RU2558677C2 - Device to measure intensity of electric field of magnetic type wave in wave guide - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention relates to measurement devices for determination of intensity of electric field of a magnetic type wave in a wave guide. The device represents a combination of miniature β-spectrometer and an electron gun, which are mounted on a tubular vacuumized wave guide. Measurements with the help of the proposed device are carried out in the following manner. The flux of electrons injected by the electron gun passes via the wave guide, through which waves of magnetic type spread, and the intensity of electric field of which changes according to the law: $$\overrightarrow{E}={\overrightarrow{E}}_o\sin (\omega t+{\phi }_o).$$

At the same time a part of the flux of electrons gets into a phase of maximum value of electric field intensity. Then electrons get into a β-spectrometer, with the help of which using the available method they fix the maximum value of electric field intensity in the surveyed wave guide.

EFFECT: technical result of this invention is development of an instrument for direct and accurate measurement of electric field intensity in waves of medium and high capacity and magnetic type in a tubular wave guide.

2 dwg

Description

The present invention relates to a technique for measuring the electric field strength of electromagnetic waves in tubular waveguides.

The aim of the invention is to provide a device for direct and accurate measurement of the electric field strength of a magnetic type wave in a tubular waveguide of medium and high power levels.

An analogue of the invention is an electric probe, which is a piece of coaxial cable, the central core of which through a hole in the waveguide is inserted into the field of an electromagnetic wave in the waveguide.

The analogue operates as follows. The electric field of the wave traveling in the waveguide induces an EMF in the central core of the coaxial cable, the end of which is inserted into the waveguide. This allows using the appropriate set of devices to obtain information about the wave mode in the waveguide (see Valitov R.A., Sretensky V.N. "Radio measurements at superhigh frequencies", Military Publishing House of the Ministry of Defense of the USSR, M., 1958, p. 35, Fig. 2.4 , p. 219, p. 5.19).

The disadvantage of the analogue is that in the case of monitoring a vacuum waveguide with a high level of wave power in it, it is very difficult to ensure the conditions of the vacuum technology and the stability of the electric probe in the waveguide. The probe will burn and spark!

The second analogue is an electron-beam device in which an electron beam is transmitted through a waveguide along the electric component of a magnetic wave. The effect of the interaction of the electron beam with the electric field of the wave under study is recorded by the braking voltage at the electrode in front of the collector, which registers the current of transmitted electrons (see Harvey A. "Microwave Technique", v.1, Sovetskoe radio. M., 1965, p.202 )

The disadvantage of the second analogue is that it will be dangerous for the operator when studying waveguides with an average and high power level, because it will be necessary to supply voltages of several kilovolts or more to the braking electrode.

The prototype of the invention is a β-spectrometer, which was used to measure the energy of accelerated electrons with energies of the order of 0.3-0.5 MeV (see Ishkov A.P. Candidate dissertation. Tomsk, NIIYaF TPI, 1969, p. 42, fig. 16, photo 5, 6. “An experimental study of autoresonant electron acceleration”).

в волноводе, при соответствующей фазе ускоряется или тормозится. Это изменение энергии исходного пучка электронов можно зафиксировать регистрацией изменения тока в отклоняющих обмотках β-спектрометра при снятии β-спектра электронов, прошедших на коллектор.The action of the prototype is that the electron beam, as in the second analogue, flying through the waveguide, is exposed to the action of the electric field vector $$\overrightarrow{E}$$

in the waveguide, with the corresponding phase is accelerated or decelerated. This change in the energy of the initial electron beam can be fixed by recording the change in current in the deflecting windings of the β-spectrometer when taking the β-spectrum of electrons transmitted to the collector.

As an example, the invention is presented in the drawings.

In FIG. 1 shows the main view of the device in plan with the removed upper half of the magnetic circuit.

In FIG. 2 shows a cross section of a rotary magnet.

The positions in the figures show:

1 - waveguide with the investigated wave,

2 - electron gun,

3 - vector of the electric field in the waveguide,

4 - bellows

5 - h-shaped vacuum chamber of a β-spectrometer,

6 - deflecting winding,

7 - external magnetic circuit,

8 - direct-span collector,

9 - collector registration β-spectrum,

10 - equilibrium electron trajectory.

The invention operates as follows.

The electron beam from the electron gun 2 under the influence of its initial speed through the passage hole in the waveguide 1 penetrates into the waveguide and under the action of the electric field vector in the waveguide

$$\overrightarrow{E}={\overrightarrow{E}}_o\sin (\omega t+{\varphi }_o)$$

depending on the injection phase, it accelerates or slows down, respectively, increases or decreases its energy. By selecting the electric current in the deflecting winding 6, any electrons injected into the waveguide 1 by the electron gun 2 can be derived along the equilibrium path 10 to the collector for recording the β-spectrum 9, and their β-spectrum can be registered accordingly. Formally, the β-spectrum is the dependence of the collector current 9 on the current of the deflecting winding 6. By the known analytical dependences, the mode of the electromagnetic wave in the waveguide under study can be controlled.

The bellows 4 is used for technological adjustment of the device so that the electron beam from the gun 2 effectively flies to the direct-span collector 8.

The h-shaped chamber provides vacuum conditions for the movement of the electron beam from the electron gun 2 to the β-spectrum recording collector 9. It is made of aluminum in the prototype.

The external magnetic circuit 7 is made of mild steel. A deflecting winding consists of two sections and is formed by a winding wire (see Zigban K. Beta and Gamma Spectrometry. Fizmatgiz, M., 1864).

The control of the β spectrometer can be computerized.

The main advantage of the invention is the reliability of the measurements of the electromagnetic wave mode in the waveguide. The dimensions of the device are small, the vacuum chamber is half a bag, and the deflecting magnet is kalach. In general, this will be a very compact device and can be successfully applied to any waveguide with a transverse wave of medium and high power levels.

Claims (1)

A device for measuring the electric field strength of a magnetic type wave in a waveguide, consisting of an electron gun and a β spectrometer, characterized in that the evacuated waveguide under investigation is mounted between the electron gun and the β spectrometer so that the electron beam passes through the evacuated waveguide under study along the paths that coincide with electric field lines in a waveguide.

Images