A hybrid K-edge absorption-X-ray fluorescence analysis method and device

Abstract

The present invention discloses a mixed K-edge absorption-X-ray fluorescence analysis method, which uses X-rays to irradiate a sample to be tested, so that the sample to be tested produces uranium K-edge absorption, and excites L-series characteristic fluorescence of uranium and plutonium in the sample to be tested, and obtains the absorption spectrum of uranium in the sample to be tested according to the X-rays after the uranium K-edge absorption of the sample to be tested, and obtains the uranium concentration according to the absorption spectrum and the X-ray blank spectrum; obtains the L-series fluorescence peak area relationship of uranium and plutonium in the sample to be tested according to the L-series characteristic fluorescence of uranium and plutonium in the sample to be tested, thereby obtaining the uranium / plutonium concentration ratio, and then obtaining the plutonium concentration of the sample to be tested. The mixed K-edge absorption-X-ray fluorescence analysis method of the present invention can break the limitation of the scope of application, effectively improve the accuracy of the analysis result, and effectively reduce the influence of X-ray scattering. The present invention also provides a mixed K-edge absorption-X-ray fluorescence analysis device.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear industry, and in particular relates to a mixed K-edge absorption-X-ray fluorescence analysis method and equipment. Background Art

[0002] In the nuclear industry, the analysis of uranium and plutonium concentrations in liquid feed is extremely important. The above analysis can not only reflect the process operation status, but also provide important data support for the adjustment of process parameters. However, due to the large differences in uranium and plutonium concentrations in different samples produced at different process points, and the presence of multiple process sampling points, large sample volume, and high analytical accuracy requirements, sample analysis poses great challenges.

[0003] For the analysis of uranium and plutonium in typical 1AF samples, isotope dilution mass spectrometry or hybrid K-edge absorption-X-ray fluorescence analysis technology is usually used internationally. Isotope dilution mass spectrometry requires precise sampling, spike addition, separation and other operations of the sample. The process is complicated and time-consuming, and it is difficult to meet the time limit requirements of sample analysis. It is generally used as a calibration method and is not suitable for daily routine analysis. Hybrid K-edge absorption-X-ray fluorescence analysis technology can directly analyze the sample without chemical separation. The analysis speed is fast, the operation is relatively simple, and it can be applied to high-radioactivity (>10 13 Bq / L) samples, and this method is also used in post-processing plants at home and abroad.

[0004] However, the existing hybrid K-edge absorption-X-ray fluorescence analysis technology also has certain application limitations. In the existing technology, X-ray fluorescence analysis is used to obtain the concentration relationship of uranium and plutonium through the K-series fluorescence peaks of uranium and plutonium. Affected by X-ray scattering, a "big bulge" will be generated near the K-series fluorescence peaks of uranium and plutonium, making the spectrum peak background very high. It is difficult to measure the effective spectrum peaks of low-concentration uranium and plutonium samples. Figure 1 The figure shows the K fluorescence analysis measurement spectrum in the prior art. The large bulge in the figure is caused by high-energy X-ray scattering and cannot be eliminated. The large bulge will cause the background (i.e., baseline) of the spectrum to be too high. Therefore, if the concentration of uranium and plutonium is low, the intensity of the characteristic fluorescence is not enough and is annihilated by the background, and the fluorescence peak cannot be seen in the figure. Especially when the uranium concentration is high but the plutonium concentration is low (below about 1g / L), it is difficult to observe the fluorescence peak of plutonium. Even if the spectrum peak can be generated, the statistical error is too large due to the low count, and the result is inaccurate.

[0005] Therefore, the existing hybrid K-edge absorption-X-ray fluorescence analysis technology is more suitable for samples with a uranium content ranging from 150g / L to 250g / L and a uranium / plutonium ratio of 80-150. When the types of components processed by the process are different, the uranium / plutonium ratio (concentration ratio) is higher or the uranium and plutonium content is lower, it is difficult to obtain accurate analysis results. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a hybrid K-edge absorption-X-ray fluorescence analysis method in view of the above-mentioned deficiencies in the prior art, which can effectively reduce the influence of X-ray scattering, break the limitation of application scope, and effectively improve the accuracy of analysis results. The present invention also provides a hybrid K-edge absorption-X-ray fluorescence analysis device.

[0007] The present invention provides a hybrid K-edge absorption-X-ray fluorescence analysis method, comprising:

[0008] Next steps:

[0009] The sample to be tested is irradiated with X-rays to make the sample to be tested produce uranium K edge absorption and stimulate L series characteristic fluorescence of uranium and plutonium in the sample to be tested;

[0010] Obtaining the absorption spectrum of uranium in the sample to be tested according to the X-rays absorbed by the uranium K boundary of the sample to be tested;

[0011] According to the L-series characteristic fluorescence of uranium and plutonium in the sample to be tested, the L-series fluorescence peak area relationship of uranium and plutonium in the sample to be tested is obtained;

[0012] The uranium concentration of the sample to be tested is obtained according to the absorption spectrum of uranium in the sample to be tested and the blank spectrum of X-rays;

[0013] Obtaining a first uranium / plutonium concentration ratio of the sample to be tested according to the L-series fluorescence peak area relationship between uranium and plutonium in the sample to be tested;

[0014] A first plutonium concentration of the sample to be tested is obtained according to the uranium concentration of the sample to be tested and a first uranium / plutonium concentration ratio of the sample to be tested.

[0015] Preferably, the sample to be tested is irradiated with X-rays to stimulate K-series characteristic fluorescence of uranium and plutonium in the sample to be tested; the method further comprises the following steps:

[0016] According to the K-series characteristic fluorescence of uranium and plutonium in the sample to be tested, the K-series fluorescence peak area relationship of uranium and plutonium in the sample to be tested is obtained;

[0017] Obtaining a second uranium / plutonium concentration ratio of the sample to be tested according to the K series fluorescence peak area relationship between uranium and plutonium in the sample to be tested;

[0018] Obtaining a second plutonium concentration of the sample to be tested according to the uranium concentration of the sample to be tested and a second uranium / plutonium concentration ratio of the sample to be tested;

[0019] When the first uranium / plutonium concentration ratio is greater than the set ratio, the first plutonium concentration of the sample to be tested is taken as the plutonium concentration value of the sample to be tested;

[0020] When the first uranium / plutonium concentration ratio is not greater than the set ratio, the first plutonium concentration / the second plutonium concentration of the sample to be tested is taken as the plutonium concentration value of the sample to be tested.

[0021] Preferably, the second uranium / plutonium concentration ratio of the sample to be tested is obtained according to the K series fluorescence peak area relationship between uranium and plutonium in the sample to be tested, specifically referring to: α2 Characteristic peaks and K of plutonium α1 The second uranium / plutonium concentration ratio of the sample to be tested is obtained based on the characteristic peak area relationship.

[0022] Preferably, the first uranium / plutonium concentration ratio of the sample to be tested is obtained according to the L series fluorescence peak area relationship between uranium and plutonium in the sample to be tested, specifically referring to: α Characteristic peaks and L of plutonium α The first uranium / plutonium concentration ratio of the sample to be tested is obtained by the characteristic peak area relationship, and the L α Characteristic peaks include L α1 Characteristic peaks and L α2 Characteristic peak, L α1 Characteristic peak area and L α2 The sum of the characteristic peak areas is L α Characteristic peak area.

[0023] Preferably, when obtaining the absorption spectrum of uranium in the sample to be tested based on the X-rays after being absorbed by the uranium K boundary of the sample to be tested, the following steps are also performed: starting from the time when the X-rays reach the high pressure set value and ending when the measurement time reaches the set time, the original level spectrum of the X-ray energy that does not pass through the sample to be tested within the time range is obtained as the blank spectrum of the X-rays.

