JP2020024176A - Electron probe microanalyzer, data processing method and data processing program - Google Patents

Abstract

To provide an electron probe microanalyzer, a data processing method and a data processing program each of which enables work for correcting data of a standard sensitivity curve to be simplified.SOLUTION: A memory part 20 memorizes data of a standard sensitivity curve, a standard sensitivity value, and initial data of the standard sensitivity curve every acceleration voltage of an electron beam. An update processing part 13 updates the standard sensitivity value memorized in the memory part 20 based on an actual value of the standard sensitivity value by one acceleration voltage, and then, updates the standard sensitivity value memorized in the memory part 20 by using a standard sensitivity curve calculation processing part 12. Also, the update processing part obtains a ratio of change of the standard sensitivity value from the initial data of data of each standard sensitivity curve memorized in the memory part 20 when the accelerating voltage is changed, calculates the standard sensitivity value in the other acceleration voltage from the ratio and the actual value of the standard sensitivity value, and updates the data of the standard sensitivity curve based on the standard sensitivity value and causes the memory part 20 to memorize the updated data.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electron beam microanalyzer for detecting X-rays generated by irradiating a sample with an electron beam using a wavelength dispersive X-ray spectrometer, and to a data processing method and a data processing program used for the same. .

  An electron probe microanalyzer (EPMA: Electron Probe Microanalyzer) is provided with a wavelength dispersive X-ray spectrometer (WDS) as an X-ray spectrometer, and the X-ray spectrometer uses the X-ray spectrometer. The spectral data can be obtained by detecting (see, for example, Patent Documents 1 to 4 below). In the qualitative analysis using EPMA, the type of element contained in the sample is specified based on the peak wavelength of the spectrum data, and the height (X-ray intensity) of each peak is compared with the standard sensitivity, whereby each element is analyzed. Can be determined.

  Since the sensitivity of the X-ray spectrometer differs from device to device, data of a standard sensitivity curve representing the relationship between the standard sensitivity value and the wavelength is stored in each device, and the data of the standard sensitivity curve is corrected as necessary. It is common. Here, the standard sensitivity value is a count rate of an X-ray signal per unit beam current amount measured when each element has a concentration of 100%. Since the standard sensitivity value changes depending on the X-ray generation efficiency and the detection efficiency according to the wavelength of the X-ray spectrometer, the data of the standard sensitivity curve includes a series (X-rays) corresponding to the energy rank related to X-ray generation. (K line, L line, M line) are stored in the storage unit. By using the data of the standard sensitivity curve, the element concentration of the sample can be calculated.

  FIG. 5 is a diagram showing an example of the standard sensitivity curve. As shown in FIG. 5, when the relationship between the standard sensitivity value and the wavelength is approximated by a polynomial using the least squares method or the like, a standard sensitivity curve that changes smoothly is obtained. Since the standard sensitivity curve differs depending on the acceleration voltage of the electron beam (irradiated electron beam) irradiating the sample, the standard sensitivity curve is calculated under a plurality of different acceleration voltage conditions, and the standard sensitivity value at the acceleration voltage between them is linearly calculated A method of finding by interpolation has been put to practical use.

JP 2007-285786 A JP 2008-122267 A JP 2010-107334 A JP 2011-227056 A

  The sensitivity of the EPMA X-ray spectrometer not only changes when the spectroscopic element or the X-ray detector is replaced with a new one, but may also deteriorate due to aging of these elements. Therefore, in order to obtain an accurate quantitative value by qualitative analysis, it is desirable to correct the data of the standard sensitivity curve at regular intervals.

  However, the number of standard sensitivity values that must be obtained to modify the data of the standard sensitivity curve is very large. More specifically, it is necessary to acquire about 30 standard sensitivity values in total for K-line, L-line, and M-line, each of which is only about 10 standard sensitivity values for only one spectral element. Yes, this operation needs to be performed for all the spectroscopic elements used in the apparatus. Furthermore, in order to calculate a standard sensitivity curve under a plurality of different acceleration voltage conditions, it is necessary to obtain a standard sensitivity value obtained by multiplying the number by the number. Therefore, it has been substantially difficult to periodically correct the data of the standard sensitivity curve for all acceleration voltage conditions.

