X-ray analysis device, control method therefor, and program

Abstract

Provided is a technology for appropriately removing sum peaks in the analysis results of an X-ray analysis device. A control method for an X-ray analysis device comprises: a step (S200) for acquiring numerical values related to characteristics of the X-ray analysis device; and a step (S202) for calculating, on the basis of the numerical values related to the characteristics, a gain adjustment value of a determination waveform caused by X-rays of a sample detected in the X-ray analysis device. The determination waveform is derived for pile-up determination, and in the pile-up determination, the gain of the determination waveform is adjusted on the basis of the adjustment value.

Description

X-ray analysis apparatus, its control method, and program

[0001] The present invention relates to an X-ray analysis apparatus, and more particularly to pile-up determination for sum peak removal in an X-ray analysis apparatus.

[0002] The profile of the analysis results from an X-ray fluorescence analyzer contains not only a main peak (e.g., Kα ray) but also a sum peak. The intensity of the sum peak depends on the count rate and the time resolution of the detector. A method for deriving the ratio of the mth sum peak intensity I(m+1) to the main peak intensity I(1) using the count rate and peaking time is disclosed in Non-Patent Document 1 (Ryohei Tanaka, Koretaka Yuge, Jun Kawai, Hussain Alawadhi, Artificial peaks in energy dispersive X-ray spectra: sum peaks, escape peaks, and diffraction peaks, X-RAY SPECTROMETRY, John Wiley & Sons, Ltd., 2017, 46, pp. 5-11).

[0003] Ryohei Tanaka, Koretaka Yuge, Jun Kawai, Hussain Alawadhi, Artificial peaks in energy dispersive X-ray spectra: sum peaks, escape peaks, and diffraction peaks, X-RAY SPECTROMETRY, John Wiley & Sons, Ltd., 2017, 46, p5-p11

[0004] When sum peaks are removed from the profile of analytical results using a conventional method such as that disclosed in Non-Patent Document 1, there are cases where the removal of sum peaks is insufficient.

[0005] The present invention has been devised in view of the above circumstances, and its purpose is to provide a technique for appropriately removing sum peaks in the analysis results of an X-ray analysis apparatus.

[0006] An X-ray analysis apparatus according to one aspect of the present disclosure includes an X-ray detector that detects X-rays from a sample, a differential wave conversion unit that converts a step wave caused by the X-rays detected by the X-ray detector into a differential wave, a first conversion unit that converts the differential wave into a trapezoidal wave, a second conversion unit that converts the differential wave into a waveform for determination with a peaking time shorter than that of the first conversion unit, and a pile-up determination unit that performs pile-up determination on the waveform for determination, wherein the pile-up determination unit adjusts the gain in the second conversion unit based on numerical values ​​related to the characteristics of the X-ray analysis apparatus.

[0007] An X-ray analysis apparatus according to another aspect of the present disclosure includes an X-ray detector that detects X-rays from a sample, a differential wave conversion unit that converts a step wave caused by the X-rays detected by the X-ray detector into a differential wave, a first conversion unit that converts the differential wave into a trapezoidal wave, a second conversion unit that converts the differential wave into a waveform for determination with a peaking time shorter than that of the first conversion unit, and a pile-up determination unit that performs pile-up determination on the waveform for determination, wherein the pile-up determination unit adjusts one or more thresholds used for pile-up determination based on numerical values ​​related to the characteristics of the X-ray analysis apparatus.

[0008] A control method for an X-ray analysis apparatus according to one aspect of the present disclosure includes the steps of acquiring numerical values ​​related to characteristics of the X-ray analysis apparatus, and calculating, based on the numerical values ​​related to the characteristics, an adjustment value for the gain of a determination waveform resulting from X-rays of a sample detected in the X-ray analysis apparatus, wherein the determination waveform is derived for pile-up determination, and in the pile-up determination, the gain of the determination waveform is adjusted based on the adjustment value.

[0009] A control method for an X-ray analysis apparatus according to another aspect of the present disclosure includes the steps of acquiring numerical values ​​related to characteristics of the X-ray analysis apparatus, and calculating, based on the numerical values ​​related to the characteristics, adjustment values ​​for one or more thresholds for pile-up determination in the X-ray analysis apparatus, wherein, in the pile-up determination, one or more thresholds are adjusted by the adjustment values ​​for a determination waveform caused by X-rays of a sample detected in the X-ray analysis apparatus.

[0010] A program according to an aspect of the present disclosure causes the computer to perform the above-described method for controlling an X-ray analysis apparatus when executed by one or more processors of the computer.

