Charge frequency converter

Abstract

The invention provides a front measurement circuit for measuring charge (current) signal and converting the signal into frequency output. A charge frequency converter is mainly characterized in that a current signal input end P1 is connected with an input end of an integration circuit (1) through a resistance R2; an output end of the integration circuit (1) is connected with an input end of a narrow pulse formation circuit (3) through a range discriminating circuit (2); an input end 1 of the narrow pulse formation circuit (3) is respectively connected with an input end of a time-delay circuit (4), an input end of an output pulse shaping circuit (6) and a control end of a first release switch (8); an output end of the time-delay circuit (4) is connected with a release branch through range control and a coupling circuit (5); an input end 2 of the narrow pulse formation circuit (3) is connected with a control end of a second release switch (9); and an output end of the output pulse shaping circuit (6) is connected with a frequency output stage circuit (7). The invention provides a measurement circuit with simple structure and reliable performance for reading signal of beam intensity detector.

Description

technical field [0001] The invention is a front-end measurement circuit for measuring charge (current) signal and converting it into frequency output. Background technique [0002] In the heavy ion cancer treatment device, the real-time monitoring and measuring circuit of the heavy ion beam current is a key part of the device. The heavy ion beam passes through the beam intensity detector (ionization chamber) and induces a weak current signal. By measuring this weak current, real-time monitoring of the beam intensity / irradiation dose can be realized. [0003] Under normal circumstances, since the charge / current signal output by the particle detector is generally relatively small, and the charge / current signal is generally inconvenient to measure directly, the usual method is to convert it into a voltage signal and amplify it, and then the voltage signal Performing ADC sampling and indirectly realizing the measurement of the output current of the detector requires a more comp...

AI Technical Summary

Problems solved by technology

[0003] Under normal circumstances, since the charge / current signal output by the particle detector is generally relatively small, and the charge / current signal is generally inconvenient to measure directly, the usual method is to convert it into a voltage signal and amplify it, and then the voltage signal Performing ADC sampling to indirectly measure the output current of the detector requires a more complicated process and more instruments

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