  The present invention has been made in view of the above circumstances, and has as its object to provide an electron beam microanalyzer, a data processing method, and a data processing program that can simplify the work of correcting data of a standard sensitivity curve. I do.

(1) An electron beam microanalyzer according to the present invention includes an electron beam irradiation unit, a wavelength dispersive X-ray spectrometer, a standard sensitivity curve calculation processing unit, a storage unit, and an update processing unit. The electron beam irradiation unit irradiates a sample with an electron beam to generate X-rays. The wavelength dispersive X-ray spectrometer detects X-rays generated from a sample and acquires spectrum data. The standard sensitivity curve calculation processing unit calculates a standard sensitivity curve representing a relationship between a standard sensitivity value and a wavelength of the wavelength dispersive X-ray spectrometer. The storage unit stores the standard sensitivity curve data calculated by the standard sensitivity curve calculation processing unit, the standard sensitivity value for each wavelength used in the calculation of the standard sensitivity curve, and a value obtained using one representative device in advance. The initial data of the obtained standard sensitivity curve is stored for each electron beam acceleration voltage. The update processing unit updates the standard sensitivity value stored in the storage unit based on the measured value of the standard sensitivity value at one acceleration voltage, and uses the standard sensitivity curve calculation processing unit to update the storage unit. The data of the standard sensitivity curve stored in the storage unit is updated, and the rate at which the standard sensitivity value changes when the acceleration voltage changes is obtained from the initial data of each standard sensitivity curve stored in the storage unit. Then, a standard sensitivity value at another acceleration voltage is calculated from the measured value of the standard sensitivity value, and the data of the standard sensitivity curve is updated based on the standard sensitivity value and stored in the storage unit.

  According to such a configuration, the data of the standard sensitivity curve at another acceleration voltage can be updated collectively using the measured values of the standard sensitivity values acquired at one acceleration voltage. Therefore, for each acceleration voltage, it is not necessary to update the data of the standard sensitivity curve using the measured value of the standard sensitivity value, so that the work of correcting the data of the standard sensitivity curve can be simplified.

(2) The electron beam microanalyzer may further include an element concentration calculation processing unit. The element concentration calculation processing section calculates the element concentration of the sample using the data of the standard sensitivity curve updated by the update processing section.

  According to such a configuration, the element concentration of the sample can be calculated using the data of the standard sensitivity curve at each accelerating voltage updated collectively. Therefore, the element concentration of the sample can be easily calculated using the data of the standard sensitivity curve for each acceleration voltage obtained by the simplified operation.

(3) The data processing method according to the present invention includes an electron beam irradiation unit that irradiates a sample with an electron beam to generate X-rays, and a wavelength-dispersive X-ray that detects X-rays generated from the sample and acquires spectrum data. X-ray spectrometer, data of a standard sensitivity curve representing the relationship between the standard sensitivity value and the wavelength of the wavelength dispersive X-ray spectrometer, the standard sensitivity value for each wavelength used for calculating the standard sensitivity curve, and A storage unit for storing initial data of a standard sensitivity curve obtained by using one of the representative devices for each acceleration voltage of an electron beam. And an updating step. In the standard sensitivity curve calculation step, a standard sensitivity curve representing a relationship between a standard sensitivity value and a wavelength of the wavelength dispersive X-ray spectrometer is calculated. In the updating step, the standard sensitivity value stored in the storage unit is updated based on an actual measurement value of the standard sensitivity value at one acceleration voltage, and stored in the storage unit using the standard sensitivity curve calculation step. While updating the data of the standard sensitivity curve, the rate at which the standard sensitivity value changes when the acceleration voltage changes is obtained from the initial data of each standard sensitivity curve stored in the storage unit, and the rate and the rate are calculated. A standard sensitivity value at another acceleration voltage is calculated from an actual measurement value of the standard sensitivity value, and data of a standard sensitivity curve is updated based on the standard sensitivity value and stored in the storage unit.

