K / Ar method dating experiment method without quality correlation

Abstract

The invention provides a K / Ar method dating experiment method without quality correlation. A related test system comprises a controllable excitation X-ray tube, an X-ray energy disperse spectroscopy and a control and data acquisition computer, the method comprises the following steps: firstly, preprocessing a sample to be tested, optimizing components of a test system, then carrying out system test, and finally processing test data. The method has the advantages that the influence of non-uniform contents of K and Ar elements in the sample on dating precision is avoided, dating can be directly carried out for in-situ analysis of samples without Ar isotope interference or extraterrestrial celestial bodies, and Ar isotope measurement does not need to be carried out by other instruments. Compared with the traditional K and Ar discrete dating technology, the method provided by the invention has the advantages of less resource demand, high measurement precision and simple and fast implementation process, and is especially suitable for extraterrestrial celestial body in-situ dating in vacuum environments such as the moon and the asteroid.

Description

Technical Field

[0001] This application belongs to the technical field of dating methods, and specifically relates to a K / Ar dating experimental method without mass correlation. Background Art

[0002] Rock dating is one of the key data for studying the origin of the universe or geological changes. Since the content of K element in rocks is relatively high, it is relatively easy to detect, and the selectivity for samples is not high, so the K / Ar dating method is widely used in geological research. Especially in the in-situ dating technology of exoplanets, the K / Ar method is basically the only feasible dating means. The "Curiosity" Mars rover in the United States used the K / Ar method to achieve in-situ dating of extraterrestrial celestial bodies for the first time in the history of human deep space exploration.

[0003] The K / Ar method usually uses X-ray fluorescence analysis to measure the content of K element. However, due to the extremely low content of Ar in rocks, the conventional X-ray fluorescence analysis method cannot obtain the measurement of Ar content. The measurement of Ar content in the laboratory usually relies on large-scale magnetic analysis mass spectrometers or high-precision quadrupole mass spectrometers. Therefore, the K / Ar dating in the laboratory has a large measurement device, a complex implementation process, and the ratio of K / Ar content in the sample can only be normalized by accurately knowing the mass of the analyzed sample. There are many measurement error factors introduced in the implementation and analysis process, reducing the dating accuracy. Summary of the Invention

[0004] The purpose of this application is to overcome the defects of the prior art, such as a large measurement device, a complex implementation process, and the ratio of K / Ar content in the sample can only be normalized by accurately knowing the mass of the analyzed sample. There are many measurement error factors introduced in the implementation and analysis process, reducing the dating accuracy.

[0005] To achieve the above purpose, this application proposes a K / Ar dating experimental method without mass correlation. The related test system includes:

[0006] A controllable excitation X-ray tube, an X-ray energy spectrometer, and a control and data acquisition computer; wherein,

[0007] The initial position angle between the X-ray beam emission direction of the X-ray tube and the normal direction of the X-ray energy spectrometer detector is maintained at 90 degrees; the X-ray beam emission center position of the X-ray tube and the detector center position of the X-ray energy spectrometer are in the same plane; the X-ray beam emission direction of the X-ray tube and the detector central axis direction of the X-ray energy spectrometer are in the same plane, and this plane is parallel to the normal of the sample to be measured; the size of the sample to be measured is larger than the irradiation size after the X-ray beam of the X-ray tube is limited.

[0008] The control and data acquisition computer is used to control the radiation intensity of the X-ray tube and the X-ray photon energy, and acquire and store the data of the X-ray spectrometer;

[0009] The method includes:

[0010] First, preprocess the sample to be tested, optimize the components of the test system, then conduct system tests, and finally process the test data;

[0011] The system tests include:

[0012] Set the X-ray tube voltage to the set voltage, discretely change the electron current of the X-ray tube at the set voltage, and test the X-ray fluorescence spectrum of one sample for each electron current; measure the K characteristic peak counting rate C k , and the background counting rate C at the Ar characteristic energy Ar , to obtain C k / C Ar ; the background counting rate C at the Ar characteristic energy Ar Take the average of the counting rates at the rising and falling edges of the Ar characteristic peak;

[0013] Discretely change the voltage of the X-ray tube, and discretely change the electron current of the X-ray tube at each voltage. Test the X-ray fluorescence spectrum of one sample for each voltage and each electron current to obtain the dynamic range of C k / C Ar ;

[0014] Rotate the sample counterclockwise, with each rotation angle less than the set angle, and repeat the above process at each angular position;

