SU302766A1 - PATENT TECHNICAL LIBRARY - Google Patents

Description

The invention relates to electronic devices, and can be used in various electron beam devices, where a large number of electron beams need to be formed and controlled by density in a wide frequency band.

Two designs of multipath cathode-modulator nodes are known: a cathode-modulator node with a cathode common to all beams, with the electron flow divided into separate beams and with modulators separate for each beam; a cathode-modulator circuit with separate cathodes for each beam, which is a simple combination of several single-beam electron guns. In both designs, all the electrodes forming and controlling the electron beams are located under a common vacuum shell.

For well-known designs of multipath cathode-modulator nodes are typical:

the cumbersome design of a vacuum device with a multipath cathode-modulator unit and a limited number of beams formed;

the presence of parasitic connections and a bridge between the control electrodes of adjacent beams, requiring the introduction of special screens that complicate the design;

reduced reliability of the vacuum shell of the device due to the large number of leads in the (electrical vacuum jacket);

limited working frequency band; working frequency band is determined by the design

cathode modulator node and is for

most common designs with

modular oxide end cathode

in the form of a disk having holes approximately

from O to 200 MHz.

In addition, in the cathode-modulator units of the finished device, it is not possible to change the number and mutual arrangement of the rays.

Purpose: the invention is the creation of a multipath cathode-modulator unit with increased

LOT, the location of the electron beam,

independently controlled by the current density in

Chirac frequency range.

This is achieved by the use of controlled low-inertia radiation sources, which play the role of modulators of electron beams, and are located outside the vacuum, the radiation of which is transferred by means of an optical system to the photocathode, which provides emission current to all electrons.

In the drawing. Is a schematic representation of the proposed cathode-modulator node. For example, semiconductor quantum generators (PCG) on gallium arsenide, for example, the light emission of which can be modulated in the frequency band up to 10 KHz. These radiation sources are small and have significant lily patches on modulation characteristics. The sources of radiation are located outside the vacuum, and are mechanically fixed in the form of a specific system. If necessary, the relative position in the number of radiation sources can be changed, so that the relative position and the number of electron beams in the cathode modulator node change accordingly. Optical system 2 connects the radiation sources to the photocathode 3 located in the vacuum shell of the compactor 4. As an optical system, a lens system, optical fibers, etc. can be used. In the design described, the optical system works like a laser with decreasing image scale , therefore, the electron beams generated by the. fayukodode. can be located., gaty gothic with any desired density, regardless of the density of the location of their own radiation sources. The need to use the optical system is no longer necessary if the radiation sources have a sufficiently sharp radiation pattern of the emitted light flux. A photocathode, common to all rays, must be soldered with radiation sources, i.e. the spectral sensitivity of the photocathode should correspond to the spectrum emitted by the source and the radiation. Using a photocathode as an emitter has certain characteristics before using an oxide cathode as a source of electrons in conventional cathode modulator nodes: the photocathode is not ready for operation (channelless cathode) and the photocathode has extremely low inertia of electron emission (10 sec); the photocurrent is associated with a linear dependence with the amount of luminous flux incident on the photo-cathode, up to certain values of the luminous flux. The presence of linear sections on the characteristics linking the input electrical signal with the amount of light flux emitted by the PCG and the value of the light flux incident on the photocathode. change electrical signals in a certain range. This linearity of the modulation characteristic of a writeable cathode modulator node may be useful in some cases (especially considering that cathode modulator nodes of known types with oxide cathodes cannot work with linear conversion of the input signal into the beam current ,. have a lily modulation characteristics). The operation of the cathode-modulator unit is as follows. Electrical input signals are sent to controlled low inertia sources of radiation 1, the light radiation of which is modulated by the indicated signals. Optical system 2 transfers modulated radiation to a photocathode 3 located under the vacuum shell of Instrument 4. Under the action of radiation from certain points of the photocathode, photoelectrons will be emitted (electron beams), by which the current of each beam will be modulated. . Further, the electron beams can be focused by an electric current or magnetic rays, deployed by means of a deflection system on a memory screen or a luminescent screen. Electron rays, if necessary, can be enhanced by. use thin films with emission on the chamber with the help of a multi-chamber image intensifier with amplifying cascades of the photocathode-phosphor on a common transparent substrate. The subject of the invention and the Cathode modulator unit for the formation and control of a large number of electron beams, containing a cathode common to all studies and separate modulators, characterized in that, in order to increase the density of the beams and expand the working frequency band, The cathode has a photocathode, and the modulators are designed as a system of controlled radiation sources located outside the vacuum and optically coupled to the photocathode.