fixed.

In general, periodic alternating magnetic fields are always finite, and the same -
Even if a strong magnet is used, disturbance of the magnetic field occurs at the terminal part as a terminal effect, and a uniform periodic magnetic field cannot be obtained.

For this reason, it is necessary to correct the terminal effect by using magnets of different strengths near the terminals or by changing the dimensions of the magnets to achieve a satisfactory periodic magnetic field. In the apparatus, the electron beam focusing device includes an outer tube 16.
Once held, it is shielded by the outer cylinder 16 and also by the other outer cylinders 18 at both ends, so a magnetic material is used to correct the terminal effect as described above. Magnet 1 using a piece of iron or a piece of pebble
There is a drawback that adjustment of step 1 cannot be performed externally.

The present invention has been made to eliminate the above-mentioned drawbacks, and provides a traveling wave tube device that can easily adjust the magnets of a periodic alternating magnetic field device and can correct the end effects of the periodic magnetic field.

An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 2a and b, a periodic alternating magnetic field focusing device 20
is a permanent magnet 21. It consists of a pole piece 22, and an input waveguide 23 and an output waveguide 24 are arranged near both ends.

Further, two plate-shaped metal members 25 are provided at both ends of the periodic alternating magnetic field focusing device 20, holes 26 are bored at four locations around the metal member 25, and four long bolts 27 are inserted between the two metal members at both ends. It passes through the member 25 and has a nut 28 screwed into it at one end.

By firmly tightening the nut 28, the input/output waveguide 23
．． The periodic alternating magnetic field focusing device 20 including 24 can be firmly fixed without loosening.

Further, the periodic alternating magnetic field focusing device 20 firmly fixed in this way is placed on a thick metal substrate 29, and the input/output waveguide 23 is placed on the thick metal substrate 29.
．． 24 or the metal members 25 at both ends and the substrate 29 are fixed using screws or the like.

The cover 30 is intended to protect the entire traveling wave tube device from external forces, etc., but the traveling wave tube main body (not shown) is inserted into the periodic alternating magnetic field focusing device 20 before attaching the cover 30. The terminal effect of the periodic magnetic field is corrected so that the electron beam transmittance is maximized.

This correction is performed by attaching a small iron piece or a small magnet piece to the magnet 21, etc., but in the device of the present invention, unlike in conventional devices, there is no shielding object and the magnet 21 is exposed, so it is extremely easy. can be done.

The above correction operation is performed while observing the electron beam transmittance within the helix portion of the traveling wave tube with an ammeter or the like.

In the above embodiment, the metal member 28 is described as having a rectangular plate shape, but the metal member 28 is not limited to this, and may be freely deformed to an annular shape, a cylindrical shape, or the like.

Further, it goes without saying that the cover 30 is not limited to a rectangular shape, but may also be circular.

Furthermore, there is also a modification in which the entire periodic alternating magnetic field device, which is firmly fixed by the metal member 25 and the metal rod 21, is inserted and fixed into a metal cylinder.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a focusing magnetic field device section of a conventional traveling wave tube device with the traveling wave tube main body removed, FIG. A perpendicular to the axis of diagram a
It is a sectional view looking at the left side in -A/ plane. In the figure, 20... is a periodic alternating magnetic field focusing device, 21... is a permanent magnet, 22... is a pole,
Piece, 23... Input waveguide, 24...
...Output waveguide, 25...Metal member, 26...
...Hole, 27..., ...Bolt, 28...
- Nut, 29... board, 30... cover.

Claims (1)

[Scope of utility model registration request] A traveling wave tube body, a plurality of permanent magnets and a plurality of pole pieces are arranged alternately so as to surround the outer periphery of the helix portion of the traveling wave tube body, and an input/output waveguide is further arranged between the permanent magnets. In the traveling wave tube device in which the permanent magnet and the pole piece are inserted, a periodic alternating magnetic field focusing device including an input/output waveguide is provided with metal members at both ends, and a plurality of metal A traveling wave tube device characterized in that the periodic alternating magnetic field focusing device is firmly fixed by screwing with a rod, and the entire fixed periodic alternating magnetic field focusing device is fixed to a metal substrate.