[0015] Compare the C k / C Ar ratio ranges obtained from the above process, find the experimental conditions with the maximum ratio, restore the layout of the test system to the geometric layout with the maximum ratio and fix it; place the test system in a vacuum environment;

[0016] When the vacuum degree and the vacuum maintenance time reach the set time limit, set the voltage and electron current of the X-ray tube to be consistent with the experimental conditions of the maximum ratio, start the X-ray spectrometer, and continuously collect or intermittently accumulate the peak counts of K above the set quantity;

[0017] The processing of the test data includes:

[0018] Select the range from 1 keV before the Ar characteristic energy peak to the rising edge of the K characteristic peak as the target fitting region; select the Gaussian function as the model, i.e., the signal model, for each characteristic energy peak covered in the target fitting region;

[0019] Select a polynomial of degree 3 to 10 as the model of the background fluorescence spectrum, that is, the background model;

[0020] Directly add the signal model and the background model as the final experimental data fitting model;

[0021]

[0022] Among them, for a selected region, i represents the i-th Gaussian peak in this region; n represents the degree of the polynomial; m represents the number of Gaussian peaks in the selected region; x represents each channel of the X-ray spectrometer corresponding to the selected energy region; a j 、b i 、c i and d i represent the parameters to be fitted; y fit represents the fitting result;

[0023] Before fitting the measured data with the model, standardize the data obtained from the experimental test;

[0024] Select the least squares method to find the best model parameter matching of the data by minimizing the sum of the squares of the errors; through the actual physical meanings of each parameter, determine the parameter values corresponding to the peak position and full width at half maximum of the characteristic energy peak of Ar, define the parameter range corresponding to the peak height of the characteristic energy peak of Ar, the peak positions, peak heights, full widths at half maximum of other characteristic peaks appearing in the target fitting region, and the parameter range of the polynomial, and give the initial values of these parameters; combine the optimized best model parameters, calculate the areas under the peaks of the characteristic energy peaks of Ar and K respectively, and further obtain the ratio of the areas under the peaks of Ar and K;

[0025] Measure a geological standard sample with a known age, obtain the proportionality coefficient k between the known age of this standard sample and the ratio of the areas under the peaks of Ar and K measured, and use this proportionality coefficient k and the ratio of the areas under the peaks of Ar and K elements of the sample to be measured to obtain the age of the sample to be measured.

[0026] As an improvement of the above method, the pretreatment of the sample to be measured includes:

[0027] Sand the surface of the sample to be measured, and then polish the sanded sample;

[0028] Blow the sample under a hot air blower for more than 10 minutes, and set the temperature of the hot air blower to be greater than 200 degrees Celsius.

[0029] As an improvement of the above method, the optimization of the test system components includes:

[0030] Keep the initial position of the angle between the X-ray beam of the X-ray tube and the X-ray energy spectrometer unchanged at 90 degrees, and place the plane of the sample to be measured perpendicular to the irradiation direction of the X-ray beam; adjust the size of the X-ray collimator aperture, the energy of the X-ray, the X-ray intensity, and the tilt angle of the sample to obtain the maximum dynamic range of the K and Ar characteristic peaks; the maximum dynamic range of the K and Ar characteristic peaks is the optimal layout of the test system.

[0031] As an improvement of the above method, the set voltage is 5V.

[0032] As an improvement of the above method, the electron current of the X-ray tube is discretely changed under the set voltage, and the change range of the electron current is from 1 μA to 100 μA.

[0033] As an improvement of the above method, the voltage of the X-ray tube is discretely changed, and the change range of the voltage is from 5 kV to 50 kV.

[0034] As an improvement of the above method, the set angle is 5 degrees.

[0035] As an improvement of the above method, the set period is that the vacuum degree is better than 10 -4 Pa, and the holding time is more than 24 h.

[0036] As an improvement of the above method, the set quantity is 10 7 .

[0037] As an improvement of the above method, the processing of the test data further includes:

[0038] If there are other Ar isotopes in the sample to be measured, use a mass spectrometer to measure the proportion of the Ar isotopes, and combine the measured area ratio of the peaks of Ar and K elements and the proportionality coefficient k to obtain the age of the sample to be measured.