[0011] According to one aspect of the present disclosure, a technique is provided for appropriately removing sum peaks in analysis results from an X-ray analysis apparatus.

[0012] 6 is a schematic configuration diagram of an X-ray analysis apparatus 1 according to an embodiment of the present disclosure. FIG. 6 is a diagram for explaining an example of processing content of an output waveform from a first conversion filter 46. FIG. 6 is a diagram for explaining content of width determination. FIG. 6 is a diagram for explaining content of interval determination. FIG. 7 is a diagram showing a specific example of a waveform on which pile-up determination cannot be performed normally. FIG. 7 is a flowchart of processing performed for analyzing a sample in the X-ray analysis apparatus 1. FIG. 7 is a flowchart of a subroutine of step S20 of FIG. 6. FIG. 7 is a diagram for explaining an example of adjustment of a threshold. FIG. 7 is a flowchart of a modified example of the processing of FIG. 6. FIG. 7 is a flowchart of a subroutine of step S22.

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0014] [Configuration of X-ray Analysis Apparatus] Fig. 1 is a schematic diagram of an X-ray analysis apparatus 1 according to an embodiment of the present disclosure. In one implementation, the X-ray analysis apparatus 1 is an energy dispersive X-ray fluorescence analysis apparatus. As shown in Fig. 1, the X-ray analysis apparatus 1 includes an X-ray tube 10, an X-ray detector 12, a preamplifier 14, a differentiation circuit 16, an amplifier 18, an ADC (Analog to Digital Converter) 20, a CPU (Central Processing Unit) 30, a memory 31, and a signal processing device 40. The X-ray detector 12 is an energy dispersive spectrometer. The signal processing device 40 is a signal processing device for X-ray analysis.

[0015] The X-ray tube 10 emits primary X-rays to the sample S. The X-ray tube 10 has, for example, a target serving as an anode, a filament serving as a cathode, and a housing that houses the target and the filament. When a high voltage is applied to the target and a low voltage is applied to the filament, thermoelectrons emitted from the filament collide with the end face of the target, generating primary X-rays at the end face. The primary X-rays generated at the end face of the target are emitted to the sample S. When the sample S is irradiated with the primary X-rays, fluorescent X-rays excited by the primary X-rays are emitted from the sample S and enter the X-ray detector 12.

[0016] The X-ray detector 12 detects the intensity of fluorescent X-rays in a predetermined wavelength range. The X-ray detector 12 is disposed inside a housing and has a detection element that detects the intensity of fluorescent X-rays in the wavelength range. The detection element is, for example, a lithium drift type Si semiconductor element.

[0017] The output signal from the X-ray detector 12 is amplified by a preamplifier 14. The preamplifier 14 converts the output signal into a staircase-like signal. Each step of the staircase-like signal indicates the detection of fluorescent X-rays. The height of each step represents the wavelength λ, i.e., the X-ray energy E.

[0018] The output signal amplified by the preamplifier 14 is sent to a differentiating circuit 16. The differentiating circuit 16 is composed of a capacitor C and a resistor R, and converts the staircase wave into a differential wave expressed by the following equation (1). By converting the staircase wave into a differential wave, a wide dynamic range can be achieved, resulting in high resolution. The differential wave is amplified by an amplifier 18 and sent to an ADC 20.

[0019]

[0020] where τ (=RC) is a time constant, T is a sampling period, n is the number of samples, and a is (exp(−T / τ)).

[0021] The ADC 20 samples the differential wave, which is an analog signal, at a predetermined sampling period and converts it into a digital signal (hereinafter referred to as a differential wave digital signal). The differential wave digital signal is input to the signal processing device 40.

[0022] The signal processing device 40 is generally configured by a logic device such as an FPGA (Field-Programmable Gate Array).

[0023] In this embodiment, the signal processing device 40 includes an offset correction unit 44, a first conversion filter 46, a second conversion filter 47, a baseline correction unit 48, a pile-up determination processing unit 49, a gain / offset adjustment unit 50, a peak detector 52, and a histogram memory 54. In the signal processing device 40, the offset correction unit 44, the first conversion filter 46, the second conversion filter 47, the baseline correction unit 48, the pile-up determination processing unit 49, the gain / offset adjustment unit 50, the peak detector 52, and the histogram memory 54 may each be realized as an independent hardware resource, or two or more of them may be realized as a common hardware resource.

