SU822068A1 - Pulse-height analyzer - Google Patents

Description

(54) ANALYZER AMPLITUDES OF PULSES

I

The invention relates to nuclear electronics and can be used as part of radiometric devices for detecting radiation.

A pulse amplitude analyzer is known, which contains the amplifier connected in series: and an input driver, the output of which is connected to the inputs of the upper and lower threshold stages, as well as the input of the additional threshold stage; the outputs of the threshold stages are connected to the input of the logical selection stage, with the amplifier input connected to the analyzer's input terminal and the output of the logical selection stage 11 to the output terminal.

However, the discrimination level of the additional threshold cascade is established near the noise level, therefore, the response time of it only slightly differs from the time of the beginning of the growth of the signal under study. An additional threshold cascade produces a pulse, the trailing edge of which in turn forms a pulse passing through the logical selection cascade only if the threshold cascade of the lower level is triggered, but the threshold cascade of the upper level is not triggered.

The time resolution of the described analyzer is determined by the duration of the pulse generated by the additional threshold cascade, and the duration of this pulse cannot be less than the time for which

0 the amplitude of the signal under investigation reaches the maximum or the level of discrimination of the upper threshold box, generating a pulse to prohibit the passage of signals to the output

5 analyzers.

The purpose of the invention is to increase the time resolution.

The goal is achieved by the fact that in the analyzer containing the block

0 logical selection, a threshold element of the lower level, an amplifier connected in series, a shaper of input signals and an additional threshold element, a shaper of standard signals additionally inserted between an additional threshold element and a lower level threshold element, the second threshold element of the lower level, whose input is connected

To the output of the input driver, the logical selection unit is designed as a trigger, inverter and delay element, the input of the delay element and the output of the second threshold element of the lower level are interconnected and connected to the trigger input, the information and installation inputs of which are connected respectively to the outputs the lower level threshold element and the inverter, and the inverter inputs are with the outputs of the delay element and the additional threshold element,

FIG. 1 - a structural diagram of the pulse amplitude analyzer is presented; in fig. 2 - time diagrams.

The analyzer circuit (FIG. 1) contains an amplifier 1, a shaper 2 of input signals, an additional threshold element 3, a shaper 4 standard signals, a threshold element 5 of the lower level, a second threshold element 6 of the lower level, a logical selection unit 7 containing a charge element 8, an inverter 9, trigger 10.

The analyzer works as follows.

The signal under study 11 (Fig. 2), amplified by amplifier 1 and formed by shaper 2, enters an additional threshold element whose discrimination level Vg is established near the noise level. Due to this, the triggering moment of the additional threshold element slightly differs from the time of the beginning rise of the signal 11. The forward edge 12 produced by the threshold element 3, the shaper 4 is started, which forms a standard signal 13 with a leading edge profile similar to the slope of the probe signal, whose amplitude is equal to the upper threshold level /. The initial level of the signal 13 coincides with the level of V. Due to this, the temporal mismatch between the signal under study 11 and the standard signal 13, which occurs due to the discrepancy between the onset of the rise of these signals, is eliminated.

A pulse 12 inverted by an inverter 9 is set to O flip-flop 10.

The investigated 11 and standard 13 signals are received respectively at the inputs of the threshold elements 5 and 6.

The moment of initiation of the threshold element 6 with respect to the threshold element 5 depends on the amplitude of the signal under study 11. It arrives later / if the amplitude of the signal 11 exceeds the lower level V, but

less than the level of v, and earlier if the signal amplitude 11 exceeds the level and, therefore, the level of the standard signal 13.

If the signal 15 generated by the e threshold element 6 passes after the signal 14 generated by the threshold element 5, then the trigger device 10, triggered on the front 0/1, goes into state

Q 1. After a time interval f equal to the time of the leading edge of the signal 15 through the delay element 8, the trigger 10 is again set to the position of O. At the output of the logical selection unit 7, a positive pulse 16 of duration P is formed that is suitable for further processing.

If the signal 15 is Wits before the signal 14, then the absence of the enabling signal on the information

the input of the trigger 10 at the time of impact on its clocked input of the front 0/1 will not trigger the trigger.

5 Introduction to the analyzer of the shaper 4 standard signals and the second threshold element 6 of the lower level, as well as the execution of logical selection block 7 in the form of a device containing trigger 10, inverter 9 and delay element 8, significantly increase the temporal resolution of the analyzer, since amplitude selection signals exceeding the Vg level,

 the moment of reaching the amplitude of the signals of level V, and much earlier at the moment of reaching the level of V.

This makes it possible to increase the frequency load.

0 analyzers, i.e. increasing the number of channels of devices or systems whose pulses are to be studied.

In addition, with such an amplitude selection of input signals, the effect of large amplitude signals on the input stages of the analyzer is excluded.

Claims (1)

Invention Formula Pulse amplitude analyzer containing logic selection block, a lower threshold element connected in series with an amplifier, an input driver and an additional threshold element, characterized in that, in order to increase the resolution by time, the analyzer additionally introduced a shaper of standard signals, connected between an additional threshold element and a threshold element of the lower level, the second threshold element of the lower level7 n, the input of which is connected to the output of the input signal generator, the logical selection unit is made in the form of a trigger, an inverter and a delay element, the input of the delay element and the output of the second threshold element of the lower level are connected - both are connected to the trigger input, information and installation inputs which are connected respectively to the outputs of the threshold element of the lower level of the inverter, and the inputs of the inverter to the outputs of the delay element and the additional threshold element. Sources of information / taken into account in the examination  1, Matveev V.V., Khazanov B.I. Instruments for measuring ionizing radiation. Atomizdat, 1972, p. 393.