阅读说明：本技术 一种设有脉冲光源的液闪测量仪的测量方法 (Measuring method of liquid flash measuring instrument with pulse light source ) 是由 梁金胜 于 2019-11-21 设计创作，主要内容包括：本发明涉及一种设有脉冲光源的液闪测量仪的测量方法,能够获取在脉冲光源的标准脉冲条件下系统的单位时间内的实际计数CPM和对应的TDCR值,对仪器本身带来的电子学误差进行了监测,并提出了两种逻辑判断方式,提高了测量精度和测量效率。(The invention relates to a measuring method of a liquid flash measuring instrument with a pulse light source, which can acquire an actual counting CPM and a corresponding TDCR value in unit time of a system under a standard pulse condition of the pulse light source, monitor electronic errors brought by the instrument, provide two logic judgment modes and improve the measuring precision and the measuring efficiency.)

1. A measuring method of a liquid flash measuring instrument provided with a pulse light source is characterized by comprising the following steps:

step one, establishing electronic original data, namely arranging a pulse light source in a sample bearing unit when a liquid flash measuring instrument is used for the first time, controlling the pulse light source to work under different flash frequencies, and acquiring actual count CPM and triple-double coincidence ratio TDCR values in unit time, which are acquired by a plurality of groups of photomultiplier tubes through the photomultiplier tubes, wherein the pulse light source is a pulse light source carried by a system, the peak flash capacity is less than 20 joules, the pulse width is 0.2-0.8s, and the adjustable range of the flash frequency is 60-100 times/minute;

step two, electronic data monitoring, namely, before each measurement of a standard sample and a sample to be measured, performing electronic data monitoring by the pulse light source in the step one, specifically, turning on the pulse light source, setting a flash frequency, recording current CPM and TDCR values, and storing and recording at least two groups of data;

step three, calculating, namely performing data fitting on the CPM and the TDCR value in the step one to obtain a fitting curve, and calculating a difference value between the last CPM value and the last CPM value in the step two;

step four, a logic judgment step, namely, if the difference value in the step three is zero or is within a set threshold range, directly comparing the TDCR value corresponding to the last CPM value with the TDCR value corresponding to the penultimate CPM value to obtain the difference value of the TDCR values; if the difference value is out of the set threshold range, substituting the CPM value of the last time into the fitting curve to calculate the corresponding TDCR value, and comparing the calculated TDCR value with the TDCR value corresponding to the CPM value of the second time to obtain the difference value of the TDCR values; if the difference value of the two TDCR values is within the set threshold range, the influence of the electronic quenching is not large, and the user can be prompted to continue to measure the sample in the step six, and if the difference value of the TDCR values is outside the set threshold range, the influence of the electronic quenching is large, large measurement errors can be caused, and the user needs to be prompted to check electronic devices and circuits and perform the step five;

step five, electronic data updating, namely after the electronic device and the line are repaired, repeating the step four until the difference value of the TDCR values is within a set threshold range, and storing the TDCR value corresponding to the last CPM value as comparison data for next logic judgment;

and step six, performing a conventional quenching correction step and a to-be-measured sample measurement step.

2. The measurement method according to claim 1, characterized in that: and setting the flash frequency in the second step as the actual counting rate of the current working state of the system.

Technical Field

The invention relates to the measurement of nuclear radiation or X-ray radiation, in particular to the measurement field of X-ray radiation, gamma-ray radiation, corpuscular radiation or cosmic radiation, in particular to the measurement of the radiation intensity of a scintillation detector of which a scintillator is liquid, and particularly relates to a liquid scintillation measurement method with a pulse light source.

Background

The liquid scintillation measurement (liquid scintillation for short) technology is an effective method for measuring low-energy beta rays developed in the early fifties of the twentieth century, and can also be used for detecting other nuclear radiation, such as alpha rays, neutrons, gamma rays and other radiation.