[0024] The offset correction unit 44 performs offset correction on the differential wave digital signal provided by the ADC 20 and outputs the corrected differential wave digital signal to the first conversion filter 46 and the second conversion filter 47 .

[0025] Each of the first conversion filter 46 and the second conversion filter 47 is a digital filter configured to convert the differential wave corrected by the offset correction unit 44 into a trapezoidal wave expressed by equation (2).

[0026]

[0027] Here, in equation (2), M corresponds to the time of the upper base of the trapezoidal wave, and N represents the rise time and fall time of the trapezoidal wave. M is also referred to as flat time, and N is also referred to as peaking time. The first conversion filter 46 is a so-called slow filter, and the second conversion filter 47 is a so-called fast filter. More specifically, the values ​​of M and N of the second conversion filter 47 are smaller than the values ​​of M and N of the first conversion filter 46.

[0028] The pile-up determination processor 49 uses the waveform converted by the second conversion filter 47 as a "determination waveform" for pile-up determination.

[0029] The output waveform from the first conversion filter 46 is input to a peak detector 52 after the baseline and gain are adjusted by a baseline correction section 48 and a gain / offset adjustment section 50 .

[0030] The peak detector 52 detects peaks in the output waveform and obtains the wave height value (peak top value) of each peak. The pile-up determination processor 49 determines the occurrence of a pile-up as a result of the pile-up determination and outputs information about the sum peak due to the pile-up to the peak detector 52. The peak detector 52 removes peaks in the output waveform that have been identified as sum peaks by the pile-up determination processor 49 from the targets for obtaining the peak top value. The peak detector 52 increments the count value of the X-ray energy E corresponding to the peak top value for each peak and stores it in the histogram memory 54.

[0031] The memory 31 includes a program storage area 31A that non-temporarily stores program data and a data storage area 31B that stores data. The X-ray analysis apparatus 1 performs various processes by the CPU 30 executing programs stored in the program storage area 31A (or a storage device outside the X-ray analysis apparatus 1).

[0032] The CPU 30 generates a pulse-height distribution diagram (energy spectrum histogram) based on the count values ​​stored in the histogram memory 54. The pulse-height distribution diagram shows the fluorescent X-ray energy E on the horizontal axis and the element content (intensity) on the vertical axis. In the pulse-height distribution diagram, peaks specific to each element appear at positions corresponding to the energy E of the fluorescent X-rays emitted from the elements contained in the sample S. The CPU 30 performs qualitative and quantitative analysis of the contained elements based on the positions of these peaks and their X-ray intensity values.

[0033] 2 is a diagram for explaining an example of the processing of the output waveform from the first conversion filter 46. In FIG. 2, the vertical axis represents amplitude, and the horizontal axis represents time.

[0034] The graph shown in Fig. 2 shows waveforms WF01, WF02, and WF03 for X-rays obtained from a certain sample. The waveform WF01 is the waveform output from the preamplifier 14. The waveform WF02 is the waveform output from the second conversion filter 47. The waveform WF03 is the waveform output from the first conversion filter 46. In Fig. 2, the amplitudes of the waveforms WF01, WF02, and WF03 are appropriately offset in order to present these waveforms on a single graph for easy viewing.

[0035] The waveform WF01 includes five steps. In Fig. 2, the five steps are numbered "1" to "5." The waveforms WF02 and WF03 each have numbers "1" to "5" added to the portions corresponding to the five steps of the waveform WF01.

[0036] In one implementation example, in pile-up determination using waveform WF02, it is determined that a pile-up has occurred at the peaks marked with the numbers "2" and "3" because they are too close to each other. As a result, of the peaks in waveform WF03, the peaks marked with the numbers "2" and "3" are excluded from the peak detector 52 from obtaining peak top values. Pile-up determination based on the distance between two adjacent peaks will be described later as "distance determination."

[0037] Furthermore, in pile-up determination using waveform WF02, the peak marked with the number "4" and the peak marked with the number "5" are treated as a single peak. Then, because the width of this single peak is too wide, it is determined that a pile-up has occurred at the peak marked with the number "4" and the peak marked with the number "5." As a result, of the peaks in waveform WF03, the peak marked with the number "4" and the peak marked with the number "5" are excluded from the peak detector 52 from obtaining peak top values. Pile-up determination based on peak width will be described later as "width determination."

[0038] [Pile-up Determination] Two types of determination methods (width determination and interval determination) will be described below as specific examples of pile-up determination by the pile-up determination processor 49. The pile-up determination processor 49 performs at least one of the following two types of determination methods.