[0024] The present invention also provides a mixed K-edge absorption-X-ray fluorescence analysis device, comprising an X-ray emitting device, a K absorption detection device, an L fluorescence detection device and an analysis device, wherein the X-ray emitting device is used to emit X-rays to irradiate a sample to be tested, so that the sample to be tested produces uranium K edge absorption, and excites L-series characteristic fluorescence of uranium and plutonium in the sample to be tested, the K absorption detection device is used to obtain an absorption spectrum of uranium in the sample to be tested according to the X-rays after uranium K edge absorption of the sample to be tested, the L fluorescence detection device is used to obtain the L-series fluorescence peak area relationship of uranium and plutonium in the sample to be tested according to the L-series characteristic fluorescence of uranium and plutonium in the sample to be tested, and the analysis device is electrically connected to the K absorption detection device and the L fluorescence detection device, and is used to obtain the uranium concentration of the sample to be tested according to the absorption spectrum of uranium in the sample to be tested and the blank spectrum of X-rays, and to obtain a first uranium / plutonium concentration ratio of the sample to be tested according to the L-series fluorescence peak area relationship of uranium and plutonium in the sample to be tested, and to obtain a first plutonium concentration of the sample to be tested according to the uranium concentration of the sample to be tested and the first uranium / plutonium concentration ratio of the sample to be tested.

[0025] Preferably, the device further comprises a K fluorescence detection device, the X-ray emitting device can also excite the K series characteristic fluorescence of uranium and plutonium in the sample to be tested by irradiating the sample to be tested with X-rays, the K fluorescence detection device is used to obtain the K series fluorescence peak area relationship of uranium and plutonium in the sample to be tested according to the K series characteristic fluorescence of uranium and plutonium in the sample to be tested, and the analysis device is also electrically connected to the K fluorescence detection device, and the analysis device is used to obtain the K series fluorescence peak area relationship of uranium and plutonium in the sample to be tested according to the K series fluorescence peak area relationship of uranium and plutonium in the sample to be tested. The second uranium / plutonium concentration ratio is used to obtain the second plutonium concentration of the sample to be tested according to the uranium concentration of the sample to be tested and the second uranium / plutonium concentration ratio of the sample to be tested, and when the first uranium / plutonium concentration ratio and / or the second uranium / plutonium concentration ratio is greater than a set ratio, the first plutonium concentration of the sample to be tested is taken as the plutonium concentration value of the sample to be tested; when the first uranium / plutonium concentration ratio and / or the second uranium / plutonium concentration ratio is not greater than the set ratio, the first plutonium concentration / second plutonium concentration of the sample to be tested is taken as the plutonium concentration value of the sample to be tested.

[0026] Preferably, the emission direction of the X-ray emitting device points to the sample to be tested, and an acute angle is formed between the direction of the line connecting the receiving end of the K fluorescence detection device and the sample to be tested and the emission direction of the X-ray emitting device.

[0027] Preferably, a collimator is provided in front of the emitting end of the X-ray emitting device, and the X-rays emitted by the X-ray emitting device and the connection line between the receiving end of the K fluorescence detection device and the sample to be tested all pass through the collimator. A collimator is provided in the direction of the connection line between the receiving end of the K fluorescence detection device and the sample to be tested, and the collimator is closer to the receiving end of the K fluorescence detection device relative to the collimator. The collimator is provided with a first collimator hole at a position corresponding to the connection line between the receiving end of the K fluorescence detection device and the sample to be tested, which is used to converge the K-series characteristic fluorescence of uranium and plutonium in the sample to be tested and then enter the K fluorescence detection device through the collimator. The collimator is provided with a second collimator hole at a position corresponding to the connection line between the X-ray emitting device and the sample to be tested, which is used to converge the X-rays and irradiate the sample to be tested.

[0028] Preferably, the equipment also includes a blank detection device, the X-ray emitting device is arranged on one side of the sample to be tested, and the blank detection device and the K absorption detection device are arranged on the other side of the sample to be tested, the connection line between the X-ray emitting device and the receiving end of the K absorption detection device passes through the sample to be tested, and the connection line between the X-ray emitting device and the receiving end of the blank detection device does not pass through the sample to be tested, the blank detection device is used to start from the time when the X-ray reaches the high voltage set value and end when the measurement time reaches the set time, and obtain the original level spectrum of X-ray energy according to the X-ray that has not passed through the sample to be tested, the analysis device is also electrically connected to the blank detection device, and is used to use the original level spectrum of X-ray energy as the blank spectrum of X-rays, so as to obtain the uranium concentration of the sample to be tested according to the absorption spectrum of uranium in the sample to be tested and the blank spectrum of X-rays.

[0029] Preferably, a collimator is provided in front of the receiving end of the blank detection device and the receiving end of the K absorption detection device, and the X-rays emitted by the X-ray emitting device enter the receiving ends of the two through the collimator. An adjustment plate is also provided in front of the receiving end of the K absorption detection device for adjusting the intensity of the X-rays after being absorbed by the uranium K boundary of the sample to be tested, and the adjustment plate is closer to the sample to be tested than the collimator in front of the receiving end of the K absorption detection device.

[0030] Preferably, the emission direction of the X-ray emitting device points to the sample to be tested, and an acute angle is formed between the direction of the line connecting the receiving end of the L fluorescence detection device and the sample to be tested and the emission direction of the X-ray emitting device.

[0031] Preferably, a diffraction crystal is also provided in the direction of the connection between the receiving end of the L fluorescence detection device and the sample to be tested, and a baffle is provided inside the diffraction crystal, which is perpendicular to the direction of the connection and is used to block the radiation of the sample to be tested and part of the X-rays scattered by the X-ray emitting device.

[0032] Preferably, the X-ray emitting device, K absorption detection device and L fluorescence detection device are all covered with a shielding body on the outside to shield the divergent X-rays and stray light. The shielding body is made of tungsten-nickel-iron alloy, so that the characteristic fluorescence of tungsten in the shielding body is stimulated under X-ray irradiation, which is used for passive energy calibration and spectrum stabilization.

[0033] Preferably, the equipment also includes a shielding cover and a measuring cavity, wherein the shielding cover is arranged on the outside of the X-ray emitting device, the K absorption detection device, the L fluorescence detection device and the sample to be tested, and is used to shield the β and γ rays of the sample to be tested, and the measuring cavity is arranged in the shielding cover, and the cover is arranged on the outside of the sample to be tested, so that the sample to be tested is airtightly isolated from other devices, and a sample transmission interface is provided on the measuring cavity, which is used to communicate with an external chamber, so that the sample transmission system can transmit the sample to be tested between the measuring cavity and the chamber, and the shielding cover is provided with an avoidance opening at the position of the sample transmission interface corresponding to the measuring cavity.

[0034] The mixed K-edge absorption-X-ray fluorescence analysis method of the present invention uses X-rays to irradiate the sample to be tested to stimulate the L-series characteristic fluorescence of uranium and plutonium in the sample to be tested, and obtains the concentration relationship of uranium and plutonium through the L-series fluorescence peaks of uranium and plutonium. Compared with the traditional analysis system that only analyzes the concentration relationship of the two through the K-series fluorescence peak, the concentration range of the analyzed sample can be expanded. When the uranium / plutonium concentration ratio is greater than 150, the L-series fluorescence peak analysis can obtain more accurate results than the K-series fluorescence analysis, because there will be no "big bulge" in the L-series fluorescence spectrum, that is, the scattering of high-energy X-rays will not interfere with the background of the L-series fluorescence spectrum peak, and the gamma and beta rays in the highly radioactive sample will not interfere with the background. Therefore, when the concentration of plutonium is low or the concentration difference between uranium and plutonium is large, a clear and accurate fluorescence peak can still be observed in the spectrum, thereby obtaining an accurate analysis result, and expanding the concentration range of the analyzed sample.

