JPS62278732A - Gyrotron - Google Patents

Abstract

PURPOSE:To obtain good high-frequency output power low in a mode mixture rate of out-put, by setting up a sweep coil on the circumference of a collector part, between a main coil an output aperture side cancel coil within the repercussion range of a magnetic field of the main coil. CONSTITUTION:On the circumference of a gyrotron body 5, there are provided with an electron gun coil 6, a main coil 7 and an output aperture side cancel coil 8 each being correspondent to an electron gum 1, a resonant cavity part 2 and a collector part 9. And, a sweep coil 10 is set up between the main coil 7 and the output aperture side cancel coil 8 within the repercussion range of a magnetic field of the main coil 7. With this constitution, there is unnecessary to install a taper part in the collector part 9, therefore such parts that mode conversion may occur are decreased. In consequence, good high-frequency output power low in a mode mixture rate of output is securable.

Description

[Detailed description of the invention] 3. Detailed description of the invention [Purpose of the invention] (Industrial application field) This invention applies to gyrotrons.

(Prior Art) Conventionally, a high-power electron beam gyrotron is configured as shown in FIG. 3, and has an electron gun section 1, a resonant cavity section 2, a collector section 3, and an output window 4 for transmitting electromagnetic waves. On the outer periphery of the gyrotron body 5, an electron gun coil 6 and a main coil 7 are arranged.
and an output window side canceling coil 8 are arranged. As is clear from the figure, the collector W53 has a dog-shaped inner diameter and is tapered downward between the collector W53 and the output window 4. This reduces the heat flux per unit area to the inner surface of the collector section 3, thereby making it smaller than the limit value determined by the material of the wall surface of the collector section 3.

(Problem to be Solved by the Invention) However, in the conventional gyrotron as described above, since the collector section 3 also serves as an output waveguide, the mode is converted in the tenor sections 3 and 3b provided before and after the collector section 3. There was a problem with output mode mixing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gyrotron that can provide high-quality output with a low proportion of output mode mixing.

[Structure of the Invention (Means for Solving Problems)] This invention reduces the taper part where output mode mixing occurs, makes the inner diameter of the collector part the same as the output waveguide, and reduces the influence of the magnetic field of the main coil. This is a gyrotron in which a sweep coil excited by alternating current is disposed between the main coil and the output window side cancellation coil within the area.

(Function) In order to reduce the heat influx of the electron beam into the wall surface of the collector unit per unit area, the sweep coil disposed outside the collector unit is excited with alternating current, and the magnetic field of the collector unit is changed over time. By varying the temperature, the electron beam that hits the wall surface of the collector section is dispersed over a wider area of the collector section, so that the time average of the large flux density of the heat flux on the wall surface of the collector section is below a certain limit value determined by the material of the collector section. I have to.

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

The gyrotron according to this invention is shown in FIGS.
), (a) is a characteristic curve diagram showing the relationship between each electron beam trajectory and the axial magnetic flux density in the collector portion, and (b) is a cross-sectional view showing the configuration.

The same parts as in the conventional example (Fig. 3) are given the same reference numerals.The gyrotron main body 5 has an electron gun part 1, a resonant cavity part 2, a collector part 9, and an output window 4 connected in sequence in a straight line. It is configured. In this case, the collector section 9 consists of a conduit pipe with the same inner diameter, and there is no 4 section like the conventional one.

Further, on the outer periphery of the gyrotron body 5, an electron gun coil 6, a main coil 7, and an output window side cancellation coil 8 are arranged corresponding to the sleeper gun section 1, the resonance cavity section 2, and the collector section 9, respectively. There is. A sweep coil 10 is disposed between the main coil 7 and the output window side canceling coil 8 within the spread region of the magnetic field of the main coil 2.

This sweep coil 10 is excited by an alternating current during operation, and the waveform of this alternating current is as shown in FIG. A in this figure 2.

The respective electron beam trajectories and axial magnetic flux densities at the collector section 9 in each phase of B and C are shown in FIG.
It corresponds to In addition, the frequency of alternating current is l0I(
The appropriate range is from z to 100)Iz.

In FIG. 1(b), 11 indicates an electron beam, and 12 indicates an output flange.

[Effects of the Invention] According to the present invention, the collector portion is a waveguide with the same inner diameter, and there is a sweep between the main coil and the output window side canceling coil within the @ field spread region of the main coil. Since the coil is provided, there is no need to provide a portion of the collector section, and therefore the number of sections where mode conversion occurs is reduced. As a result, a high-quality high-frequency blade with a low proportion of output mode mixing can be obtained.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) show a gyrotron according to an embodiment of the present invention, and FIG. 1(a) is a characteristic curve diagram showing the t ratio between each electron beam trajectory and the axial magnetic flux density in the collector portion,
(b) is a sectional view showing the structure, FIG. 2 is a waveform diagram showing all the waveforms of the alternating current that excites the sweep coil used in the present invention, and FIG. 3 is a sectional view showing the conventional gyrotron. DESCRIPTION OF SYMBOLS 1... Electron gun part, 2... Resonance cavity part, 4... Output window, 5... Gyrotron main body, 6... Electron gun coil, 7... Main coil, 8... - Output window side cancellation coil, 9... Collector section, 10... Sweep coil.

Claims (2)

[Claims] (1) A gyrotron in which an electron gun coil, a main coil, and a cancellation coil on the output window side are arranged around the outer periphery of a gyrotron body that has an electron gun section, a resonant cavity section, a collector section that also serves as a waveguide, and an output window. A sweep coil excited by alternating current is disposed on the outer periphery of the collector section between the main coil and the output window side canceling coil within the spread region of the magnetic field of the main coil. Gyrotron. (2) The gyrotron according to claim 1, wherein the collector portion is a waveguide having the same inner diameter.