(4) The data processing program according to the present invention includes an electron beam irradiation unit for irradiating a sample with an electron beam to generate X-rays, and a wavelength dispersion type X-ray for detecting X-rays generated from the sample and acquiring spectrum data. X-ray spectrometer, data of a standard sensitivity curve representing the relationship between the standard sensitivity value and the wavelength of the wavelength dispersive X-ray spectrometer, the standard sensitivity value for each wavelength used for calculating the standard sensitivity curve, and A storage unit for storing, for each acceleration voltage of the electron beam, initial data of the standard sensitivity curve obtained by using one of the representative devices. And causing the computer to execute the updating step. In the standard sensitivity curve calculation step, a standard sensitivity curve representing a relationship between a standard sensitivity value and a wavelength of the wavelength dispersive X-ray spectrometer is calculated. In the updating step, the standard sensitivity value stored in the storage unit is updated based on an actual measurement value of the standard sensitivity value at one acceleration voltage, and stored in the storage unit using the standard sensitivity curve calculation step. While updating the data of the standard sensitivity curve, the rate at which the standard sensitivity value changes when the acceleration voltage changes is obtained from the initial data of each standard sensitivity curve stored in the storage unit, and the rate and the rate are calculated. A standard sensitivity value at another acceleration voltage is calculated from an actual measurement value of the standard sensitivity value, and data of a standard sensitivity curve is updated based on the standard sensitivity value and stored in the storage unit.

  According to the present invention, it is not necessary to update the data of the standard sensitivity curve using the actual measurement value of the standard sensitivity value for each acceleration voltage, so that the work of correcting the data of the standard sensitivity curve can be simplified.

FIG. 1 is a schematic diagram illustrating a configuration example of an EPMA according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating an example of an electrical configuration of the EPMA of FIG. 1. FIG. 9 is a diagram illustrating an example of a correspondence relationship between a condition number m and an acceleration voltage E [m]. FIG. 4 is a diagram showing an example of standard sensitivity data at a certain acceleration voltage E [m]. FIG. 4 is a diagram showing an example of a standard sensitivity curve at each acceleration voltage E [m]. FIG. 9 is a diagram for describing an aspect when updating data of a standard sensitivity curve. FIG. 9 is a diagram for describing an aspect when updating data of a standard sensitivity curve. FIG. 4 is a diagram illustrating an example of a standard sensitivity curve.

1. FIG. 1 is a schematic diagram showing a configuration example of an EPMA 100 according to an embodiment of the present invention. The EPMA (electron beam microanalyzer) 100 is a device for detecting and analyzing X-rays generated from the sample S by placing the sample S in the housing 1 and irradiating the sample S with an electron beam. The EPMA 100 includes a sample stage 3, an electron beam irradiation unit 4, a WDS 6, and the like.

  The sample stage 3 can be displaced along two axes (X axis and Y axis) orthogonal to each other in a horizontal plane and a Z axis in a vertical direction. By controlling the displacement of the sample stage 3, it is possible to adjust the measurement region (the region irradiated with the electron beam) on the surface of the sample S.

  The electron beam irradiation unit 4 includes an electron source 41, a condenser lens 42, a diaphragm 43, an objective lens 45, and the like. The electron beam emitted from the electron source 41 is condensed by the condenser lens 42, the luminous flux is converged by the diaphragm 43, and then is irradiated on the surface of the sample S in the form of a smaller spot on the objective lens 45. X-rays are generated from the surface of the sample S irradiated with the electron beam, and the X-rays enter the WDS 6.

  The WDS 6 is a spectroscope (wavelength dispersive X-ray spectroscope) that utilizes the X-ray diffraction phenomenon, and includes a spectral crystal 61 and an X-ray detector 62. The X-rays from the sample S are split by the splitter crystal 61 as a splitter and are incident on the X-ray detector 62. At this time, by controlling the incident angle of the X-rays on the spectral crystal 61, only the X-rays having a wavelength satisfying the Bragg diffraction condition can be detected by the X-ray detector 62, and the data of the X-ray spectrum can be obtained. . A plurality of WDSs 6 are provided in the housing 1. Thereby, the same number of elements as the number of WDS6 can be analyzed simultaneously.