[0035] The analysis method of the present invention breaks through the current application limitations by adopting the above-mentioned setting scheme. The measurement range of uranium is 1 mg / L to 400 g / L, and the measurement range of plutonium is 1 mg / L to 60 g / L. For mixed samples containing uranium and plutonium, samples with a uranium concentration of ≥200 g / L and a uranium / plutonium concentration ratio of ≤700 / 1 can all obtain good accuracy, with RSD≤0.2%. It can be seen that compared with the prior art, not only the analysis results are more accurate, but also the application range of the mixed K-edge absorption-X-ray fluorescence analysis method is greatly broadened. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a K fluorescence analysis measurement spectrum in the prior art;

[0037] Figure 2 is a schematic structural diagram of a hybrid K-edge absorption-X-ray fluorescence analysis device in Example 2 of the present invention;

[0038] Figure 3 is a schematic diagram of the connection structure of the measurement cavity of the hybrid K-edge absorption-X-ray fluorescence analysis device in Example 2 of the present invention;

[0039] Figure 4 1 is another schematic diagram of the connection structure of the measuring cavity of the hybrid K-edge absorption-X-ray fluorescence analysis device in Example 3 of the present invention.

[0040] In the figure: 1. X-ray emitting device; 11. Collimator; 2. K absorption detection device; 21. Adjustment plate; 3. L fluorescence detection device; 31. Diffraction crystal; 4. Shielding cover; 5. Measuring cavity; 51. L fluorescence exit window; 52. Measuring position; 53. Sample to be measured; 6. Blank detection device; 7. Collimator; 8. K fluorescence detection device; 9. Shielding body. DETAILED DESCRIPTION

[0041] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the present invention.

[0042] In the description of the present invention, it should be noted that the terms "upper", "lower" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience and simplification of the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0043] In the description of the present invention, the terms “first”, “second” and “third” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connect", "set", "install", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0045] Example 1

[0046] The hybrid K-edge absorption-X-ray fluorescence analysis method of this embodiment can use the analysis equipment in Example 2, and the method specifically includes the following steps:

[0047] The sample 53 to be tested is irradiated with X-rays to make the sample 53 to be tested produce uranium K edge absorption and stimulate L series characteristic fluorescence of uranium and plutonium in the sample 53 to be tested;

[0048] Obtaining an absorption spectrum of uranium in the sample 53 to be tested according to the X-rays absorbed by the uranium K boundary of the sample 53 to be tested;

[0049] According to the L-series characteristic fluorescence of uranium and plutonium in the sample 53 to be tested, the L-series fluorescence peak area relationship of uranium and plutonium in the sample 53 to be tested is obtained;

[0050] Obtaining the uranium concentration of the sample 53 to be tested according to the absorption spectrum of uranium in the sample 53 to be tested and the blank spectrum of X-rays;

[0051] Obtaining a first uranium / plutonium concentration ratio of the sample 53 to be tested according to the L-series fluorescence peak area relationship between uranium and plutonium in the sample 53 to be tested;

[0052] The first plutonium concentration of the sample 53 to be tested is obtained according to the uranium concentration of the sample 53 to be tested and the first uranium / plutonium concentration ratio of the sample 53 to be tested.

[0053] The hybrid K-edge absorption-X-ray fluorescence analysis method of the present embodiment obtains the concentration relationship between uranium and plutonium through the L-series fluorescence peaks of uranium and plutonium. Compared with the traditional analysis system in which the concentration relationship between the two is analyzed only through the K-series fluorescence peak, the concentration range of the analysis sample can be expanded. When the uranium / plutonium concentration ratio is greater than 150, the L-series fluorescence peak analysis can obtain more accurate results than the K-series fluorescence analysis, because there will be no "big bulge" in the L-series fluorescence spectrum, that is, the scattering of high-energy X-rays will not interfere with the background of the L-series fluorescence spectrum peak, and the γ and β rays in the highly radioactive sample will not interfere with the background. Therefore, when the plutonium concentration is low or the concentration difference between uranium and plutonium is large, a clear and accurate fluorescence peak can still be observed in the spectrum, thereby obtaining an accurate analysis result, thereby expanding the concentration range of the analysis sample.

[0054] The present analysis method has broken through the current application limitations by adopting the above-mentioned setting scheme. The measurement range for uranium is 1 mg / L to 400 g / L, and the measurement range for plutonium is 1 mg / L to 60 g / L. For mixed samples containing uranium and plutonium, samples with a uranium concentration of ≥200 g / L and a uranium / plutonium concentration ratio of ≤700 / 1 can all obtain good accuracy, with RSD≤0.2%. It can be seen that compared with the existing technology, not only the analysis results are more accurate, but also the application scope of the mixed K-edge absorption-X-ray fluorescence analysis method is greatly broadened.

[0055] In this embodiment, since the sample 53 to be tested is irradiated with X-rays, K-series characteristic fluorescence of uranium and plutonium in the sample 53 to be tested can also be stimulated, the method in this embodiment further includes the following steps:

[0056] According to the K-series characteristic fluorescence of uranium and plutonium in the sample 53 to be tested, the K-series fluorescence peak area relationship of uranium and plutonium in the sample 53 to be tested is obtained;

[0057] Obtaining a second uranium / plutonium concentration ratio of the sample 53 to be tested according to the K-series fluorescence peak area relationship between uranium and plutonium in the sample 53 to be tested;

[0058] Obtaining a second plutonium concentration of the sample 53 to be tested according to the uranium concentration of the sample 53 to be tested and the second uranium / plutonium concentration ratio of the sample 53 to be tested;

[0059] When the first uranium / plutonium concentration ratio is greater than the set ratio, the first plutonium concentration of the sample 53 to be tested is taken as the plutonium concentration value of the sample 53 to be tested;

[0060] When the first uranium / plutonium concentration ratio is not greater than the set ratio, the first plutonium concentration / the second plutonium concentration of the sample 53 to be tested is taken as the plutonium concentration value of the sample 53 to be tested.

[0061] In this embodiment, when the uranium content ranges from 150 g / L to 250 g / L, the set ratio is 150. During detection, when the uranium / plutonium concentration ratio is in a range below 150, or in a conventional range of 80-150, the (first / second) uranium / plutonium concentration ratio obtained by K-series characteristic fluorescence and L-series characteristic fluorescence analysis is generally very different, and the plutonium concentrations finally obtained by the two methods are also very different, so the first plutonium concentration / second plutonium concentration can be selected as the final plutonium concentration value of the sample 53 to be tested, and the two can also be used to corroborate each other. When the uranium / plutonium concentration ratio is in a range greater than 150, the result obtained by the L-series characteristic fluorescence analysis is more reliable, so at this time the first plutonium concentration of the sample 53 to be tested is selected as the plutonium concentration value of the sample 53 to be tested.

[0062] Since the concentrations of uranium and plutonium in samples at different process points in the process are different, the radioactivity of samples at different process points is different. The hybrid K-edge absorption-X-ray fluorescence analysis method currently used in the field is generally used to analyze highly radioactive samples, and the concentrations of uranium and plutonium in other medium or low radioactive samples are measured by other analysis methods. The hybrid K-edge absorption-X-ray fluorescence analysis method of this embodiment can be used for analysis not only of highly radioactive samples, but also of medium or low radioactive samples, because it can simultaneously use K-series fluorescence and L-series fluorescence for analysis. Therefore, it can be used for analysis of various sample concentrations and samples, and can take the most reliable value according to the size of the concentration ratio, so it can be applied to various sample concentrations and sample analysis requirements.

[0063] According to the common knowledge in this field:

[0064] Uranium K α1 The peak energy is 98.422keV, K α2 Peak energy 94.649keV;

[0065] K of Plutonium α1 The peak energy is 103.3keV, K α2 Peak energy 99.168keV;

[0066] Uranium L α1 The peak energy is 13.612keV, L α2 Peak energy 13.437keV;

[0067] Plutonium L α1 The peak energy is 14.276keV, L α2 Peak energy 14.082keV.

[0068] Among the conventional analysis methods currently used in the field, K series fluorescence analysis uses uranium K α1 and plutonium K α1 peak to establish a relationship, but it can be seen that the K of plutonium α2 The peak energy and the K α1The energies of the peaks are very close (that is, their positions in the spectrum are very close), and the resolution of the detector in the existing technology cannot separate the two peaks. Therefore, during the analysis, the K α2 Summit interference uranium K α1 peaks, which leads to certain deviations in the results.