However, in actual measurement, because interference of various factors causes limited measurement accuracy, the main influencing factor is influence of quenching, the quenching is of various types and comprises phase quenching, ionization quenching, concentration quenching, chemical quenching, color quenching and the like, so that the counting efficiency of a sample becomes low (CPM/DPM value becomes small, CPM represents the counting rate of a liquid flash measuring instrument to the sample per minute; DPM represents the absolute decay variable of the sample per minute, and the percentage of the two is called the counting efficiency of the sample). The known quenching correction method produced by various manufacturers in the prior art mainly comprises an internal standard method, an external standard method, an efficiency tracing method and the like, wherein no matter which method is adopted, an index capable of directly or indirectly representing the counting efficiency is essentially found, the index is measurable in a physical sense, when a sample is measured, the current counting efficiency can be known through the measurable index, so that the DPM can be calculated from the CPM of a measured value, the internal standard method belongs to a direct representation mode, but a specially configured liquid scintillation liquid is required, the external standard method must be fitted with a group of indexes related to the quenching degree and the counting efficiency, however, the external standard method cannot simulate the property of the liquid scintillation solution, the error of the measured result is often larger, the reduction of the error and the improvement of the measuring precision become the efforts of technicians in the field, and the known methods, those skilled in the art are generally concerned with keeping the measurement of the standard sample and the measurement of the sample to be measured under the same measurement conditions to reduce errors, but the conditions of the instrument, including the condition of the photoelectric sensor itself, may change from moment to moment, and the art does not have a good monitoring method to correct the possible performance fluctuation errors of the instrument itself, or the art does not find that the problem is actually a significant part of the error generation.

Disclosure of Invention

On the basis of the prior art, a technical team of the applicant researches a liquid flash measuring instrument and a quenching correction method of the liquid flash measuring instrument through a large amount of material resources and manpower input (actually, three available schemes are researched, the application relates to one scheme, the other two schemes are proposed in another scheme, each scheme is divided into main units, and the whole device and the method are arranged).

Aiming at the problems in the prior art, the invention provides a measuring method of a liquid flash measuring instrument with a pulse light source, and mainly aims to improve the precision of the liquid flash measuring method.

In order to achieve the purpose, the invention is realized by the following technical scheme:

the invention mainly relates to a measuring method of a liquid flash measuring instrument with a pulse light source, which comprises the following steps:

step one, establishing electronic original data, namely arranging a pulse light source in a sample bearing unit when a liquid flash measuring instrument is used for the first time, controlling the pulse light source to work under different flash frequencies, and acquiring actual count CPM and triple-double coincidence ratio TDCR values in unit time, which are acquired by a plurality of groups of photomultiplier tubes through the photomultiplier tubes, wherein the pulse light source is a pulse light source carried by a system, the peak flash capacity is less than 20 joules, the pulse width is 0.2-0.8s, and the adjustable range of the flash frequency is 60-100 times/minute;

step two, electronic data monitoring, namely, before each measurement of a standard sample and a sample to be measured, performing electronic data monitoring by the pulse light source in the step one, specifically, turning on the pulse light source, setting a flash frequency, recording current CPM and TDCR values, and storing and recording at least two groups of data;

step three, calculating, namely performing data fitting on the CPM and the TDCR value in the step one to obtain a fitting curve, and calculating a difference value between the last CPM value and the last CPM value in the step two;

step four, a logic judgment step, namely, if the difference value in the step three is zero or is within a set threshold range, directly comparing the TDCR value corresponding to the last CPM value with the TDCR value corresponding to the penultimate CPM value to obtain the difference value of the TDCR values; if the difference value is out of the set threshold range, substituting the CPM value of the last time into the fitting curve to calculate the corresponding TDCR value, and comparing the calculated TDCR value with the TDCR value corresponding to the CPM value of the second time to obtain the difference value of the TDCR values; if the difference value of the two TDCR values is within the set threshold range, the influence of the electronic quenching is not large, and the user can be prompted to continue to measure the sample in the step six, and if the difference value of the TDCR values is outside the set threshold range, the influence of the electronic quenching is large, large measurement errors can be caused, and the user needs to be prompted to check electronic devices and circuits and perform the step five;

step five, electronic data updating, namely after the electronic device and the line are repaired, repeating the step four until the difference value of the TDCR values is within a set threshold range, and storing the TDCR value corresponding to the last CPM value as comparison data for next logic judgment;

and step six, performing a conventional quenching correction step and a to-be-measured sample measurement step.