[0039] Compared with the prior art, the advantages of the present application are:

[0040] The method of the present invention uses a set of miniaturized X-ray fluorescence analysis devices with special configurations, which can realize the simultaneous measurement of the K and Ar contents of the dating samples, and can perform multiple repeated measurements on the same micro-region or different regions of the samples, avoiding the influence of the uneven K and Ar element contents of the samples on the dating accuracy. For samples without Ar isotope interference or in-situ analysis of extraterrestrial celestial bodies, direct dating can be carried out without using other instruments to measure Ar isotopes. Compared with the traditional K-Ar discrete dating technology, the present invention has less resource requirements, higher measurement accuracy, and a simple and fast implementation process, and is especially suitable for in-situ dating of extraterrestrial celestial bodies in a vacuum environment such as the moon and asteroids. Description of the Drawings

[0041] Figure 1 Shown is a schematic diagram of the K / Ar dating experiment system without mass correlation;

[0042] Figure 2 Shown is a schematic diagram of the characteristic peaks of K and Ar in the sample under the atmospheric environment;

[0043] Figure 3 Shown is a schematic diagram of the characteristic peaks of K and Ar under the vacuum environment;

[0044] Figure 4 Shown is a comparison diagram of the measured energy spectrum and the fitted energy spectrum after fitting (including the net Ar peak and the background curve);

[0045] Figure 5 Shown is a flowchart for optimizing the high - voltage and electron - current parameters of the X - ray tube under vacuum (at the same layout angle and speed - limiting holes). Specific implementation manners

[0046] The technical solutions of the present application will be described in detail below with reference to the accompanying drawings.

[0047] The present application proposes a K / Ar dating experiment method without mass correlation. By using a set of miniaturized X - ray fluorescence analysis devices with a special configuration, it can simultaneously measure the K and Ar contents of the dating samples, and can also perform multiple repeated measurements on the same micro - region or different regions of the sample, avoiding the influence of uneven K and Ar element contents in the sample on the dating accuracy. For samples without Ar isotope interference or in - situ analysis of extraterrestrial celestial bodies, direct dating can be carried out without using other instruments to measure Ar isotopes. Compared with the traditional separate K and Ar dating technologies, the present invention requires less resources, has high measurement accuracy, and a simple and fast implementation process, and is particularly suitable for in - situ dating of extraterrestrial celestial bodies in vacuum environments such as the moon and asteroids. Without mass correlation means that during the entire sample dating analysis process, the ratio of the areas under the K and Ar peaks is used throughout, and the mass of the sample to be measured does not need to be involved for K / Ar dating. In the test scheme that requires mass correlation, generally, the mass of the sample to be measured needs to be measured to determine the mass contents of K and Ar in the sample.

[0048] A K / Ar dating experiment method without mass correlation proposed by the present invention involves an experimental system including:

[0049] A controllable - excitation X - ray tube, an X - ray energy spectrometer, a sample to be analyzed, a control and data - acquisition computer, and a high - vacuum experimental chamber; the X - ray tube, the X - ray energy spectrometer, and the sample to be analyzed are placed in the vacuum chamber; the control and data - acquisition computer is placed outside the vacuum system. Among them:

[0050] The controllable excitation X-ray tube includes a cold cathode X-ray tube or a hot cathode X-ray tube; the electron current of the X-ray is continuously adjustable within the range of 1 - 1000 μA; the high voltage of the X-ray tube is continuously adjustable within the range of 0.5 - 50 kV; the anode target of the X-ray tube is a tungsten target or a target made of other materials; the X-ray tube is a transmission target or a reflection target; a collimating aperture is added at the ray output end of the X-ray tube, and the size of the collimating aperture is such that the diameter of the ray beam irradiating the sample is less than 5 mm.

[0051] The X-ray energy spectrometer uses a silicon drift detector or a silicon detector, can achieve the measurement of single X-ray photons, and has an energy resolution better than 200 eV. The measured X-ray energy range is not less than 1 - 20 keV, the data count rate ≥ 10 4 counts / s, the number of output energy channels is not less than 1024 channels, and the effective area of the X-ray energy spectrometer detector ≥ 10 mm 2 .

[0052] The control and data acquisition computer is used to control the radiation intensity of the X-ray tube, the X-ray photon energy, and acquire and store the data of the X-ray energy spectrometer.

[0053] The sample to be analyzed is in powder or block form. The powder sample needs to be wrapped with a plastic film or compression molded, and the absorption of the plastic film thickness for Ar and K characteristic rays can be ignored. Whether it is a powder sample or a block sample, the X-ray irradiation surface is a plane, and there is no shape requirement for the non-irradiated surface.