[0069] In this embodiment, the second uranium / plutonium concentration ratio of the sample 53 to be tested is obtained according to the relationship between the K series fluorescence peak areas of uranium and plutonium in the sample 53 to be tested, which specifically refers to: α2 Characteristic peaks and K of plutonium α1 The characteristic peak area relationship is used to obtain the second uranium / plutonium concentration ratio of the sample 53 to be tested. That is, the K fluorescence analysis used in the method of this embodiment uses the K α2 K α1 Peak can avoid the above interference and effectively improve the accuracy of the results.

[0070] Since the resolution of the existing L fluorescence detectors on the market is not enough to detect L α1 Characteristic peaks and L α2 The characteristic peaks are separated because the energy difference between the two is really small and only one peak can be seen on the spectrum. Therefore, in this embodiment, the first uranium / plutonium concentration ratio of the sample 53 to be tested is obtained according to the L series fluorescence peak area relationship of uranium and plutonium in the sample 53 to be tested, which specifically refers to: according to the L series fluorescence peak area relationship of uranium in the sample 53 to be tested, the first uranium / plutonium concentration ratio of the sample 53 to be tested is obtained. α Characteristic peaks and L of plutonium α The characteristic peak area relationship is used to obtain the first uranium / plutonium concentration ratio of the sample 53 to be tested. α Characteristic peaks include L α1 Characteristic peaks and L α2 Characteristic peak, L α1 Characteristic peak area and L α2 The sum of the characteristic peak areas is L α Characteristic peak area.

[0071] In this embodiment, when obtaining the absorption spectrum of uranium in the sample 53 to be tested based on the X-rays after being absorbed by the uranium K boundary of the sample 53 to be tested, the following steps are also performed: starting from the time when the X-rays reach the high pressure set value (that is, the value that meets the detection requirements is used as the starting point), the measurement time reaches the set time and ends (that is, when the analysis process is completed is used as the end point), and the original level spectrum of the X-ray energy that does not pass through the sample 53 to be tested within the time range is obtained as the blank spectrum of the X-rays.

[0072] In a conventional analysis system, the measurement of the blank spectrum and the measurement of the sample 53 to be tested are not performed at the same time period, that is, time-sharing measurement, which may be that after the sample 53 to be tested is measured, the sample 53 to be tested is taken out and then the same analysis process as the sample 53 to be tested is performed to measure the blank spectrum, or the blank spectrum is measured before the sample 53 is measured. However, since X-rays may fluctuate at different times, the influence of such fluctuations is not considered when the sample 53 to be tested and the blank spectrum are measured in time.

[0073] In this embodiment, a real-time blank spectrum is obtained while measuring the sample 53 to be tested, that is, the original spectrum of X-ray energy is obtained by X-rays that have not passed through the sample 53 to be tested, so as to eliminate the influence of the fluctuation of the original X-ray energy during the time-sharing blank measurement. Therefore, even if the original X-ray fluctuates, it will be reflected in the real-time blank spectrum. Therefore, the real-time blank spectrum obtained in this embodiment is more accurate than the time-sharing blank spectrum, is completely synchronized with the analysis process, and has a better correction effect. After obtaining the blank spectrum, the sample absorption spectrum and the blank spectrum need to be used together for data processing, and the process of subsequent data processing is the same as the existing conventional processing technology.

[0074] Example 2

[0075] like Figure 2 As shown, the hybrid K-edge absorption-X-ray fluorescence analysis device of this embodiment can be used to implement the analysis method in Example 1. The device includes an X-ray emitting device 1, a K absorption detection device 2, an L fluorescence detection device 3 and an analysis device. The X-ray emitting device 1 is used to emit X-rays to irradiate the sample 53 to be tested, so that the sample 53 to be tested produces uranium K edge absorption, and stimulates the L series characteristic fluorescence of uranium and plutonium in the sample 53 to be tested. The K absorption detection device 2 is used to obtain the absorption spectrum of uranium in the sample 53 to be tested according to the X-rays after the uranium K edge absorption of the sample 53 to be tested. The L fluorescence detection device 3 is used to obtain the L fluorescence spectrum according to the L series characteristic fluorescence of uranium and plutonium in the sample 53 to be tested, and then obtain the L series fluorescence peak area relationship of uranium and plutonium in the sample 53 to be tested.

[0076] The analysis device is electrically connected to the K absorption detection device 2 and the L fluorescence detection device 3, and is used to obtain the uranium concentration of the sample 53 to be tested based on the absorption spectrum of uranium in the sample 53 to be tested and the blank spectrum of X-rays, and to obtain a first uranium / plutonium concentration ratio of the sample 53 to be tested based on the relationship between the L-series fluorescence peak areas of uranium and plutonium in the sample 53 to be tested, and to obtain a first plutonium concentration of the sample 53 to be tested based on the uranium concentration of the sample 53 to be tested and the first uranium / plutonium concentration ratio of the sample 53 to be tested.

[0077] In this embodiment, the L fluorescence detection device 3 is used to obtain the concentration relationship between uranium and plutonium through the L series fluorescence peaks of uranium and plutonium. Compared with the traditional analysis system that only analyzes the concentration relationship between the two through the K series fluorescence peak, the L fluorescence detection device 3 can expand the concentration range of the analysis sample. When the uranium / plutonium concentration ratio is greater than 150, the L series fluorescence peak analysis can obtain more accurate results than the K series fluorescence analysis, because there will be no "big bulge" in the L series fluorescence spectrum, that is, the scattering of high-energy X-rays will not interfere with the background of the L series fluorescence spectrum peak, and the γ and β rays in the highly radioactive sample will not interfere with the background. Therefore, when the plutonium concentration is low or the concentration difference between uranium and plutonium is large, a clear and accurate fluorescence peak can still be observed in the spectrum, thereby obtaining an accurate analysis result, thereby expanding the concentration range of the analysis sample.

[0078] The analysis equipment of this embodiment has broken the current application limitations by adopting the above-mentioned setting scheme. Its measurement range for uranium is 1 mg / L~400 g / L, and its measurement range for plutonium is 1 mg / L~60 g / L. For mixed samples containing uranium and plutonium, samples with uranium concentration ≥200 g / L and uranium / plutonium concentration ratio ≤700 / 1 can all obtain good accuracy, RSD≤0.2%. It can be seen that compared with the prior art, not only the analysis results are more accurate, but also the application scope of the mixed K-edge absorption-X-ray fluorescence analysis equipment is greatly broadened.

[0079] In this embodiment, the X-ray emitting device 1 is an X-ray tube, the rated tube voltage of the X-ray tube is not less than 160kV, the rated continuous operating power is not less than 1.6kW, and a water cooling device and a high-voltage generating device are also provided to provide continuous and stable high-energy primary X-rays to the analysis equipment. During the analysis process, the X-ray tube voltage is set to 150kV, the current is 10mA, the tungsten target, and the X-ray tube is cooled by circulating cooling water. This cooling method and the water cooling device used are relatively conventional and will not be described in detail here. The X-ray tube is provided with a high-voltage protection function. The high voltage can only be started when the X-ray tube water cooler is operating normally and the X-ray tube temperature is within the normal range. When the measurement is completed, the X-ray tube high voltage is automatically reduced to a low-power standby state, which can increase the service life of the X-ray tube. The measurement time of the analysis equipment is set to 1000s.

[0080] In this embodiment, the hybrid K-edge absorption-X-ray fluorescence analysis equipment also includes a K fluorescence detection device 8. The X-ray emitting device 1 can also excite the K-series characteristic fluorescence of uranium and plutonium in the sample 53 to be tested by irradiating the sample 53 with X-rays. The K fluorescence detection device 8 is used to obtain the K-series fluorescence peak area relationship of uranium and plutonium in the sample 53 to be tested based on the K-series characteristic fluorescence of uranium and plutonium in the sample 53 to be tested.

[0081] The analysis device is also electrically connected to the K fluorescence detection device 8. The analysis device is used to obtain a second uranium / plutonium concentration ratio of the sample 53 to be tested based on the relationship between the K series fluorescence peak areas of uranium and plutonium in the sample 53 to be tested, and to obtain a second plutonium concentration of the sample 53 to be tested based on the uranium concentration of the sample 53 to be tested and the second uranium / plutonium concentration ratio of the sample 53 to be tested.