[0039] <Width Determination> Fig. 3 is a diagram for explaining the contents of the width determination. The width determination is also called a width test. The width determination determines whether a pileup has occurred based on whether the peak width of each peak in the waveform exceeds a given threshold.

[0040] 3 shows a waveform WF11. The waveform WF11 is output from the second conversion filter 47. In the graph including the waveform WF11, the vertical axis represents amplitude and the horizontal axis represents time.

[0041] The width determination uses a first width determination threshold TH11 and a second width determination threshold TH12. More specifically, peaks are identified in the waveform WF11 at portions exceeding the first width determination threshold TH11. The peak width of each peak is then calculated, and the calculated peak width is compared with the second width determination threshold TH12.

[0042] The signal SG11 represents the output signal of a circuit (a component of the pile-up determination processing unit 49) that changes the output value depending on whether the amplitude of the waveform WF11 exceeds a given value (a value that is a specific percentage of the peak amplitude).

[0043] In the example of FIG. 3 , a peak width WD11 is calculated for peak PK11. A peak width WD12 is calculated for peaks PK12 and PK13. The peak width WD11 is smaller than the second threshold value TH12 for width determination. Therefore, it is determined that a pileup has not occurred in peak PK11. On the other hand, the peak width WD12 is larger than the second threshold value TH12 for width determination. Therefore, it is determined that a pileup has occurred in peaks PK12 and PK13.

[0044] <Interval Determination> Fig. 4 is a diagram for explaining the details of the interval determination. The interval determination is also called an isolation test. The interval determination determines whether a pileup has occurred based on whether the interval between adjacent peaks is closer than a given threshold.

[0045] A waveform WF21 is shown in Fig. 4. The waveform WF21 is output from the second conversion filter 47. In Fig. 4, the vertical axis represents amplitude, and the horizontal axis represents time.

[0046] The interval determination uses a first interval determination threshold TH21 and a second interval determination threshold TH22. More specifically, peaks are identified in the waveform WF21 for portions exceeding the first interval determination threshold TH21. The first interval determination threshold TH21 may be the same value as the first width determination threshold TH11. The interval between two adjacent peaks is then calculated, and the calculated peak interval is compared with the second interval determination threshold TH22.

[0047] In the example of Figure 4, four peaks PK21, PK22, PK23, and PK24 are identified in waveform WF21. The value of the interval SP21 between peaks PK21 and PK22 is greater than the second threshold value TH22 for interval determination. Therefore, it is determined that a pileup has not occurred between peaks PK21 and PK22. On the other hand, the value of the interval SP22 between peaks PK23 and PK24 is smaller than the second threshold value TH22 for interval determination. Therefore, it is determined that a pileup has occurred between peaks PK23 and PK24.

[0048] [Specific Example of Waveform for which Pile-up Detection Cannot Be Normalized] Fig. 5 is a diagram showing a specific example of a waveform for which pile-up detection cannot be normalized. Fig. 5 shows a waveform WF31 as an example of a waveform output from the second conversion filter 47. In Fig. 5, the vertical axis represents amplitude, and the horizontal axis represents time.

[0049] In the X-ray analysis apparatus 1, for example, individual differences in the X-ray detectors 12 installed can cause differences in the waveform output from the second conversion filter 47 for each individual X-ray analysis apparatus 1. For example, even when X-rays are detected from the same sample, the waveform output from the second conversion filter 47 of one X-ray analysis apparatus 1 may have a portion exceeding the first threshold value TH11 for width determination, as shown as waveform WF11 in FIG. 3, while another X-ray analysis apparatus 1 may not have a portion exceeding the first threshold value TH11 for width determination, as shown as waveform WF31 in FIG. 5. If the waveform does not have a portion exceeding the first threshold value TH11 for width determination, a peak to be subjected to pile-up determination will not be identified in the waveform. As a result, it is conceivable that appropriate pile-up determination will not be performed, and the peak detector 52 will not sufficiently remove sum peaks from the output waveform of the first conversion filter 46.

[0050] [Gain Adjustment] In the X-ray analysis apparatus 1, the pile-up determination processing unit 49 appropriately performs pile-up determination and performs gain adjustment of the waveform output from the second conversion filter 47 in order to sufficiently remove sum peaks from the output waveform of the first conversion filter 46.

[0051] More specifically, the gain adjustment value is determined based on the individual differences of the X-ray analysis apparatus 1. Then, the pile-up determination processing unit 49 treats the product of the original amplitude and the gain adjustment value as the amplitude after gain adjustment for the entire waveform output from the second conversion filter 47.

