Magnification-adjustable PMT voltage division circuit

Abstract

The invention discloses a magnification-adjustable PMT voltage division circuit comprising a photomultiplier with multiple dynodes. Each dynode is connected with an RC bias circuit which consists of a voltage division resistor and a capacitor which are connected in parallel. The voltage division resistors of two adjacent dynodes are sequentially connected in series. At least one dynode is provided with a photoelectric coupler of which the output end is connected in parallel to the voltage division resistor of the dynode and the input end is connected with the output end of an operational amplifier. According to the magnification-adjustable PMT voltage division circuit provided by the invention, the photoelectric coupler is arranged on one dynode, and the current output of the photoelectric coupler is controlled by the operational amplifier, so that the gain of the PMT can be adjusted conveniently and flexibly. The magnification-adjustable PMT voltage division circuit of the invention is simple in structure, and has the characteristics of stable gain, low power consumption, fast recovery, and the like.

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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