[0082] And, when the first uranium / plutonium concentration ratio and / or the second uranium / plutonium concentration ratio is greater than the set ratio, the first plutonium concentration of the sample to be tested 53 is taken as the plutonium concentration value of the sample to be tested 53;

[0083] When the first uranium / plutonium concentration ratio and / or the second uranium / plutonium concentration ratio is not greater than the set ratio, the first plutonium concentration / the second plutonium concentration of the sample 53 to be tested is taken as the plutonium concentration value of the sample 53 to be tested.

[0084] In this embodiment, the ratio is set to 150. During the test, when the uranium / plutonium concentration ratio is within the range of 80-150, the (first / second) uranium / plutonium concentration ratio obtained by the K series characteristic fluorescence and the L series characteristic fluorescence analysis is generally very small in difference, and the plutonium concentrations finally obtained by the two methods are also very small in difference, so the first plutonium concentration / second plutonium concentration can be selected as the final plutonium concentration value of the sample 53 to be tested, and the two can also be used to corroborate each other. When the uranium / plutonium concentration ratio is within the range of greater than 150, the result obtained by the L series characteristic fluorescence analysis is more reliable, so at this time the first plutonium concentration of the sample 53 to be tested is selected as the plutonium concentration value of the sample 53 to be tested.

[0085] Since the concentrations of uranium and plutonium in samples at different process points in the process are different, the radioactivity of samples at different process points is different. The hybrid K-edge absorption-X-ray fluorescence analysis equipment currently used in the field is generally used to analyze highly radioactive samples, and the concentrations of uranium and plutonium in other medium or low radioactive samples are measured by other analysis methods. The hybrid K-edge absorption-X-ray fluorescence analysis equipment of this embodiment can use K-series fluorescence and L-series fluorescence for analysis at the same time, so it can not only be used for highly radioactive samples, but also for the analysis of medium or low radioactive samples. It can take the most reliable value according to the size of the concentration ratio, so it can be applicable to various sample concentrations and sample analysis requirements.

[0086] Furthermore, the three measuring branches of K absorption detection device 2, K fluorescence detection device 8 and L fluorescence detection device 3 can be operated independently or jointly: K absorption detection device 2 can be operated alone, K absorption detection device 2 and K fluorescence detection device 8 can be operated jointly, K absorption detection device 2 and L fluorescence detection device 3 can be operated jointly, K absorption detection device 2, K fluorescence detection device 8 and L fluorescence detection device 3 can be operated jointly, L fluorescence detection device 3 can be operated alone, and K fluorescence detection device 8 can be operated alone, which is specifically determined according to the range of uranium and plutonium concentrations in the sample to be tested and the analysis requirements of the sample.

[0087] The analysis equipment of this embodiment can realize direct and simultaneous analysis of uranium and plutonium in radioactive samples, and can analyze dissolved solutions of different types of components or other highly radioactive solutions. It has a wide concentration range for measuring uranium and plutonium, high measurement precision, and can be adapted to automatic analysis or chamber analysis, with strong flexibility.

[0088] In this embodiment, the emission direction of the X-ray emission device 1 points to the sample to be tested 53, and an acute angle is formed between the direction of the line connecting the receiving end of the K fluorescence detection device 8 and the sample to be tested 53 and the emission direction of the X-ray emission device 1. Let the acute angle be n, and the smaller the angle of n is, the more conducive it is to reduce the influence of the scattering background on the measurement, improve the measurement accuracy, and at the same time increase the peak area count and peak-to-background ratio of the characteristic peak, thereby improving the detection efficiency.

[0089] In this embodiment, a collimator 11 is provided in front of the emitting end of the X-ray emitting device 1. The X-rays emitted by the X-ray emitting device 1 and the connection line between the receiving end of the K fluorescence detection device 8 and the sample to be tested 53 all pass through the collimator 11. A collimator 7 is provided in the direction of the connection line between the receiving end of the K fluorescence detection device 8 and the sample to be tested 53. The collimator 7 is closer to the receiving end of the K fluorescence detection device 8 than the collimator 11.

[0090] Collimation holes of different sizes but not penetrating the collimation sheet 11 are provided on the collimation sheet 11, wherein the collimation sheet 11 is provided with a first collimation hole at a position corresponding to the connection between the receiving end of the K fluorescence detection device 8 and the sample 53 to be tested, which is used to converge the K series characteristic fluorescence of uranium and plutonium of the sample 53 to be tested and then enter the K fluorescence detection device 8 through the collimator 7, and the collimation sheet 11 is provided with a second collimation hole at a position corresponding to the connection between the X-ray emitting device 1 and the sample 53 to be tested, which is used to converge the X-rays and irradiate the sample 53 to be tested. The collimation sheet 11 is made of Ag or Cd material, which can filter out the emitted and scattered primary X-rays at the same time, absorb the low-energy X-rays below 50keV, and make the X-ray intensity in the high-energy region at a reasonable level, which is conducive to obtaining a sample spectrum with good morphology on the one hand, and further reduce the background baseline of the spectrum on the other hand.

[0091] In this embodiment, the primary X-rays generated by the X-ray emitting device 1 pass through the collimating sheet 11 and the measuring cavity 5 and then irradiate the sample 53 to be tested. After being absorbed by the sample 53 to be tested, the primary X-rays pass through the other side wall of the measuring cavity 5 and the adjusting sheet 21 and enter the K absorption detection device 2 after passing through the collimator 7. The K absorption detection device 2 obtains the absorption spectrum of uranium in the sample 53 to be tested. The analysis device can obtain the accurate uranium concentration of the sample 53 to be tested through the preset concentration calibration.

[0092] The K-series characteristic fluorescence generated by the sample 53 to be tested under the irradiation of X-rays penetrates the measuring cavity 5 and passes through the collimator 11, then passes through the collimator 7, and is finally received by the K fluorescence detection device 8. The K fluorescence detection device 8 detects the K fluorescence of the uranium K α2 and plutonium K α1 The characteristic fluorescence peak area is used to obtain the K series fluorescence peak area relationship between uranium and plutonium, thus avoiding the conventional method of K series fluorescence peak area relationship between plutonium and uranium. α2 Fluorescence interference with uranium K α1 Fluorescence.

[0093] In this embodiment, the hybrid K-edge absorption-X-ray fluorescence analysis equipment also includes a blank detection device 6, the X-ray emitting device 1 is arranged on one side of the sample to be tested 53, the blank detection device 6 and the K absorption detection device 2 are arranged on the other side of the sample to be tested 53, the line connecting the receiving ends of the X-ray emitting device 1 and the K absorption detection device 2 passes through the sample to be tested 53, that is, the receiving end of the K absorption detection device 2 is directly opposite to the emitting end of the X-ray emitting device 1, the line connecting the X-ray emitting device 1 and the receiving end of the blank detection device 6 does not pass through the sample to be tested 53, and the angle p between the emitting end of the X-ray emitting device 1 and the receiving end of the blank detection device 6 in the horizontal plane is 170°.

[0094] The blank detection device 6 is used to obtain the primary spectrum of X-ray energy based on the X-rays that have not passed through the sample 53 to be tested (i.e., primary X-rays), starting from the time when the X-rays reach the high voltage set value and terminating the measurement time when the X-rays reach the set time. The analysis device is also electrically connected to the blank detection device 6, and is used to use the primary spectrum of X-ray energy as the blank spectrum of X-rays, thereby obtaining the uranium concentration of the sample 53 to be tested based on the absorption spectrum of uranium in the sample 53 to be tested and the blank spectrum of X-rays.

[0095] After the primary X-rays are emitted, they directly penetrate the measuring cavity 5 and enter the blank detection device 6 without passing through the sample 53 to be tested. The blank detection device 6 operates at all times during the measurement cycle, with the time when the X-ray high voltage reaches the set value, that is, the value that meets the detection requirements of the K absorption detection device 2, as the starting point, and the time when the measurement time reaches the set value, that is, after the analysis process is completed, as the end point. The primary spectrum of the primary X-ray energy within the time range is recorded as the real-time blank spectrum to eliminate the influence of the primary X-ray energy fluctuation during the time-sharing blank measurement.