[0052] It is assumed that the X-ray analysis apparatus 1 that outputs the waveform WF31 in Fig. 5 has a characteristic that derives a lower amplitude overall than the X-ray analysis apparatus 1 that outputs the waveform WF11 in Fig. 3. The pile-up determination processing unit 49 of the X-ray analysis apparatus 1 that has such a characteristic (individual difference) treats the product of the amplitude of the waveform WF31 in Fig. 5 and the gain adjustment value as the amplitude after gain adjustment. As a result, the amplitude of the waveform WF31 in Fig. 5 is increased overall so that it approaches the amplitude of the waveform WF11 in Fig. 3.

[0053] In one implementation example, the gain adjustment value is determined based on the analysis results of a standard sample in each X-ray analysis device 1. An example of the standard sample is an alloy of tin and aluminum. More specifically, X-ray analysis is performed on the standard sample in each X-ray analysis device 1. Then, the energy position A of the tin Kα ray in the analysis results is determined. In this sense, tin constitutes an example of a "standard substance." A reference value X for the energy position of the tin Kα ray is stored in the data storage area 31B of each X-ray analysis device 1. The CPU 30 calculates "X / A" as the gain adjustment value. The pile-up determination processing unit 49 performs pile-up determination using the calculated gain adjustment value.

[0054] The gain adjustment value described above increases as the value of the energy position specified for the reference material decreases. Thus, in gain adjustment using the gain adjustment value, the smaller the value of the energy position specified for the reference material, the higher the magnification for enhancing the waveform output from the second conversion filter 47 in pile-up determination.

[0055] [Processing Flow] Fig. 6 is a flowchart of processing performed for analyzing a sample in the X-ray analysis apparatus 1. The processing in Fig. 6 is performed, for example, by the CPU 30 executing a given program. The processing in Fig. 6 is started when the X-ray analysis apparatus 1 is powered on (after initial settings are completed).

[0056] In step S10, the X-ray analysis apparatus 1 determines whether or not an instruction to set a gain adjustment value has been received. In one implementation example, the X-ray analysis apparatus 1 includes an input device such as a keyboard or buttons, and an instruction to set a gain adjustment value is input to the X-ray analysis apparatus 1 by operating the input device. If the X-ray analysis apparatus 1 determines that an instruction to set a gain adjustment value has been received (YES in step S10), the control proceeds to step S20; if not (NO in step S10), the control proceeds to step S30.

[0057] In step S20, the X-ray analysis apparatus 1 sets a gain adjustment value. The details of step S20 will be described later with reference to FIG.

[0058] In step S30, the X-ray analysis apparatus 1 determines whether or not a sample analysis has been instructed. In one implementation example, the X-ray analysis apparatus 1 includes an input device such as a keyboard or buttons, and the instruction for sample analysis is input to the X-ray analysis apparatus 1 by operating the input device. If the X-ray analysis apparatus 1 determines that a sample analysis has been instructed (YES in step S30), the control proceeds to step S40; otherwise (NO in step S30), the control returns to step S10.

[0059] In step S40, the X-ray analysis apparatus 1 performs X-ray analysis of the sample. At this time, if a gain adjustment value is stored in the data storage area 31B, the pile-up determination processing unit 49 uses the gain adjustment value to adjust the gain of the waveform output from the second conversion filter 47 as described above. Thereafter, the X-ray analysis apparatus 1 returns control to step S10.

[0060] Fig. 7 is a flowchart of a subroutine of step S20 in Fig. 6. In step S200, the X-ray analysis apparatus 1 acquires the results of X-ray analysis of the standard material in the X-ray analysis apparatus 1. At this time, the X-ray analysis of the standard material may be performed in the X-ray analysis apparatus 1.

[0061] In step S202, the X-ray analysis apparatus 1 calculates a gain adjustment value using the analysis result acquired in step S200. An example of the calculation of the gain adjustment value is the calculation of "X / A" described above.

[0062] In step S204, the X-ray analysis apparatus 1 stores the gain adjustment value calculated in step S202 in the data storage area 31B, and returns the control to FIG.

[0063] In the present embodiment described above, the gain of the waveform for pile-up determination (the waveform output from the second conversion filter 47) is adjusted based on individual differences in the X-ray analysis apparatus 1. A signal with a slow rise time may be generated due to differences in the incident position of X-rays on the X-ray detector 12, etc. Even in such cases, the amplitude of the waveform for pile-up determination is appropriately increased, thereby more reliably detecting sum peaks. Furthermore, sum peaks due to elements that generate fluorescent X-rays with low energy and sum peaks due to X-rays that are scattered by a sample or the like and are incident on the X-ray detector 12 are more reliably detected.

