SU1114237A2 - Memory cathode-ray tube - Google Patents

Abstract

MEMORIZE ELECTRON BEAM ON auth.St. No. 695417, characterized in that, in order to improve the reliability of the information during physical measurements, it additionally contains a dielectric layer located on. One section of the channels of a microchannel plate is on the side facing the signal electrode, and the thickness of the amp. The dielectric layer satisfies the condition — about 3 the channel diameter of the microchannel plate.

Description

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The invention relates to electronic engineering, namely, to high-speed storage electron-beam tubes (ZELT) intended for time-to-scale conversion (FEP) of single-time electrical signals containing an amplification channel channel (MCP). According to the main author. ev; By 695417 a known electron storage tube l is known, the ZELT contains electronic write-read and write projectors, an amplifier MCP and a signal electrode. Electronic searchlights for recording and reading are located on one side of the MCP, on the other side of the IPC, along the course of the electron flows, there is a signal electrode. Amplifier SHP at the same time is a storage element. Recording of the recorded signal is carried out on microchannel plates in the mode in which the current value of the recording beam corresponds to the Nasiacene mode of the IPC channels. When the signal is recorded under the beam in the MCP, a charge relief is created in the form of surface positive charges on the walls of the MCP channels, corresponding to the image of the input signal. Then the MCP is irradiated with an electronic readout beam, expanded into growth, on the same side as the recording, at a current value corresponding to the saturation mode of the MCP channels. When reading, the electron beam of the reading spotlight scans the input surface of the MCP with a reading speed much lower than the writing speed. The output current of the MCP, detected by the signal electrode, is thus modulated by the charging relief formed on the walls of the MCP channels during recording. The output read signals are obtained due to the difference in the output current from the MCP sites on which preliminary recording was made, and the areas where there was no recording. The total reading time (the frame sweep time for the solution reads Pania) is determined from the CHIF ratio of 0.1. from the essay - - C. CHIT, the total time of reading by the beam, uncovered in the growth, counted from the moment of recording, restored, the MCP from the altered state to the end of 7. 2, time. The advantage of the known ZELT is the high resolution. A disadvantage of the known ZELT is the low reliability of the information due to the low coefficient of large-scale information conversion. The coefficient of the profit center of the information Krr is defined as the ratio of the read time T fi, j, to long-p. I / t sweep record pr-ad Mala magnitude K is due to the low efficiency of the MCP as a storage (storage) element. This is explained next. When recording, the largest surface positive charge that forms the charge relief corresponding to the image of the signal under study is formed near the output portions of the MCP channels, since as the electron beam of the recording approaches the output portions of the MCP channels, more and more secondary electrons leave the channel walls. This is due to the distribution of the Ku gain factor along the channel .., kg j K ,,,,: fc; -k where k is the gain per unit channel length, -i - 1, 2. . . . Due to the fact that the input and output planes of the MCP are metallized, since they are an integral part of the electrical contact for supplying the required supply voltage to the MCP, the inner output sections of the MCP channels adjacent to them are due to the metallized conductive coating technology. on the ITUC. Those. near the output sections of the MCP channels, there are regions with increased conductivity for electrical charges. In addition, there are leakage currents on the surface of the MCP channels due to the finite conductivity of the surface layer of the channel. All this leads to a decrease in the storage time of the charge relief on the walls of the MCP channels, especially in their exit areas, and also reduces the effective value of the charge relief, i.e. MCP as a storage element has low efficiency. The storage time of the charge relief in the MCP, i.e. the recovery time of the MCP from the saturation state to the initial state is several milliseconds. The short recovery time limits the read time, since C 0 0 1 9ssg-Pr the scan sweep time 10 NS and the read time the scaling factor is equal to. Moreover, the low efficiency of the MCP as a storage element limits the maximum write speed in the ZELT. The aim of the invention is to increase the reliability of information when conducting physical measurements by increasing the scale-time conversion factor. This goal is achieved by the fact that the storage electron beam tube is auth. No. 695417 additionally contains a dielectric layer located on the output sections of the channel of the microchannel plate on the side facing the signal electrode, the thickness D of the dielectric layer satisfying the condition of 10 tons, where j is the diameter of the MCP channel. FIG. 1 shows the proposed ZELT, general view; in fig. 2 is an enlarged view of the storage element J in FIG. 3 is a graph showing the change in the value of the output read signal from the read time. The ZELT according to the present invention comprises a glass envelope 1; Record electronic searchlight 2, Sshitsan 3 electronic searchlight, microchannel plate 4 with channels 5, dielectric layer 6, signal electrode 7, luminescent screen 8. Record electronic searchlights 2 and Skoit 3, located on one side of the MCP 4, on the other side of which along the electronic The streams are located in the signal electrode 7, for which the adjuvant coating of the luminescent screen 8 of the tube was used. The dielectric layer 6 is applied to the output portions of the MCP 4 channels on the side facing the signal electrode 7. MCP 4 with a layer of dielectric 6 applied to its output surface is simultaneously an amplifying and storage element. High dielectric dielectrics with high specific resistance (, cm) dielectric constant and high secondary electron emission coefficient, for example, magnesium oxide, potassium chloride, etc., are used as dielectrics. The dielectric layer 6 does not overlap the channels 5 of the MCP 4, but is in direct contact with the inner surface of the output sections of the channels 5 of the MCP 4, which, like the plane of the MCP, is metallized. In contrast to the known ZELT according to this invention, the storage element is a two-layer system consisting of MCP 4 and located on the output sections of channels 5 of MCP 4 of a dielectric layer 6. ZELT works as follows. A constant positive voltage is set on the memory element (kV. To simplify the operation of the ZELT at the input of the memory element (MCP plane 4 facing the electronic searchlights) a zero potential is established. A constant positive potential is applied to the signal electrode (. (About 2-3 kV) to create the required electric field between the output of the storage element and the signal electrode 7, after which the signal under test is recorded. During recording, the beam 13ap of the recording projector 2 irradiates in the same plane of the MCP 4 according to the law of the signal under investigation. In this case, the recording electron beam, the passage through the MCP 4, is amplified. The amplified electron flux by the electric field (lli (J ") O is diverted to the signal electrode 7. When recording the signal under study on the channels of the MCP 4 and an additional layer of dielectric 6 due to the removal of surface electrons from these surfaces of the secondary electrons, due to the fact that the gain of Kus MCP 4 increases with increasing channel length (1Cy (. PC, where 1 1, 2 .. C, (C is the gain per unit length of the MCP channel), the maximum number of secondary electrons leaves the surface of the code sections of channels 5 of the MCP 4, which are in direct contact with the dielectric layer 6 (see Fig . 2 a). As a result, the maximum number of surface positive charges is formed here. Thus, when recording on the output sections of the memory element, a charge relief is created corresponding to the image of the signal under study. The presence of the dielectric layer 6 on the output sections of the channels 5 of the MCP 4 leads to the fact that, near the output sections of the channels 5 of the MCP 4, a layer is depleted of electric carriers and has an increased resistance to conduction current, which prevents equalization (erasure) of the charge relay. ;F. As a result, the time during which the relief is preserved, and hence the readout time, is increased. When tolling D (Fig. 2b) dielectric layer 6 satisfying condition 10 where A is the diameter of channel 5 of the MCP 4, the storage time of the recorded information in comparison with the known ZELT is increased by 2 orders of magnitude. The upper limit -4- U 10 is selected from the condition of maintaining the necessary transparency of channels 5 of the MCP 4 for the electron flow. With a greater thickness of the dielectric layer 6, the channel 5 is blocked by a dielectric. The GTR and the specified ratio of the loss of transparency of the channels 5 due to the dielectric layer 6 does not exceed 1%, which has practically no effect on the operation of the LELT. The lower limit of the thickness of the layer 10 is selected from the time needed to ensure the necessary secondary electron emission from the walls of the channels 5. The reading is performed on the same side of the MCP 4 as the recording, at a speed much lower than the recording speed. The reading electron beam, expanded to the height, scans the input plane of the MCP 4. When the reading beam passes through those parts of the MCP 4, where there was no recording, it is amplified. At the same time at the output of the storage element current 1 is maximum. This current is diverted by an electric field (O 2 - U,) O to the signal electrode 7. When passing the gating beam through those portions of the memorizing element, where the recording was made, the recorded charging pattern is modulated, resulting in a decrease in the output current From these sections, up to the value of i g i T °, is diverted to the signal electrode 7. The output read signal igj ,,,, taken from the resistance of the load connected to the circuit of the signal electrode 7 is obtained due to the difference in currents. The efficiency of the memory element is It is plotted in FIG. 3. The solid line indicates the output voltage of the readout signals, taken from the load resistance included in the circuit of the signal electrode 7, according to this ZELT, dotted line - for the known ZELT. The nature of the change in the value of the output read signals and the recorded charge relief is identical. In the known ZELT, the charge relief decreases with time due to the presence of leakage currents arising due to the final conductivity of the surface layer of the MCP channels and the presence of regions with increased conductivity for electric charges near the output sections of the MCP channels . The storage time of the charge relief recorded on the walls of the MCP channels is short. In ZELT in accordance with this invention, the introduction of an additional layer of dielectric 6 leads to a decrease in conductivity near the output sections of channels 5 of the MCP 4, as a result of which the charging relief is maintained longer, i.e. the efficiency of the MCP as a storage element increases. Since the output signal depends on the value of the recorded charge relief (the larger charge relief corresponds to the larger output read signal), then when reading with a raster consisting of n rows (and - 1, ... N), each subsequent raster line reads the charge This relief is reduced in the direction of the reading raster. With the same reading time, the output signal in the known ZELT is smaller than in the ZELT according to this invention. In the well-known ZELT, with an increase in the acquisition time, the output signal becomes indistinguishable from the background noise. In ZELT according to this invention

