Liquid flash measurement method using pulsed photomask

Abstract

The invention relates to a liquid flash measurement method using a pulsed photomask. According to the invention, the actual count CPM and a corresponding TDCR value of a system in unit time under thestandard pulse condition of the pulse light source can be obtained, particularly, the matched photomask is designed for filtering, the material and shape of the photomask are kept basically consistentwith those of a sample container respectively, so that the light waveband received by a photomultiplier in the monitoring state is kept consistent with that received by the photomultiplier in the actual measurement state, and an annular groove positioning mark is specially designed for positioning, so that operation is more accurate, and error prompts of the monitoring system are greatly reduced.

Description

technical field [0001] The present invention relates to the measurement of nuclear radiation or X-ray radiation, specifically the field of measurement of X-ray radiation, γ-ray radiation, microparticle radiation or cosmic ray radiation, and especially relates to the measurement of the radiation intensity of a scintillation detector in which the scintillator is liquid, specifically A liquid scintillation measurement method. Background technique [0002] Liquid scintillation measurement (referred to as liquid scintillation) technology is an effective method for measuring low-energy beta rays developed in the early 1950s, and can also be used to detect other nuclear radiation, for example, it can be used to detect alpha rays, neutrons, gamma Radiation such as Ma ray, liquid scintillation measuring instrument is widely used in many aspects such as industry, agriculture, biology, chemistry, medicine, pharmacy, geology, hydrology, archaeology, environment and so on. [0003] Howe...

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Problems solved by technology

[0003] However, in actual measurement, due to the interference of various factors, the measurement accuracy is limited. The main influencing factor is the influence of quenching. There are many types of quenching, including phase quenching, ionization quenching, concentration quenching, chemical Quenching, color quenching, etc. Quenching, affected by this, leads to lower counting efficiency of the sample (CPM / DPM value becomes smaller, CPM means the count rate per minute of the sample by the liquid scintillation meter; DPM means the sample per minute The absolute number of decays, the percentage of the two is called the counting efficiency of the sample), in actual measurement, the result of direct measurement is CPM, how to accurately obtain DPM from CPM has become the most concerned issue in this field, because usually quenching is the main Influencing factors, so this inversion process is called quenching correction

The known quenching correction methods produced by various manufacturers in the prior art mainly include internal standard method, external standard method, efficiency tracer method, etc. No matter which method is used, it is essentially to find a method that can directly or indirectly characterize and count It is an index of efficiency, and this index is measurable in a physical sense. When measuring a sample, the current counting efficiency can be known through this measurable index, so that DPM can be calculated from the measured value CPM. The internal standard method belongs to direct However, it requires a specially configured liquid scintillation solution. The external standard method must have a set of indicators related to the degree of quenching and counting efficiency to fit it. However, the external standard method cannot simulate the properties of the liquid scintillation solution itself. The results of the measurement have large errors, and reducing the error and improving the measurement accuracy has become the direction of efforts of those skilled in the art. With these known methods, those skilled in the art are usually more concerned about making the measurement of the standard sample and the measurement of the sample to be tested in the same position. However, the conditions of the instrument, including the condition of the photoelectric sensor itself, may change at any time, but there is no good monitoring method in this field to correct the possible performance fluctuation error of the instrument itself, or in this field It is not found that this problem is actually an important part of the error generation

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