[0064] [Adjustment of Threshold Value] In the X-ray analysis apparatus 1, instead of adjusting the gain of the waveform output from the second conversion filter 47 in pile-up determination, the threshold value used may be changed.

[0065] Due to individual differences in the X-ray analysis device 1, for the same sample as waveform WF11 in Figure 3, a waveform may be created that does not have any portion that exceeds the first threshold value TH11 for width determination, as shown as waveform WF31 in Figure 5.

[0066] In such a case, the X-ray analysis apparatus 1 adjusts the threshold value for peak determination (first threshold value TH11 for width determination) instead of adjusting the gain of the waveform, thereby properly detecting the peaks contained in the waveform and properly performing pile-up determination.

[0067] Fig. 8 is a diagram illustrating an example of threshold adjustment. The waveform WF31 shown in Fig. 8 is the same as the waveform WF shown in Fig. 5. In the example of Fig. 8, the value of the first threshold TH11 for width determination has been changed to a value indicated as threshold TH19. As a result, the waveform WF31 now has a portion exceeding threshold TH19, and peaks in the waveform WF31 can be properly detected.

[0068] Such threshold adjustment is also performed on the first threshold TH21 for determining the gap.

[0069] In order to adjust the threshold as described above, a threshold adjustment value is calculated in the X-ray analysis apparatus 1. An example of the threshold adjustment value is expressed as "A / X" using an energy position A identified based on the analysis results of the above-described standard material and a reference value X.

[0070] The pile-up determination processor 49 adjusts the thresholds by multiplying each of the first threshold value TH11 for width determination and the first threshold value TH21 for spacing determination by the threshold adjustment value. That is, the adjusted thresholds are expressed as the product of the first threshold value TH11 for width determination and "A / X" and the product of the first threshold value TH21 for spacing determination and "A / X".

[0071] Fig. 9 is a flowchart of a modified example of the process of Fig. 6. In the process of Fig. 9, a threshold adjustment value is set instead of the gain adjustment value set in the process of Fig. 6. More specifically, the process of Fig. 9 includes steps S12 and S22 instead of steps S10 and S20 of Fig. 6.

[0072] In step S12, the X-ray analysis apparatus 1 determines whether or not an instruction to set a threshold adjustment value has been received. If the X-ray analysis apparatus 1 determines that an instruction to set a threshold adjustment value has been received (YES in step S12), the control proceeds to step S22. If not (NO in step S12), the control proceeds to step S30.

[0073] In step S22, the X-ray analysis apparatus 1 sets the threshold adjustment value. Fig. 10 is a flowchart of the subroutine of step S22.

[0074] In step S220, the X-ray analysis apparatus 1 acquires the results of the X-ray analysis of the standard material in the X-ray analysis apparatus 1. At this time, the X-ray analysis of the standard material may be performed in the X-ray analysis apparatus 1.

[0075] In step S222, the X-ray analysis apparatus 1 calculates a threshold adjustment value using the analysis result acquired in step S200. An example of the calculation of the threshold adjustment value is the calculation of "A / X" described above.

[0076] In step S224, the X-ray analysis apparatus 1 stores the threshold adjustment value calculated in step S202 in the data storage area 31B, and returns the control to FIG.

[0077] 9 and 10, adjustment values ​​are calculated to adjust the first threshold value TH11 for width determination and the first threshold value TH21 for gap determination, thereby changing the peak detection threshold value based on individual differences in the X-ray analysis apparatus 1, as described with reference to FIG.

[0078] The value of the threshold adjustment value explained above becomes smaller as the value of the energy position specified for the reference material becomes smaller. As a result, the adjusted threshold value using the threshold adjustment value becomes smaller as the value of the energy position specified for the reference material becomes smaller.

[0079] Aspects It will be understood by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0080] (Item 1) An X-ray analysis apparatus according to one aspect includes an X-ray detector that detects X-rays from a sample, a differential wave conversion unit that converts a step wave resulting from the X-rays detected by the X-ray detector into a differential wave, a first conversion unit that converts the differential wave into a trapezoidal wave, a second conversion unit that converts the differential wave into a waveform for determination with a peaking time shorter than that of the first conversion unit, and a pile-up determination unit that performs pile-up determination on the waveform for determination, wherein the pile-up determination unit may adjust a gain in the second conversion unit based on a numerical value related to a characteristic of the X-ray analysis apparatus.

