Method and circuit for detecting energy segmentation of specific radioactive nuclide

Abstract

The invention discloses a method and a circuit for detecting energy segmentation of a specific radioactive nuclide. The method is characterized in that a sodium iodide (NaI) crystal and a photomultiplier are used for forming a detector assembly, a high-energy ray is converted to a weak pulse signal, the weak pulse signal is amplified and shaped by a signal amplification circuit into a signal of a certain amplitude to be supplied to a subsequent circuit, the signal after being amplified and shaped is outputted to an upper discrimination threshold and lower discrimination threshold judgment circuit consisting of two low-bias voltage high-speed comparators, a benchmark source is generated by a high-precision low-temperature-drift integration voltage benchmark source circuit, the comparison voltage is supplied to the comparator after being adjusted by a precise potentiometer, and an adjusting potentiometer adjusts the upper discrimination threshold voltage and the lower discrimination threshold voltage. The method and the circuit have the advantages that the hardware is simple and easy, measurement with certain precise can be completed only by a small-sized detector, no large-sized shielding chamber is needed, the cost of the quantitative detection instrument is greatly reduced, and the quantitative detection instrument of the specific nuclide can be purchased by common consumers.

Description

technical field [0001] The invention relates to a method for detecting radionuclide, in particular to a method for detecting specific radionuclide energy segmentation and a circuit thereof. Background technique [0002] In the field of nuclear detection technology, photoelectric conversion detectors are generally used to convert absorbed high-energy rays into weak electronic pulses, which are converted into measurable pulse signals through signal processing technology, and the amplitude of the signal reflects the energy of the rays. To detect the intensity of a specific radionuclide (such as cesium-137, Cs-137), it is necessary to use a multi-channel pulse amplitude analyzer (multi-channel analyzer, MCA) to obtain the energy peak corresponding to the specific radionuclide ( For example, the electron pair effect of cesium-137 can be counted at 662KeV), and the intensity of the nuclide can be obtained according to a certain algorithm. This method extracts some specific energy...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that it needs to use a multi-channel pulse amplitude analyzer to obtain the spectral line of the all-energy segment. The hardware and algorithm are relatively complicated, and a large-scale detector, a large instrument volume, a high-speed hardware detection circuit, and a long detection process are required. , can not collect pulse signals with higher count rate, and is expensive, especially not suitable for occasions that need to quickly measure a specific single nuclide

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