[0054] The high-vacuum experimental chamber provides a high-vacuum environment for testing and analysis. The main purpose is to exclude the measurement interference caused by Ar in the atmospheric environment. If testing in a vacuum environment such as on the moon or an asteroid, a vacuum experimental chamber is not required.

[0055] The layout of this experimental system is as Figure 1 shown.

[0056] The initial position angle between the X-ray beam exit direction and the normal direction of the X-ray energy spectrometer detector is maintained at 90 degrees; the X-ray beam exit center position and the detector center position are on the same horizontal plane; the size of the sample to be measured is larger than the X-ray irradiation size after collimation. The X-ray beam center direction and the detector center axis direction are in the same horizontal plane, and this plane is parallel to the normal of the sample to be measured.

[0057] The K / Ar dating experimental method without mass correlation includes:

[0058] Four processes: sample pretreatment, optimizing the test system layout, system testing, and data processing.

[0059] The sample pretreatment process is to first polish the surface of the sample to be tested with sandpaper, then polish the polished sample, and then place the sample under a hot air blower for more than 10 minutes, with the air gun temperature set above 200 degrees Celsius. The above process is to remove the adsorbed Ar that may exist on the sample surface, and this process is applicable for conducting dating tests in a laboratory environment.

[0060] Optimizing the test system layout is carried out in an atmospheric environment. The layout optimization process includes:

[0061] The initial position of the 90-degree angle between the X-ray beam and the X-ray energy spectrometer remains unchanged, and the plane to be tested of the sample is placed perpendicular to the irradiation direction of the beam, as specifically shown in the Figure 1 attachment. In this initial geometric layout, by adjusting the size of the X-ray collimator aperture, the energy of the X-ray, the X-ray intensity, and the tilt angle of the sample, the maximum dynamic range of the K and Ar characteristic peaks is obtained, and the maximum dynamic range of the K and Ar characteristic peaks is the optimal layout of the test system. Vacuum testing is carried out under the optimal layout.

[0062] As Figure 5 shown, the specific system test process is as follows:

[0063] 1. Set the high voltage of the X-ray tube to 5 kV, and discretely change the electron current of the X-ray tube under high voltage, with the change range from 1 μA to 100 μA. Test the X-ray fluorescence spectrum of one sample for each electron current, as Figure 2 shown. Evaluate the count rate C k of the K characteristic peak, and the background count rate C Ar at the Ar characteristic energy, and obtain C k / C Ar under this high voltage and electron current condition. The background count rate C Ar at the Ar characteristic energy takes the average value of the count rate at the rising edge and the falling edge of the Ar characteristic peak, as specifically shown in the Figure 2 annotation;

[0064] 2. Discretely change the high voltage of the X-ray tube from 5 kV to 50 kV, and discretely change the electron current of the X-ray tube from 1 μA to 100 μA under each high voltage. Test the X-ray fluorescence spectrum of one sample for each high voltage and each electron current, and obtain the dynamic range of C k / C Ar for each X-ray fluorescence spectrum;

[0065] The above experimental process is only for C k / C ArDynamic range measurement operation process: Rotate the sample counterclockwise, with each rotation angle less than 5 degrees, and repeat steps 1 - 2 of the above process at each angular position. The cumulative rotation angle of the sample counterclockwise is about 50 degrees.

[0066] Compare C obtained from the above experimental process k / C Ar ratio range, find the experimental conditions for the maximum value, including the high voltage of the X-ray tube, electron current, sample angle, collimator aperture size, etc., and restore the layout of the experimental device to the geometric layout with the maximum ratio and fix it. Then evacuate to make the vacuum degree of the system better than 10 -4 Pa and maintain it for more than 24 hours to further reduce the small amount of Ar that may be adsorbed on the surface of the sample to be measured during the optimization layout process.

[0067] When the vacuum degree and vacuum maintenance time reach the set limit, set the high voltage of the X-ray tube and the electron current to be the same as the optimized parameter values under atmospheric conditions, start the X-ray energy spectrometer, and continuously collect or intermittently accumulate the peak count of K above 10 7 above, as Figure 3 shown.