[0081] According to the X-ray analysis device described in the first aspect, a technique for appropriately removing sum peaks in the analysis results of the X-ray analysis device is provided.

[0082] (Section 2) Another aspect of the X-ray analysis apparatus is an X-ray analysis apparatus comprising an X-ray detector that detects X-rays from a sample, a differential wave conversion unit that converts a step wave caused by the X-rays detected by the X-ray detector into a differential wave, a first conversion unit that converts the differential wave into a trapezoidal wave, a second conversion unit that converts the differential wave into a waveform for determination with a peaking time shorter than that of the first conversion unit, and a pile-up determination unit that performs pile-up determination on the waveform for determination, wherein the pile-up determination unit may adjust one or more thresholds used for the pile-up determination based on numerical values ​​related to the characteristics of the X-ray analysis apparatus.

[0083] According to the X-ray analysis device described in the second aspect, a technique for appropriately removing sum peaks in the analysis results of the X-ray analysis device is provided.

[0084] (Clause 3) In the X-ray analysis apparatus described in clause 1 or 2, the pile-up determination may include at least one of a determination based on the width of a peak in the determination waveform and a determination based on the interval between peaks in the determination waveform.

[0085] According to the X-ray analysis device described in the third aspect, pile-up determination is performed from multiple angles, and as a result, sum peaks can be more appropriately removed from the analysis results of the X-ray analysis device.

[0086] (4) In the X-ray analysis device according to any one of the first to third aspects, the numerical value relating to the characteristic may be based on the energy position of a standard substance in an analysis of a standard sample by the X-ray analysis device.

[0087] According to the X-ray analysis apparatus described in paragraph 4, the gain or threshold is appropriately adjusted. (5) In the X-ray analysis apparatus described in paragraph 4, the standard sample may be an alloy containing tin and aluminum, and the standard substance may be tin.

[0088] According to the X-ray analysis apparatus described in the fifth aspect, the gain or threshold can be appropriately adjusted by using a standard sample that is relatively easy to obtain.

[0089] (Clause 6) A control method for an X-ray analysis apparatus according to one aspect is a control method for an X-ray analysis apparatus, comprising the steps of: acquiring a numerical value relating to a characteristic of the X-ray analysis apparatus; and calculating, based on the numerical value relating to the characteristic, an adjustment value for the gain of a determination waveform resulting from X-rays of a sample detected by the X-ray analysis apparatus, wherein the determination waveform is derived for pile-up determination, and during the pile-up determination, the gain of the determination waveform is adjusted based on the adjustment value.

[0090] According to the control method of the X-ray analysis apparatus described in Section 6, a technique for appropriately removing sum peaks in the analysis results of the X-ray analysis apparatus is provided.

[0091] (Clause 7) Another aspect of the control method for an X-ray analysis apparatus is a control method for an X-ray analysis apparatus, comprising the steps of: acquiring numerical values ​​related to characteristics of the X-ray analysis apparatus; and calculating, based on the numerical values ​​related to the characteristics, adjustment values ​​for one or more thresholds for pile-up determination in the X-ray analysis apparatus, wherein, in the pile-up determination, the one or more thresholds may be adjusted by the adjustment values ​​for a determination waveform resulting from X-rays of a sample detected in the X-ray analysis apparatus.

[0092] According to the control method of the X-ray analysis apparatus described in item 7, a technique for appropriately removing sum peaks in the analysis results of the X-ray analysis apparatus is provided.

[0093] (Item 8) In the method for controlling an X-ray analysis apparatus described in Item 7 or 8, the pile-up judgment may include at least one of a judgment based on the width of a peak in the judgment waveform and a judgment based on the interval between peaks in the judgment waveform.

[0094] According to the control method of the X-ray analysis apparatus described in Section 8, pile-up determination is performed from multiple angles, and as a result, sum peaks can be more appropriately removed from the analysis results of the X-ray analysis apparatus.

[0095] (Item 9) In the method for controlling an X-ray analysis apparatus described in any one of Items 7 to 9, the numerical value relating to the characteristic may be based on the energy position of a standard substance in an analysis of a standard sample by the X-ray analysis apparatus.

[0096] According to the control method for an X-ray analysis apparatus described in Item 9, the gain or threshold is adjusted appropriately.