[0096] In a conventional analysis system, the measurement of the blank spectrum and the measurement of the sample 53 to be tested are not performed at the same time period, that is, time-sharing measurement, which may be that after the sample 53 to be tested is measured, the sample 53 to be tested is taken out and then the same analysis process as the sample 53 to be tested is performed to measure the blank spectrum, or the blank spectrum is measured before the sample 53 is measured. However, since X-rays may fluctuate at different times, the influence of such fluctuations is not considered when the sample 53 to be tested and the blank spectrum are measured in time.

[0097] In this embodiment, a real-time blank spectrum is obtained by the blank detection device 6 while measuring the sample 53 to be tested, that is, the original-level spectrum of the X-ray energy is obtained by the X-rays that have not passed through the sample 53 to be tested. Therefore, even if the original-level X-rays fluctuate, it will be reflected in the real-time blank spectrum. Therefore, the real-time blank spectrum obtained in this embodiment is more accurate than the simultaneous blank spectrum, and is completely synchronized with the analysis process, and its correction effect is better. After obtaining the blank spectrum, the sample absorption spectrum and the blank spectrum need to be used together for data processing, and the process of the subsequent data processing is the same as the existing conventional processing technology.

[0098] In this embodiment, collimators 7 are provided in front of the receiving ends of the blank detection device 6 and the K absorption detection device 2. The X-rays emitted by the X-ray emission device 1 enter the receiving ends of the two through the collimators 7. An adjustment piece 21 is also provided in front of the receiving end of the K absorption detection device 2 for adjusting the intensity of the X-rays after being absorbed by the uranium K boundary of the sample 53 to be tested. The adjustment piece 21 is closer to the sample 53 to be tested than the collimator 7 in front of the receiving end of the K absorption detection device 2. The adjustment piece 21 is provided at the front end of the collimator 7 of the K absorption detection device 2. The adjustment piece 21 is made of stainless steel or iron. After the intensity of the X-rays absorbed by the sample 53 to be tested is adjusted by the adjustment piece 21, it can still have a suitable count after passing through the collimator 7 to avoid affecting the analysis results.

[0099] In this embodiment, the emission direction of the X-ray emission device 1 points to the sample to be tested 53, and an acute angle is formed between the direction of the line connecting the receiving end of the L fluorescence detection device 3 and the sample to be tested 53 and the emission direction of the X-ray emission device 1. Let the acute angle be m, and the smaller the angle of m is, the more conducive it is to reduce the influence of the X-ray scattering background on the measurement, improve the measurement accuracy, and at the same time increase the peak area count and peak-to-background ratio of the characteristic peak, thereby improving the detection efficiency.

[0100] In this embodiment, the X-ray emitting device 1, the L fluorescence detection device 3 and the K fluorescence detection device 8 are all arranged on the same side of the sample to be tested 53, wherein the K fluorescence detection device 8 shares the collimating plate 11 with the X-ray emitting device 1, so the K fluorescence detection device 8 is closer to the X-ray emitting device 1 than the L fluorescence detection device 3. In this embodiment, the angle n is 30° and the angle m is 60°, and a smaller angle may be selected depending on the application environment and installation conditions. In addition, the L fluorescence detection device 3 and the K fluorescence detection device 8 may be placed on both sides of the X-ray emitting device 1 respectively according to the conditions of the actual application environment, so that the angle m can be further reduced and can be set to ≤30°.

[0101] In this embodiment, a diffraction crystal 31 is also provided in the direction of the connection between the receiving end of the L fluorescence detection device 3 and the sample 53 to be tested. A baffle is provided inside the diffraction crystal 31, which is perpendicular to the connection direction and is used to block the radiation (including α rays and part of β and γ rays) of the sample 53 to be tested and part of the X-rays scattered by the X-ray emission device 1. That is, the problem of radioactive interference of the sample 53 to be tested is solved, and the detection limit is reduced. The L series fluorescence is obliquely incident on the inner wall of the diffraction crystal 31, and after being diffracted by the diffraction crystal 31, it is emitted to the L fluorescence detection device 3. After the diffraction crystal 31 is set, the background baseline of the L fluorescence spectrum obtained by the L fluorescence detection device 3 is further reduced, and since most of the interference is also shielded, the accuracy of the analysis result can be further improved.

[0102] The L series characteristic fluorescence generated by the sample 53 to be tested under the stimulation of X-rays passes through the L series fluorescence exit window 51 on the measuring cavity 5, passes through the diffraction crystal 31, and is finally received by the L series fluorescence detection device 3. The L series fluorescence detection device 3 obtains the L series fluorescence peak area relationship of uranium and plutonium. Specifically, the L series fluorescence detection device 3 obtains the L series fluorescence peak area relationship of uranium and plutonium. α Characteristic fluorescence peak area.

[0103] In this embodiment, the exterior of the X-ray emitting device 1, the K absorption detection device 2, the L fluorescence detection device 3, the K fluorescence detection device 8 and the blank detection device 6 are all covered with a shielding body 9, and collimation holes of different sizes are provided on the shielding body 9. The shielding body 9 can be used to shield scattered X-rays and stray light, reduce the radiation impact on each device and personnel, and reduce background noise. The emitting end of the X-ray emitting device 1 is embedded in the shielding body 9, and the receiving ends of the detectors such as the K absorption detection device 2, the L fluorescence detection device 3, the K fluorescence detection device 8 and the blank detection device 6 are also embedded. Inside the shielding body 9, the shielding body 9 is made of tungsten-nickel-iron alloy (of which tungsten accounts for 90%), so that the characteristic fluorescence of tungsten in the shielding body 9 is stimulated under X-ray irradiation. The characteristic fluorescence intensity of tungsten is very strong and does not interfere with the measurement of the characteristic fluorescence peak of the target, so it can be used for passive energy calibration and spectrum stabilization. Compared with the traditional analysis system, there is no need to set up a calibration source separately, which reduces the investment. In addition, since the calibration source will decay over time and affect the calibration, the characteristic fluorescence of tungsten in the shielding body 9 is used for calibration and spectrum stabilization in this embodiment, which will not change over time and has better stability and reliability.

[0104] In this embodiment, the device further includes a shielding cover 4 and a measuring cavity 5. The shielding cover 4 is arranged outside the X-ray emitting device 1, the K absorption detection device 2, the L fluorescence detection device 3 and the sample to be tested 53, and is used to shield the β and γ rays of the sample to be tested 53. The measuring cavity 5 is arranged in the shielding cover 4, and the cover is arranged outside the sample to be tested 53, so that the sample to be tested 53 is airtightly isolated from other devices, ensuring that the aerosol of the sample to be tested 53 will not diffuse out of the measuring cavity 5. A measuring position 52 is arranged in the measuring cavity 5, and the sample to be tested 53 is placed in the measuring position 52. The side wall of the measuring cavity 5 is provided with an L fluorescence exit window 51 at the position corresponding to the connection between the receiving end of the L fluorescence detection device 3 and the sample to be tested 53. The L fluorescence exit window 51 is made of light materials such as boron carbide, PE, and PEEK, so that the L series characteristic fluorescence can be effectively transmitted. A sample transmission interface is provided on the measuring cavity 5 for communicating with an external chamber, so that the sample transmission system can transmit the sample 53 to be measured between the measuring cavity 5 and the chamber. The shielding cover 4 is provided with an avoidance opening at the position of the sample transmission interface corresponding to the measuring cavity 5, so as to avoid the sample transmission system.

[0105] The above-mentioned external chamber can be a hot chamber, a shielded chamber, a glove box, a work box, etc. Figure 3 As shown, one side of the measuring cavity 5 of the hybrid K-edge absorption-X-ray fluorescence analysis equipment is combined with the chamber, and the whole is an airtight structure, which at least meets the level 3 chamber sealing requirements. The sample transmission interface and the chamber can be welded and sealed, or can be sealed by sealing gaskets such as graphite, copper, and EPDM. Personnel complete the pretreatment operation of the sample 53 to be tested in the chamber through mechanical arms, gloves, etc., and then transfer the sample 53 to the measuring position 52 of the measuring cavity 5 through the sample transmission system. The sample transmission system can be manual transfer or automatic transfer combined with other auxiliary tools. After the measurement is completed, the sample 53 to be tested at the measuring position 52 is returned to the chamber for subsequent analysis and processing.