[0068] The data processing process includes:

[0069] Data processing uses the method of analyzing the fluorescence spectrum of finite energy channels near the characteristic energies of Ar and K, and estimates the peak areas under the characteristic energy Gaussian peaks of Ar and K respectively. The selected target fitting region covers from 1 keV before the characteristic energy peak of Ar to the rising edge of the K characteristic peak. Select the Gaussian function as the model (signal model) for each characteristic energy peak covered in the target fitting region. To prevent overfitting, select a low-order polynomial of order 3 to 10 as the model (background model) of the background fluorescence spectrum. The direct sum of the signal model and the background model can be used as the final data model. Establish the model as shown in Formula 1. For a selected region, i represents the i-th Gaussian peak in the region. The background model is fitted with an n-order polynomial, and the characteristic energy peak is fitted with a standard Gaussian peak. Among them, n represents the degree of the polynomial selected, m represents the number of Gaussian peaks in the selected region, x represents each channel of the X-ray energy spectrometer corresponding to the selected energy region, and the rest of a j 、b i 、c i 、d i are all parameters to be fitted; y fit represents the fitting result.

[0070]

[0071] Before fitting the measured data with the model, it is also necessary to standardize the data obtained from the experimental test to eliminate the error caused by different dimensions and accelerate the weight convergence speed.

[0072] The least squares method is selected to find the best model parameter matching of the data by minimizing the sum of the squares of the errors. To achieve a more accurate fitting, based on the actual physical meanings of the various parameters, the values of some parameters are determined, the ranges of the remaining parameters are defined, and reasonable initial parameter values are given. In this fitting, specifically: the parameter values corresponding to the peak position and full width at half maximum of the characteristic energy peak of Ar are determined, the parameter range corresponding to the peak height of the characteristic energy peak of Ar, the peak positions, peak heights, full widths at half maximum of other characteristic peaks appearing in the target fitting region, and the parameter range of the polynomial are defined, and the initial values of these parameters are given; combining the optimized best model parameters, the areas under the peaks of the characteristic energy peaks of Ar and K are calculated respectively, as well as the proportionality coefficient of the areas under the peaks of Ar and K. The final fitting result is as Figure 4 shown, where the actual data curve and the fitting curve coincide highly, and the goodness of fit reaches 0.99.

[0073] By measuring geological standard samples with known ages, the proportionality coefficient k between the known ages of the standard samples and the ratios of the areas under the peaks of Ar and K measured is obtained. Using this coefficient k and the ratios of the areas under the peaks of Ar and K of the sample to be analyzed, the age of the analyzed sample can be obtained. If there is no interference from Ar isotopes in the analyzed sample, the age of the analyzed sample can be directly determined using this coefficient. If there are other Ar isotopes in the analyzed sample, then the proportion of Ar isotopes is measured using other mass spectrometers. Combining the measured ratios of the areas under the peaks of Ar and K elements and the coefficient k measured through the standard samples, it is also possible to directly obtain 40 Ar / 40 K without sample mass correlation, thus achieving accurate dating of the sample.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solutions of the present application does not depart from the spirit and scope of the technical solutions of the present application, and they should all be covered within the scope of the claims of the present application.