Further, the basis for setting the flash frequency in the second step is the actual counting rate of the current working state of the system.

Based on the above method concept, a typical liquid flash measuring instrument with a pulse light source comprises: the device comprises a sample bearing unit, a driving unit, a measuring unit, a calculation control unit and a pulse light source; the driving unit comprises a rotating platform and a plurality of driving motors, the sample bearing unit is arranged on the rotating platform, the whole sample bearing unit and one part of the rotating platform are arranged in the shell of the measuring unit, the other part of the rotating platform and the driving motors are arranged outside the shell of the measuring unit, the driving motors are at least two driving motors which are respectively used for driving the rotating platform to rotate and driving the pulse light source to ascend and descend, the rotating platform is communicated with the inside of the sample bearing unit, the pulse light source is arranged in the rotating platform and can be driven to extend into the inside of the sample bearing unit, the top of the pulse light source is of a plane structure, when the pulse light source is completely arranged in the rotating platform, the top of the pulse light source is used as one part of the bottom of the sample bearing unit, and the one part of the bottom and the other part of the bottom of the sample, at least three photomultiplier tubes are arranged in the shell of the measuring unit, and when a sample is placed on the sample bearing unit, the photomultiplier tubes surround the sample; the calculation control unit is connected with the photomultiplier, the pulse light source and the driving motor and is used for controlling the on and off of the pulse light source, collecting the measurement signal of the photomultiplier, calculating and controlling the driving motor to drive.

Furthermore, the pulse light source is a pulse xenon lamp, the peak flashing capacity is less than 20 joules, and the pulse width is 0.2-0.8 s.

Further, the flash frequency of the pulse light source which is a pulse xenon lamp is 60-100 times/minute.

Further, the bottom of the other part of the sample bearing unit is provided with a ring-shaped mark for obviously marking the top area of the pulsed light source and the bottom of the other part of the sample bearing unit.

Compared with the prior art, the invention has the advantages that:

1) influence factors of electronic quenching are often ignored in the prior art, the neglected problem is creatively provided and a monitoring means is provided;

2) the invention provides two logic judgment modes, fitting data are not used every time according to actual conditions, and direct CPM comparison and corresponding TDCR comparison can be carried out, so that the efficiency is improved;

3) the structure and the method of the invention 2 are easy to be combined with the existing structure, the mode of the invention can be used for monitoring the electronic quenching after the existing structure is simply modified, and the invention has wide application prospect.

Drawings

Fig. 1 is a schematic structural diagram of a measuring unit and a calculation control unit of the present invention.

Fig. 2 is the whole structure of the liquid scintillation meter of the invention.

FIG. 3 is a schematic diagram of the top of the pulsed light source of the present invention in cooperation with the bottom of another portion of the sample support unit.

In the figure: 1. the sample bearing unit comprises a sample bearing unit 1.1, the bottom of the other part of the sample bearing unit 2.1, a rotating table driving motor 2.2, a pulse light source driving motor 3, a rotating table 4, a photomultiplier 5, a pulse light source 5.1, the top of the pulse light source 6, a measurement unit shell 7, a calculation control unit 8, a user terminal 9 and an annular mark.