[0106] like Figure 4 As shown, an interface with the sample transmission system can also be opened at the top of the measuring chamber 5. The interface can be welded and sealed, or it can be sealed by a flange and a sealing gasket. After the measuring chamber 5 is connected to the sample transmission system, the whole is an airtight structure. The sample 53 to be tested is loaded in a sample bottle and transmitted from the sample transmission system to the sample measurement position 52 of the measuring chamber 5. Then the analysis system starts measuring. After the measurement is completed, the sample bottle is returned to the sending position of the sample transmission system for subsequent processing. The sample transmission system can be connected to other processing chambers, etc.

[0107] The detection devices of the hybrid K-edge absorption-X-ray fluorescence analysis equipment designed in combination with the chamber are distributed in other positions of the measurement cavity 5 and do not interfere with the chamber. Among them, the X-ray emission device 1 and the K absorption detection device 2 are respectively located on both sides of the measurement cavity 5, and the emission end of the primary X-ray irradiating the sample 53 to be tested and the receiving end of the K absorption detection device 2 are at an angle of 180° in the horizontal plane, that is, the two are directly opposite; the K fluorescence detection device 8 and the L fluorescence detection device 3 are located on the same side of the measurement cavity 5, and the receiving ends of the K fluorescence detection device 8 and the L fluorescence detection device 3 are at an acute angle with the primary X-ray emission end in the horizontal plane, which reduces the influence of the scattered background on the measurement, and at the same time increases the peak area count and peak-to-background ratio of the characteristic peak, thereby improving the detection efficiency; the blank detection device 6 and the K absorption detection device 2 are located on the other side of the measurement cavity 5, and the emission end of the primary X-ray irradiating the sample 53 to be tested and the receiving end of the blank detection device 6 are at an obtuse angle in the horizontal plane.

[0108] In this embodiment, each detection device and detector also includes a refrigeration device, which can use electric refrigeration or liquid nitrogen refrigeration. The data collected by each detection device and detector is pre-amplified, and then through AD digital-to-analog conversion and digital shaping. Based on the shaped pulse, amplitude identification is performed to obtain data related to the pulse signal, energy, and time.

[0109] The hybrid K-edge absorption-X-ray fluorescence analysis equipment of this embodiment irradiates the sample with high-energy X-rays to generate uranium K-edge absorption, and simultaneously excites K-series and L-series characteristic fluorescence of uranium and plutonium, obtains the uranium concentration based on the uranium K-edge absorption, obtains an accurate uranium / plutonium concentration ratio by analyzing the K-series and L-series characteristic fluorescence, and further obtains the plutonium concentration in the sample, and simultaneously corrects the blank to eliminate the influence of energy fluctuation of the primary X-rays, thereby further improving the measurement accuracy.

[0110] The analytical equipment of this embodiment expands the concentration range of uranium and plutonium analysis, significantly improves the applicability of the equipment, and significantly improves the accuracy of analytical measurement; in addition, its structure is simple, and key components such as X-ray tubes and detectors are easy to disassemble and assemble without destroying the sealing of the equipment, and has good safety. The equipment can adapt to different application environments and can be matched with hot chambers, glove boxes, sample transmission systems, etc.

[0111] The equipment of this embodiment can be used for the determination of typical 1AF samples. In addition to typical 1AF samples, there are many other process points that need to be analyzed for uranium and plutonium concentrations. There are high radioactive samples, medium and low radioactive samples, samples with relatively high uranium and plutonium concentrations, and samples with relatively low uranium and plutonium concentrations. There are samples that only measure uranium, and samples that only measure plutonium. There are many types of samples. The existing conventional method will select different other analysis equipment according to the specific samples to be measured. Because this embodiment combines L-series fluorescence analysis, it can measure more types of samples (medium and low radioactive samples can also be measured), and the concentration range of samples that can be measured is also wider (because L-series fluorescence analysis is more advantageous for low concentrations, so the concentration of analysis is expanded), and a set of equipment can be used to complete the determination of various situations.

[0112] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A hybrid K-edge absorption-X-ray fluorescence analysis method, characterized in that: The following steps are involved: The sample to be tested (53) is irradiated with X-rays to make the sample to be tested (53) produce uranium K edge absorption and stimulate L-series characteristic fluorescence of uranium and plutonium in the sample to be tested (53); It can also excite the K-series characteristic fluorescence of uranium and plutonium in the sample to be tested (53); Obtaining an absorption spectrum of uranium in the sample (53) to be tested based on X-rays absorbed by the uranium K boundary of the sample (53) to be tested; obtaining a peak area relationship of L-series fluorescence of uranium and plutonium in the sample (53) to be tested based on L-series characteristic fluorescence of uranium and plutonium in the sample (53); Obtaining the uranium concentration of the sample to be tested (53) according to the absorption spectrum of uranium in the sample to be tested (53) and the blank spectrum of X-rays; Obtaining a first uranium / plutonium concentration ratio of the sample to be tested (53) based on the L-series fluorescence peak area relationship between uranium and plutonium in the sample to be tested (53); Obtaining a first plutonium concentration of the sample to be tested (53) according to the uranium concentration of the sample to be tested (53) and a first uranium / plutonium concentration ratio of the sample to be tested (53); According to the K-series characteristic fluorescence of uranium and plutonium in the sample (53) to be tested, the K-series fluorescence peak area relationship of uranium and plutonium in the sample (53) to be tested is obtained; Obtaining a second uranium / plutonium concentration ratio of the sample to be tested (53) based on the relationship between the K-series fluorescence peak areas of uranium and plutonium in the sample to be tested (53); Obtaining a second plutonium concentration of the sample to be tested (53) according to the uranium concentration of the sample to be tested (53) and a second uranium / plutonium concentration ratio of the sample to be tested (53); When the first uranium / plutonium concentration ratio is greater than a set ratio, taking the first plutonium concentration of the sample to be tested (53) as the plutonium concentration value of the sample to be tested (53); When the first uranium / plutonium concentration ratio is not greater than the set ratio, the first plutonium concentration / the second plutonium concentration of the sample to be tested (53) is taken as the plutonium concentration value of the sample to be tested (53).

2. The hybrid K-edge absorption-X-ray fluorescence analysis method according to claim 1, characterized in that: The second uranium / plutonium concentration ratio of the sample to be tested (53) is obtained according to the relationship between the K-series fluorescence peak areas of uranium and plutonium in the sample to be tested (53), specifically referring to: According to the K content of uranium in the sample (53) to be tested α2 Characteristic peaks and K of plutonium α1 The characteristic peak area relationship is used to obtain a second uranium / plutonium concentration ratio of the sample to be tested (53).

3. The hybrid K-edge absorption-X-ray fluorescence analysis method according to claim 1, characterized in that: The step of obtaining the first uranium / plutonium concentration ratio of the sample to be tested (53) according to the L-series fluorescence peak area relationship between uranium and plutonium in the sample to be tested (53) specifically refers to: According to the L of uranium in the sample (53) to be tested α Characteristic peaks and L of plutonium α The characteristic peak area relationship is used to obtain a first uranium / plutonium concentration ratio of the sample to be tested (53). The L α Characteristic peaks include L α1 Characteristic peaks and L α2 Characteristic peak, L α1 Characteristic peak area and L α2 The sum of the characteristic peak areas is L α Characteristic peak area.

4. The hybrid K-edge absorption-X-ray fluorescence analysis method according to claim 1, characterized in that: When obtaining the absorption spectrum of uranium in the sample to be tested (53) according to the X-rays after the uranium K boundary absorption of the sample to be tested (53), the following steps are also performed: Starting from when the X-rays reach the high voltage setting value and ending when the measurement time reaches the setting time, the primary spectrum of the X-ray energy that does not pass through the sample to be measured (53) within the time range is obtained as the blank spectrum of the X-rays.

