SU653645A1

SU653645A1 - Method of measuring dissector electron beam electron-optical spreading spot

Info

Publication number: SU653645A1
Application number: SU752173805A
Authority: SU
Inventors: Тамара Николаевна Китенко; Любовь Дмитриевна Аксенова; Борис Эдуардович Бонштедт; Валерий Николаевич Лукьянов
Original assignee: Предприятие П/Я М-5273
Priority date: 1975-09-15
Filing date: 1975-09-15
Publication date: 1979-03-25

Description

Изобретение относитс к области телевизионных измерений.This invention relates to the field of television measurements.

Известен способ измерений электронноонтического кружка размыти электронного пучка диссектора по переходной характеристике , заключающийс в измерении длины переходной характеристики от уровн 0,1-0,9 фронта нарастани переходной характеристики с последующими расчетными операци ми 1 .The known method of measuring the electron-optical circle of diffusion of the electron beam of the dissector according to the transient characteristic consists in measuring the length of the transient characteristic from the level of 0.1-0.9 fronts of the rise of the transient characteristic with subsequent calculation operations 1.

Однако данный способ измерений вл етс сложным и не обеспечивает достаточной точности измерений.However, this measurement method is complex and does not provide sufficient measurement accuracy.

Целью изобретени вл етс повыщение точности измерений и упрощение измерений.The aim of the invention is to increase measurement accuracy and simplify measurements.

Это доститаетс те.м, что измер ют длину переходной характеристики от уровн 0,1 до уровн 0,9 фронта нарастани при некоторо .м заданном потенциале на ускор ющем электроде диссектора, дополнительно измер ют длину переходной характеристики при тех же уровн х фронта сигнала и потенциале на ускор ющем электроде в два раза меньщем, чем первоначальный, и определ ют размер электронно-оптического кружка размыти по формулеThis is achieved by the fact that the length of the transient characteristic is measured from the level of 0.1 to the level of 0.9 of the rise front at some given potential on the accelerating electrode of the dissector, the transient response length is additionally measured at the same signal front levels and potential on the accelerating electrode is two times smaller than the initial one, and the size of the electron-optical diffuser circle is determined by the formula

А Д/е, аэ V , And D / e, ae V,

где1( и - длины переходной характеристики электрического сигнала;where1 (and are the lengths of the transient response of the electrical signal;

К - А Ua K - A Ua

и, И U2 - потенциалы на ускор ющем электроде диссектора;and, and U2 are the potentials at the accelerating electrode of the dissector;

п - э.мпирический коэффициент.n is the empirical coefficient.

Способ измерени заключаетс в следующем .The measurement method is as follows.

Claims

The optical image of a point object is projected onto a photocathode that forms an electronic image, which is then focused and deflected relative to the cutting hole in the diaphragm and amplified by the secondary electron multiplier of the dissector. In this case, the signal of the dissector has the shape of a hill, possibly with a flat top. In the ideal case, this signal has a sharp increase and decrease. In practice, the characteristics of the increase and decline have a final front. The increase (decline) characteristic is called a transition characteristic. The parameter of the transient response is the length of the transition I, measured on the abscissa axis between the points corresponding to the levels of 0.1 and 0.9 in the portion of the increment front curve. If the diameter of the optical image of a point object in the plane of the photocathode of the dissector is less than the diameter (side) of the hole in the dissector more than twice, the length of transition 1 is determined by the diameter of the optical image do with the diameter of the electron-optical blur circle of the do detector. The factor limiting the resolution of the image amplifier with a magnetic focusing is usually considered to be the resulting blur circle in accordance with the law of addition of dispersions of the component blur circles. Using this, one can imagine the relationship between the transition length and the diameters of the optical and electron-optical circles as follows: + d2. It is also known that the size of the electron-optical circle of blurring on the axis of the device and the potential of the accelerating electrode of the electrovacuum device are connected by a certain relationship from which the size of the circle of blurring can be determined. 4 The invention The method of measuring the electron-optical circle of blur of the electron beam of the dissector according to the transient characteristic of an electrical signal, consists in measuring the length of the transient response of an electrical signal from 0.1 level to 0.9 front level and for a given potential voltage on the accelerator electrode of the dissector, characterized in that, in order to increase the measurement accuracy and simplify the measurements, the length of the transient response of the electrical signal is additionally measured at the same levels fr nta signal and voltage on the accelerating electrode of the dissector, differing at least two times from the voltage during the initial measurement, and determine the size of the electron-optical blur circle by the formula where li and Ij are the transient response characteristics of the electrical signal ;, K (where Uj and Ui are the potentials at the accelerating electrode of the dissector; and p is the empirical coefficient. Sources of information taken into account in the examination 1. U.S. Patent No. 3,610,993, cl. 25--49.5, 17.02.68.