Claims

1. A K / Ar statutory year experimental method without mass correlation, the relevant test system includes: Controllable excitation X-ray tube, X-ray spectrometer and control and data acquisition computer; among which, The angle between the X-ray beam emission direction of the X-ray tube and the normal direction of the X-ray spectrometer detector is maintained at 90 degrees at the initial position; the X-ray beam emission center position of the X-ray tube and the center position of the X-ray spectrometer detector are on the same plane; the X-ray beam emission direction of the X-ray tube and the central axis direction of the X-ray spectrometer detector are on the same plane, and the plane is parallel to the normal of the sample to be tested; the size of the sample to be tested is larger than the irradiation size after the X-ray beam of the X-ray tube is limited; The control and data acquisition computer is used to control the radiation intensity of the X-ray tube and the energy of X-ray photons, and to acquire and store data of the X-ray spectrometer; The method comprises: First, the samples to be tested are pre-processed, the test system components are optimized, then the system is tested, and finally the test data is processed; The system testing includes: The X-ray tube voltage is set to a set voltage, the electron current of the X-ray tube is discretely changed under the set voltage, and a sample X-ray fluorescence spectrum is tested for each electron current; the K characteristic peak count rate C is measured under the set voltage and electron current. k , and the background count rate C at the Ar characteristic energy Ar , and obtain C under set voltage and electron current k / C Ar ; Background count rate C at Ar characteristic energy Ar Take the average of the counting rate at the rising and falling points of the Ar characteristic peak; The voltage of the X-ray tube is discretely changed, and the electron current of the X-ray tube is discretely changed at each voltage, and a sample X-ray fluorescence spectrum is tested at each voltage and each electron current to obtain the C of each X-ray fluorescence spectrum. k / C Ar Dynamic range; Rotate the sample counterclockwise, with each rotation angle being less than the set angle, and repeat the above process at each angle position; Compare the C obtained by the above process k / C Ar Ratio range, find the experimental conditions of the maximum ratio, restore the layout of the test system to the geometric layout of the maximum ratio and fix it; place the test system in a vacuum environment; When the vacuum degree and vacuum maintenance time reach the set period, the voltage and electron current of the X-ray tube are set to be consistent with the experimental conditions of the maximum ratio, the X-ray energy spectrometer is started, and the peak count of K is continuously collected or intermittently accumulated to be above the set number; The processing of the test data comprises: The target fitting region is selected from 1 keV before the characteristic energy peak of Ar to the rising edge of the characteristic peak of K; the Gaussian function is selected as the model of each characteristic energy peak covered in the target fitting region, that is, the signal model; The 3rd to 10th order polynomials were selected as the model of the background fluorescence spectrum, i.e., the background model; The signal model and the background model are directly added together as the final experimental data fitting model: Where, for a selected region, i represents the i-th Gaussian peak in the region; n represents the polynomial degree; m represents the number of Gaussian peaks in the selected region; x represents the channels of the X-ray spectrometer corresponding to the selected energy region; a j 、b i 、c i and d i represents the parameter to be fitted; y fit represents the fitting result; Before fitting the model to the measured data, the data obtained from the experimental test are standardized; The least squares method is used to find the best model parameter match for the data by minimizing the sum of squares of errors; the parameter values ​​corresponding to the peak position and half-height width of the characteristic energy peak of Ar are determined through the actual physical meaning of each parameter, the parameter range corresponding to the peak height of the characteristic energy peak of Ar, the peak position, peak height, half-height width of other characteristic peaks appearing in the target fitting area, and the parameter range of the polynomial are defined, and the initial values ​​of these parameters are given; combined with the optimized best model parameters, the areas under the peaks of the characteristic energy peaks of Ar and K are calculated respectively, and the ratio of the areas under the peaks of Ar and K is further obtained; A geological standard sample of known age is measured to obtain the proportionality coefficient k between the known age of the standard sample and the ratio of the measured areas under the Ar and K peaks. The age of the sample to be tested is obtained by using the proportionality coefficient k and the ratio of the areas under the Ar and K element peaks of the sample to be tested.

2. The K / Ar dating experimental method without mass correlation according to claim 1, characterized in that: The pretreatment of the sample to be tested comprises: Grind the surface of the sample to be tested with sandpaper, and then polish the ground sample; Place the sample under a hot air blower for more than 10 minutes, and the temperature of the hot air blower is set to be greater than 200 degrees Celsius.

3. The K / Ar dating experimental method without mass correlation according to claim 1, characterized in that: The optimized test system components include: Keep the initial position of the angle of 90 degrees between the X-ray beam of the X-ray tube and the X-ray spectrometer unchanged, and place the sample plane to be tested perpendicular to the irradiation direction of the X-ray beam; adjust the size of the X-ray beam limiting hole, the energy of the X-rays, the X-ray intensity, and the tilt angle of the sample to obtain the maximum dynamic range of the K and Ar characteristic peaks; the maximum dynamic range of the K and Ar characteristic peaks is the optimal layout of the test system.

4. The K / Ar dating experimental method without mass correlation according to claim 1, characterized in that: The set voltage is 5V.

5. The K / Ar dating experimental method without mass correlation according to claim 1, characterized in that: The electron current of the X-ray tube is discretely changed under a set voltage, and the range of the electron current is 1 μA to 100 μA.

6. The K / Ar dating experimental method without mass correlation according to claim 1, characterized in that: The discretely changing voltage of the X-ray tube has a voltage range of 5 kV to 50 kV.

7. The K / Ar dating experimental method without mass correlation according to claim 1, characterized in that: The setting angle is 5 degrees.

8. The K / Ar dating experimental method without mass correlation according to claim 1, characterized in that: The set limit is that the vacuum degree is better than 10 -4 Pa, and the maintenance time is more than 24h.

9. The K / Ar dating experimental method without mass correlation according to claim 1, characterized in that: The set quantity is 10 7 .

10. The K / Ar dating experimental method without mass correlation according to claim 1, characterized in that: The processing of the test data further includes: If other Ar isotopes exist in the sample to be tested, the proportion of Ar isotopes is measured by mass spectrometry, and the age of the sample to be tested is obtained by combining the measured area ratio under the Ar and K element peaks and the proportional coefficient k.

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