5. A hybrid K-edge absorption-X-ray fluorescence analysis device, characterized in that: The invention comprises an X-ray emitting device (1), a K absorption detecting device (2), an L fluorescence detecting device (3) and an analyzing device, and also comprises a K fluorescence detecting device (8). The X-ray emitting device (1) is used to emit X-rays to irradiate the sample to be tested (53), so as to cause the sample to be tested (53) to produce uranium K edge absorption, and to stimulate the L series characteristic fluorescence of uranium and plutonium in the sample to be tested (53), and can also stimulate the K series characteristic fluorescence of uranium and plutonium in the sample to be tested (53). The K absorption detection device (2) is used to obtain the absorption spectrum of uranium in the sample to be tested (53) based on the X-rays absorbed by the uranium K boundary of the sample to be tested (53). The L fluorescence detection device (3) is used to obtain the L series fluorescence peak area relationship of uranium and plutonium in the sample (53) to be tested according to the L series characteristic fluorescence of uranium and plutonium in the sample (53) to be tested, The analysis device is electrically connected to the K absorption detection device (2) and the L fluorescence detection device (3) and is used to obtain the uranium concentration of the sample (53) to be tested according to the absorption spectrum of uranium in the sample (53) to be tested and the blank spectrum of X-rays, and to obtain the first uranium / plutonium concentration ratio of the sample (53) to be tested according to the relationship between the L series fluorescence peak areas of uranium and plutonium in the sample (53) to be tested, and to obtain the first plutonium concentration of the sample (53) to be tested according to the uranium concentration of the sample (53) to be tested and the first uranium / plutonium concentration ratio of the sample (53) to be tested; The K fluorescence detection device (8) is used to obtain the K series fluorescence peak area relationship of uranium and plutonium in the sample to be tested (53) according to the K series characteristic fluorescence of uranium and plutonium in the sample to be tested (53). The analysis device is also electrically connected to the K fluorescence detection device (8). The analysis device is used to obtain a second uranium / plutonium concentration ratio of the sample to be tested (53) based on the relationship between the K series fluorescence peak areas of uranium and plutonium in the sample to be tested (53), and to obtain a second plutonium concentration of the sample to be tested (53) based on the uranium concentration of the sample to be tested (53) and the second uranium / plutonium concentration ratio of the sample to be tested (53). When the first uranium / plutonium concentration ratio and / or the second uranium / plutonium concentration ratio is greater than a set ratio, the first plutonium concentration of the sample to be tested (53) is taken as the plutonium concentration value of the sample to be tested (53); When the first uranium / plutonium concentration ratio and / or the second uranium / plutonium concentration ratio is not greater than the set ratio, the first plutonium concentration / the second plutonium concentration of the sample to be tested (53) is taken as the plutonium concentration value of the sample to be tested (53).

6. The hybrid K-edge absorption-X-ray fluorescence analysis device according to claim 5, characterized in that: The X-ray emitting device (1) is directed toward the sample (53) to be tested. An acute angle is formed between the direction of the line connecting the receiving end of the K fluorescence detection device (8) and the sample to be tested (53) and the emission direction of the X-ray emission device (1).

7. The hybrid K-edge absorption-X-ray fluorescence analysis device according to claim 5 or 6, characterized in that: A collimator (11) is provided in front of the emitting end of the X-ray emitting device (1), and the X-rays emitted by the X-ray emitting device (1) and the connection line between the receiving end of the K fluorescence detection device (8) and the sample to be tested (53) all pass through the collimator (11). A collimator (7) is provided in the direction of the connection between the receiving end of the K fluorescence detection device (8) and the sample to be tested (53), and the collimator (7) is closer to the receiving end of the K fluorescence detection device (8) than the collimator sheet (11). The collimator (11) is provided with a first collimator hole at a position corresponding to the connection line between the receiving end of the K fluorescence detection device (8) and the sample to be tested (53), so as to converge the K series characteristic fluorescence of uranium and plutonium in the sample to be tested (53) and then pass through the collimator (7) and enter the K fluorescence detection device (8). The collimating plate (11) is provided with a second collimating hole at a position corresponding to the connection line between the X-ray emitting device (1) and the sample to be tested (53), and is used to converge the X-rays and irradiate the sample to be tested (53).

8. The hybrid K-edge absorption-X-ray fluorescence analysis device according to claim 5, characterized in that: It also includes a blank detection device (6), wherein the X-ray emitting device (1) is arranged on one side of the sample to be tested (53), and the blank detection device (6) and the K absorption detection device (2) are arranged on the other side of the sample to be tested (53). The connection line between the X-ray emitting device (1) and the receiving end of the K absorption detection device (2) passes through the sample to be tested (53), while the connection line between the X-ray emitting device (1) and the receiving end of the blank detection device (6) does not pass through the sample to be tested (53). The blank detection device (6) is used to obtain an original spectrum of X-ray energy based on X-rays that have not passed through the sample (53) to be tested, starting from when the X-rays reach a high voltage setting value and terminating when the measurement time reaches a setting time. The analysis device is also electrically connected to the blank detection device (6) and is used to use the original spectrum of X-ray energy as a blank spectrum of X-rays, thereby obtaining the uranium concentration of the sample (53) to be tested based on the absorption spectrum of uranium in the sample (53) to be tested and the blank spectrum of X-rays.

9. The hybrid K-edge absorption-X-ray fluorescence analysis device according to claim 8, characterized in that: A collimator (7) is provided in front of the receiving end of the blank detection device (6) and the receiving end of the K absorption detection device (2). The X-rays emitted by the X-ray emission device (1) pass through the collimator (7) and enter the receiving ends of the two devices. An adjustment plate (21) is also provided in front of the receiving end of the K absorption detection device (2) for adjusting the intensity of X-rays after absorption by the uranium K boundary of the sample to be tested (53). The adjustment plate (21) is closer to the sample to be tested (53) than the collimator (7) in front of the receiving end of the K absorption detection device (2).

10. The hybrid K-edge absorption-X-ray fluorescence analysis device according to claim 5, characterized in that: The X-ray emitting device (1) is directed toward the sample (53) to be tested. An acute angle is formed between the direction of the line connecting the receiving end of the L fluorescence detection device (3) and the sample to be tested (53) and the emission direction of the X-ray emission device (1).

11. The hybrid K-edge absorption-X-ray fluorescence analysis device according to claim 5 or 10, characterized in that: A diffraction crystal (31) is also provided in the direction of the connection between the receiving end of the L fluorescence detection device (3) and the sample to be tested (53). A baffle is provided inside the diffraction crystal (31), the baffle being perpendicular to the direction of the connecting line and used to block the radiation of the sample to be tested (53) and part of the X-rays scattered by the X-ray emitting device (1).

12. The hybrid K-edge absorption-X-ray fluorescence analysis device according to claim 5, characterized in that: The X-ray emitting device (1), the K absorption detection device (2) and the L fluorescence detection device (3) are all covered with a shielding body (9) for shielding the divergent X-rays and stray light. The shielding body (9) is made of a tungsten-nickel-iron alloy material, so that characteristic fluorescence of tungsten in the shielding body (9) is stimulated under X-ray irradiation, which is used for passive energy calibration and spectrum stabilization.

13. The hybrid K-edge absorption-X-ray fluorescence analysis device according to claim 5, characterized in that: It also includes a shielding cover (4) and a measuring chamber (5), The shielding cover (4) is arranged outside the X-ray emitting device (1), the K absorption detection device (2), the L fluorescence detection device (3) and the sample to be tested (53), and is used to shield the β and γ rays of the sample to be tested (53). The measuring chamber (5) is arranged in the shielding cover (4), and the cover is arranged outside the sample to be measured (53), so that the sample to be measured (53) is hermetically isolated from other devices. The measuring cavity (5) is provided with a sample transmission interface for communicating with an external chamber, so that the sample transmission system can transmit the sample (53) to be measured between the measuring cavity (5) and the chamber, and the shielding cover (4) is provided with an avoidance opening at the position of the sample transmission interface corresponding to the measuring cavity (5).

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