Detailed Description

The present invention is further described with reference to the accompanying drawings, as mentioned in the background art, there are many ways to characterize the quenching degree, and how to suggest the relationship between the characterization parameters and the actual quenching degree by not changing the properties of the sample itself, such as the principle and calculation method of the TDCR value mentioned in the present invention and other commonly used characterization parameters (SCR, SIS, ESR, H value, etc.) not mentioned in the present invention belong to the prior art, the present invention takes TDCR as an example, and not only applies this value, but also other values can be applied, and DPM and CPM, the counting efficiency is also a fixed term in the art and has its known meaning, the abbreviation mentioned in the present invention is a known definition, and will not be described in detail in the present application, and the used standard samples are all common standard samples sold in the market, for example, a series of standard quenching samples are all known types in the art except for special description, the proportions and components thereof are not particularly described.

With reference to fig. 1-3, the liquid flash measuring instrument of the present invention comprises a sample carrying unit (1), a driving unit, a measuring unit (4), a calculation control unit (7), and a pulse light source (5); the driving unit comprises a rotating platform (3) and a plurality of driving motors (2.1, 2.2), the sample bearing unit (1) is arranged on the rotating platform (3), the whole sample bearing unit (1) and one part of the rotating platform (3) are arranged in a shell (6) of the measuring unit, the other part of the rotating platform and the plurality of driving motors (2.1, 2.2) are arranged outside the shell (6) of the measuring unit, the plurality of driving motors are at least two driving motors (2.1, 2.2) which are respectively used for driving the rotating platform (3) to rotate and driving the pulse light source (5) to ascend and descend, the rotating platform (3) and the sample bearing unit (1) are internally communicated, the pulse light source (5) is arranged inside the rotating platform (3), the top part (5.1) of the pulse light source (5) is of a plane structure, and when the pulse light source (5) is completely arranged inside the rotating platform (3), the top part (5.1) of the pulse light source is used as the bottom part of the sample bearing unit (1), said one part of the bottom and the other part of the bottom (1.1) of the sample-carrying unit constitute the complete bottom of the sample-carrying unit, at least three photomultiplier tubes (PM1-PM3) being further arranged in the housing (6) of the measuring unit, the photomultiplier tubes (PM1-PM3) enclosing the sample (S) when the sample (S) is placed on the sample-carrying unit (1); the calculation control unit (7) is connected with the photomultiplier tubes (PM1-PM3), the pulse light source (5) and the driving unit and is used for controlling the adjustment of the pulse light source (5), collecting the measurement signals of the photomultiplier tubes (PM1-PM3), calculating and controlling the driving motors (2.1, 2.2) to drive.

The pulse light source is a pulse xenon lamp, the peak flashing capacity is less than 20 joules, the pulse width is 0.2-0.8s, the flashing frequency is 60-100 times/min, and the pulse xenon lamp is a common pulse xenon lamp sold in the market.

Referring to fig. 3, the bottom of another part of the sample-carrying unit is provided with a ring-shaped mark (9) for clearly identifying the top area of the pulsed light source and the bottom of another part of the sample-carrying unit, so as to prompt a measurer to conveniently operate when the pulsed light source area needs to be avoided.

The invention also relates to an electronic quenching monitoring unit of the liquid flash measuring instrument, which belongs to a part of a calculation control unit of the liquid flash measuring instrument, wherein the part of the control unit can be sold as an independent unit, and the electronic quenching monitoring unit specifically comprises the following components:

a pulse light source control unit for turning on and off the pulse light source and capable of controlling a flash frequency of the pulse light source;

the monitoring data acquisition unit can acquire an actual counting CPM and a corresponding TDCR value of the system in unit time under a standard pulse condition of the pulse light source, and can set different pulse light source flash frequencies from high to low to acquire more than 5 groups of data according to the specific current counting capacity or working state of the system;

the fitting unit is used for fitting the CPM and TDCR values in the monitoring data acquisition unit to obtain a fitting curve, and more than 5 groups of data are usually needed to obtain a better fitting result;

the electronic system monitoring data storage unit is used for storing the actual counting of the electronic system and the corresponding TDCR value under the standard pulse condition of the pulse light source;