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by increasing the storage time of the charge relief, i.e. the recovery time of the MCP from the saturation state to the output time increases the readout time (because, which leads to an increase in the scale-time conversion factor. In addition, the maximum recording speed of the signal under investigation is increased in the PLCT according to this invention. This is explained as follows The higher the recording speed, the smaller the number of secondary electrons chosen by the recording beam, the smaller the charge relief recorded on the channel walls of the MCP, and the faster it decreases. In ZELT, according to yes this invention, ceteris paribus, the magnitude of the charge relief

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longer and longer. Therefore, the maximum write speed can be increased, i.e. scan sweep duration -jan reduced. And this, in turn, also leads to an increase in the coefficient of time-scale transformation of information. Thus, in the ZELT according to the present invention, unlike the known ZELT, by introducing an additional dielectric layer, the efficiency of the MCP as a storage element is increased, which results in an increase in the time for reading information. The increase in the storage time of the recorded information in comparison with the known ZELT by 2 orders of magnitude is obtained, which corresponds to an increase in the time of

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Claims (1)

REMEMBERING ELECTRON BEAM TUBE according to ed. No. 695417, characterized in that for the purpose of increasing the accuracy of the information during physical measurements, it additionally contains a dielectric layer located on the advantageous portions of the channels of the microchannel plate from the side facing the signal electrode, and the thickness of the dielectric layer satisfies the condition of the microchannel channel diameter plates. ί 11 14237