A pmt voltage divider circuit with adjustable magnification

Abstract

The invention discloses a PMT voltage divider circuit with adjustable magnification. piezoresistors and capacitors, and the voltage dividing resistors between adjacent two stages of dynodes are connected in series in sequence, wherein at least one stage of dynodes is provided with a photocoupler, and the output end of the photocoupler is connected in parallel with the stage dynodes. The input terminal of the optocoupler is connected to the output terminal of the operational amplifier. The adjustable magnification PMT voltage divider circuit provided by the present invention can adjust the gain of PMT conveniently and flexibly by setting a photocoupler at a certain stage of the dynode and using an operational amplifier to control the current output of the photocoupler, and has a simple structure. , has the characteristics of stable gain, low power consumption and fast recovery time.

Description

technical field [0001] The invention relates to a voltage dividing circuit, in particular to a PMT voltage dividing circuit with adjustable magnification. Background technique [0002] The voltage divider circuit of the photomultiplier tube (PMT) currently used mainly includes a resistor network, a classic RC bias circuit, and an improved active configuration circuit (including active components of a triode) on the classic RC bias circuit, but There is no voltage divider circuit that can adjust the PMT gain. [0003] The RC voltage divider circuit is a classic PMT voltage divider circuit, the circuit diagram is as follows figure 1 shown. Its disadvantage is that when the charge output by the PMT becomes larger, there will be a large current on the voltage dividing resistors of the last few stages of the PMT, which will cause the voltage on the dynode to change, thereby affecting the output of the PMT magnification. stability. Therefore, it is only suitable for use in det...

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Problems solved by technology

Its disadvantage is that when the charge output by the PMT becomes larger, there will be a large current on the voltage dividing resistors of the last few stages of the PMT, which will cause the voltage on the dynode to change, thereby affecting the output of the PMT magnification. stability

[0005] Neither of the above two voltage dividers has the function of adjusting the PMT magnification. To adjust the PMT magnification, the only way to adjust the PMT magnification is to adjust the voltage value of -HV. However, the smaller voltage value not only affects the PMT magnification, but also affects Parameters such as transit time make the performance of PMT worse

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