SU1019521A1 - Method of registering working voltage of photodetector power supply - Google Patents

Description

The invention relates to the field of operation of photomultipliers such as photomultipliers (PMTs) and dissectors, and serves to select their operating point when using the photon counting method.

There is a known method for determining the operating mode of a photomultiplier, which consists in measuring the dependence of the output pulse count of the voltage supply and selecting the operating point on the plateau of the obtained counter characteristic 1.

However, this method gives a result, depending on the mode of operation, by registering the output pulses of the photomultiplier, equipment.

11a most closely: it is technically (to the point proposed is a method for determining the operating voltage of the photodetector's power supply, including: measurement of the dark current and the speed of the count: that of the dark pulses of the photodetector depending on the voltage or power.

Sprso.b consists in measuring the dependences of the dark current, the count rate of dark pulses, and the absolute gain of the photocurrent; Capacity from its power supply voltage and the determination of the minimum stability parameter I 2).

The disadvantage of this method; is the complexity of its implementation .. because it involves such a time-consuming operation as the measurement of the absolute coefficient of the photodetector.

The aim of the invention is to simplify the determination of the operating voltage of the power supply ...; .;.:, ..-;

The goal is achieved by the fact that, according to the method for determining the operating voltage, power of the photodetector, on-; measuring the dark current and the count rate of the dark pulses of the photodetector depending on the supply voltage:, measure the transmission coefficient registered by the equipment

while ensuring the stabilization of the average amplitude of single-electron impulses at the amplifier output by the instrumentation, the dependence of the transmission coefficient on the photodetector supply voltage is determined, and the operating voltage of the photodiode jitter is determined as the power supply voltage, corresponding to the minimum value of

t:

where IT is dark current;

and, - dark counting rate

PULSES)

h - transfer coefficient re. gistrirukdayey equipment. Fig, 1 shows the block diagram of the proposed device; in FIG. 2 - determination results

working voltage of the photodetector.

The device comprises an illuminator with a radioluminescent light source 1, flip-down opaque BLIND 2, a head of a photodetector 3, an amplifier 4,; amplitude discriminator 5, electron-counting frequency meter b, nanoammeter 7, multichannel analyzer 8 pulses, power supply 9.

Amplifier 4, amplitude discriminator 5 and electron-counting frequency meter 6 t-type are connected in series to the photodetector output.

4-3-33 .-. , .., -: ..

In addition, a nanoampermeter 7 of type B7-2t is connected to the output of photodetector 3 and a multichannel analyzer 8 of impulses of type AI-256-b, which is used to determine the optimal mode of single-electron pulses of photodetector 3 with each change of supply voltage f, source 9 of type VS7 is connected to the output of amplifier 7 -22.

In accordance with the scheme nano-ammeter 7 measures the current and the frequency meter b - pulse count rate. The second 2 is used to measure the parameters in the dark: ohm mode and in the backlight mode. The input of the nano-ammeter 7 can also be included in the photocathode of the photodetector 3, for which additional measures are taken to prevent isolation breakdown: as a result of measurements and processing of experimental data by a known method, the dependence shown in curve 10 (Fig. 2) was obtained, and the proposed method is on curve 11 (Fig. 2). Comparison of curves 10 and 11 shows. that the proposed method has an additional advantage, since the resulting extremum is more acute, the operating voltage can be determined with higher accuracy. At E. TOM, it is most expedient to work with a modulated luminous flux; then, in the absence of light, the dependences on the Yiwu and If voltage are measured, and when the light is supplied, Vj and I. This eliminates the need to double-pass the entire voltage range of the photodetector power supply and allows you to automate the measurement process.

The simplification of the known method in accordance with the invention is achieved through the use of the actual procedure for measuring the absolute gain, which usually consists in measuring the ratio of the anode current to the photocathode current, differing from each other by 6-9 times. In the proposed method, instead of measuring the absolute gain factor}, a simpler measurement of the gain of the amplifier, inversely proportional as a result of stabilization of the average amplitude of one-electron pulses to the absolute gain of the photodetector, is used. In the proposed method, the determination of the magnitude of the amplification is performed with greater accuracy, since the stabilization of the average amplitude is performed according to the maximum of the single-electron current.

The owner of the jugger is a convenient frame, the behavior of which is not affected by the loss of electrons in the input sensor of the photodetector and by-processes, Ezne does not usually make mistakes in determining the gain.

The invention can be used in the electrovacuum industry when certifying odioelectronic photodetectors and in laboratory practice for improvement.) 1Orch, properties of photodetectors.

Naples nutrition (fkt8.

Claims (1)

METHOD OF DETERMINING WORKING Voltage Power photodetectors, comprising measuring the dark current and dark pulses of light speed photodetectors depending on n & n- ¹ maskers supply of t n and h and w - u, and D with I · in that, in order to simplify determination of the working photodetector supply voltage, measure the transmission coefficient of the recording equipment while ensuring stabilization of the average amplitude of one <electronic pulses at the output of the amplifier, the recording equipment, determine the dependence of the transmission coefficient on the voltage the current of the photodetector, and the operating voltage of the photodetector is defined as the supply voltage corresponding to the minimum value of the value where 1 _t is the dark current; and _t is the count rate of dark pulses; k is the transmission coefficient of the recording equipment. SU .. 1019521 A