the calculating unit can substitute the fitting curve of the fitting unit according to actual counting to calculate the TDCR value;

a logic judgment unit, configured to compare a CPM value newly acquired by the monitoring data acquisition unit with a last CPM value stored in the electronic system monitoring data storage unit under a standard pulse condition of a pulse light source, where the comparison manner is divided into two cases, where the first case is that, if the CPM values are the same or a difference between the CPM values and the last CPM value is within a set threshold range (for example, a difference is within 10%, where the threshold may be flexibly set according to specific needs, and is not particularly limited), a TDCR value corresponding to the newly acquired CPM value is directly compared with a TDCR value corresponding to the last CPM value stored in the electronic system monitoring data storage unit to obtain a TDCR value difference; if the difference value between the two values is out of the set threshold range, calculating the corresponding TDCR value by using the calculating unit for the newly acquired CPM value, and comparing the TDCR value obtained by calculation with the TDCR value corresponding to the last CPM value stored in the electronic system monitoring data storage unit to obtain the difference value of the TDCR values; in both cases, if the difference between the TDCR values is within a set threshold range (for example, within 5%, the threshold herein may be flexibly set according to specific needs, and is not particularly limited), it indicates that the influence of the electronic quenching is not large, and the sample measurement can be continued, whereas if the difference between the TDCR values is outside the set threshold range, it indicates that the influence of the electronic quenching is large, which may cause a large measurement error, and the inspection of the electronic device and the line is required.

The invention also relates to a measuring method of the liquid flash measuring instrument, which comprises the following steps:

step one, establishing electronic original data, namely arranging a pulse light source in a sample bearing unit when a liquid flash measuring instrument is used for the first time, controlling the pulse light source to work under different flash frequencies, and acquiring actual count CPM and triple-double coincidence ratio TDCR values in unit time, which are acquired by a plurality of groups of photomultiplier tubes through the photomultiplier tubes, wherein the pulse light source is a pulse light source carried by a system, the peak flash capacity is less than 20 joules, the pulse width is 0.2-0.8s, and the adjustable range of the flash frequency is 60-100 times/minute;

step two, electronic data monitoring, namely, before measuring a standard sample and a sample to be measured each time, performing electronic data monitoring through the pulse light source in the step one, specifically, turning on the pulse light source, setting a flash frequency according to the actual counting rate of the current working state of the system (according to the actual condition, for example, the flash frequency is set to be more than 80, the corresponding actual counting rate is more than 250000 times), recording the current CPM and TDCR values, and storing and recording at least two groups of data;

step three, calculating, namely performing data fitting on the CPM and the TDCR value in the step one to obtain a fitting curve, and calculating a difference value between the last CPM value and the last CPM value in the step two;

step four, a logic judgment step, namely, if the difference value in the step three is zero or is within a set threshold range, directly comparing the TDCR value corresponding to the last CPM value with the TDCR value corresponding to the penultimate CPM value to obtain the difference value of the TDCR values; if the difference value is out of the set threshold range, substituting the CPM value of the last time into the fitting curve to calculate the corresponding TDCR value, and comparing the calculated TDCR value with the TDCR value corresponding to the CPM value of the second time to obtain the difference value of the TDCR values; if the difference value of the two TDCR values is within the set threshold range, the user can be prompted to continue to measure the sample in the step six by the electronic quenching influence, and if the difference value of the TDCR values is outside the set threshold range, the user can be prompted to carry out the inspection of the electronic device and the circuit and carry out the step five by the electronic quenching influence, the user can be prompted to carry out the measurement error greatly;

step five, electronic data updating, namely after the electronic device and the line are repaired, repeating the step four until the difference value of the TDCR values is within a set threshold range, and storing the TDCR value corresponding to the last CPM value as comparison data for next logic judgment;

and step six, performing a conventional quenching correction step and a to-be-measured sample measurement step. The conventional quenching correction step and the measurement step of the sample to be measured may be the same as those of the prior art and will not be described in detail.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.