[0097] (Item 10) In the method for controlling an X-ray analysis apparatus according to item 9, the standard sample may be an alloy containing tin and aluminum, and the standard substance may be tin.

[0098] According to the control method for an X-ray analysis apparatus described in item 10, the gain or threshold is appropriately adjusted using a standard sample that is relatively easy to obtain.

[0099] (Item 11) A program according to one aspect may be executed by one or more processors of a computer to cause the computer to implement the method for controlling an X-ray analysis apparatus according to any one of items 6 to 10.

[0100] The program described in paragraph 11 provides a technique for appropriately removing sum peaks in the analysis results of an X-ray analysis apparatus.

[0101] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above-described embodiments, and is intended to include all modifications within the meaning and scope of the claims. Furthermore, it is intended that each technique in the embodiments can be implemented alone or, if necessary, in combination with other techniques in the embodiments to the extent possible.

[0102] 1 X-ray analysis device, 10 X-ray tube, 12 X-ray detector, 14 preamplifier, 16 differentiating circuit, 18 amplifier, 20 ADC.

Claims

1. an X-ray detector for detecting X-rays from the sample; a differential wave conversion unit that converts a step wave caused by the X-rays detected by the X-ray detector into a differential wave; a first conversion unit for converting the differential wave into a trapezoidal wave; a second conversion unit that converts the differential wave into a waveform for determination with a peaking time shorter than that of the first conversion unit; a pile-up determination unit for performing pile-up determination on the determination waveform, the pile-up determination unit adjusts a gain in the second conversion unit based on a value related to a characteristic of the X-ray analysis apparatus; An X-ray analysis apparatus, wherein the numerical values ​​relating to the characteristics are based on the energy position of a standard substance in an analysis of a standard sample by the X-ray analysis apparatus.

2. an X-ray detector for detecting X-rays from the sample; a differential wave conversion unit that converts a step wave caused by the X-rays detected by the X-ray detector into a differential wave; a first conversion unit for converting the differential wave into a trapezoidal wave; a second conversion unit that converts the differential wave into a waveform for determination with a peaking time shorter than that of the first conversion unit; a pile-up determination unit for performing pile-up determination on the determination waveform, the pile-up determination unit adjusts one or more thresholds used for the pile-up determination based on a numerical value related to a characteristic of the X-ray analysis device; An X-ray analysis apparatus, wherein the numerical values ​​relating to the characteristics are based on the energy position of a standard substance in an analysis of a standard sample by the X-ray analysis apparatus.

3. 3. The X-ray analysis apparatus according to claim 1, wherein the pile-up determination includes at least one of a determination based on a width of a peak in the determination waveform and a determination based on an interval between peaks in the determination waveform.

4. the standard sample is an alloy containing tin and aluminum, 3. The X-ray analysis apparatus according to claim 1, wherein the standard substance is tin.

5. A control method for an X-ray analysis apparatus, comprising: obtaining a value related to a characteristic of the X-ray analysis device; and calculating an adjustment value for the gain of a determination waveform caused by X-rays of a sample detected by the X-ray analysis device based on the numerical value related to the characteristic, the waveform for determination is derived for pile-up determination, In the pile-up determination, a gain of the determination waveform is adjusted based on the adjustment value; A method for controlling an X-ray analysis apparatus, wherein the numerical value relating to the characteristic is based on the energy position of a standard material in an analysis of the standard sample by the X-ray analysis apparatus.

6. A control method for an X-ray analysis apparatus, comprising: obtaining a value related to a characteristic of the X-ray analysis device; and calculating an adjustment value for one or more threshold values ​​for pile-up determination in the X-ray analysis device based on the numerical value related to the characteristic, In the pile-up determination, the one or more thresholds are adjusted by the adjustment value for a determination waveform caused by X-rays of a sample detected by the X-ray analysis device; A method for controlling an X-ray analysis apparatus, wherein the numerical value relating to the characteristic is based on the energy position of a standard material in an analysis of the standard sample by the X-ray analysis apparatus.

7. 7. The method for controlling an X-ray analysis apparatus according to claim 5, wherein the pile-up determination includes at least one of a determination based on a width of a peak in the determination waveform and a determination based on an interval between peaks in the determination waveform.

8. the standard sample is an alloy containing tin and aluminum, 7. The method for controlling an X-ray analysis apparatus according to claim 5, wherein the standard substance is tin.

9. A program that, when executed by one or more processors of a computer, causes the computer to implement the method for controlling an X-ray analysis apparatus according to claim 5 or 6.