  The spectral crystal 61 and the X-ray detector 62 are provided movably. Specifically, the spectral crystal 61 can move linearly between a position separated from the sample S and a position close to the sample S. The X-ray detector 62 is movable in accordance with the position of the spectral crystal 61 so that the X-rays separated by the spectral crystal 61 enter. The spectral crystal 61 is scanned from a position (long wavelength side) away from the sample S to a position (short wavelength side) close to the sample S, and an X-ray having a wavelength corresponding to the position of the spectral crystal 61 is detected by the X-ray detector 62. By detection, spectrum data representing the X-ray intensity at each wavelength is obtained. The X-ray intensity is a value proportional to the intensity of X-rays detected by the X-ray detector 62, and is, for example, a count value of X-rays per fixed time in the X-ray detector 62.

2. 2. Electrical Configuration of Electron Beam Microanalyzer FIG. 2 is a block diagram showing an example of the electrical configuration of the EPMA 100 of FIG. The EPMA includes a data processing unit 10, a storage unit 20, a display unit 30, and the like, in addition to the above-described WDS6.

  The data processing unit 10 is an EPMA control device that controls the entire operation of the EPMA 100 including the WDS 6, for example. The data processing unit 10 has a configuration including, for example, a CPU (Central Processing Unit), and performs processing on data input from the WDS 6. The data processing unit 10 functions as a data acquisition processing unit 11, a standard sensitivity curve calculation processing unit 12, an update processing unit 13, an element concentration calculation processing unit 14, a display image generation processing unit 15, and the like when the CPU executes the program. I do.

  The storage unit 20 is configured by, for example, a RAM (Random Access Memory) or a hard disk. The data stored in the storage unit 20 can be rewritten and appropriately updated by the data processing unit 10. The display unit 30 is configured by, for example, a liquid crystal display.

  The data acquisition processing unit 11 performs a process of acquiring data of the X-ray intensity detected by the WDS 6 (data acquisition step). When acquiring the standard sensitivity data, an electron beam is applied to a standard sample having an element concentration of 100%, and X-rays generated from the standard sample are detected by WDS6. At this time, the X-ray intensity data acquired by the data acquisition processing unit 11 is stored in the storage unit 20 as standard sensitivity data. The standard sensitivity data is stored in the storage unit 20 in association with the condition number, and is read from the storage unit 20 using the condition number.

  The standard sensitivity data indicates the relationship between the standard sensitivity value of WDS6 and the wavelength. That is, the storage unit 20 stores the standard sensitivity value for each wavelength. The standard sensitivity value is represented by, for example, the count rate (cps / μA) of the X-ray signal per unit beam current amount. Since the standard sensitivity value differs depending on the acceleration voltage of the electron beam applied to the sample, the standard sensitivity data is stored in the storage unit 20 for each of a plurality of different acceleration voltages. Here, the acceleration voltage means a voltage applied for accelerating electrons, and corresponds to the intensity of an electron beam applied to a sample. Further, since the standard sensitivity value changes depending on the X-ray generation efficiency and the detection efficiency according to the wavelength of WDS6, the standard sensitivity data includes a series (K-ray, (L line, M line) are stored in the storage unit 20.

  The standard sensitivity curve calculation processing unit 12 calculates a standard sensitivity curve representing the relationship between the standard sensitivity value and the wavelength based on the standard sensitivity data acquired by the data acquisition processing unit 11 (standard sensitivity curve calculation step). The standard sensitivity curve is obtained by performing a polynomial approximation by the least squares method using the data of the standard sensitivity values at a plurality of wavelengths. Expressed as a changing curve. The data of the standard sensitivity curve calculated by the standard sensitivity curve calculation processing unit 12 is stored in the storage unit 20 in association with each acceleration voltage of the electron beam.

  Further, in the storage unit 20, data of a standard sensitivity curve previously obtained using one representative device (electron beam microanalyzer) is stored as initial data in association with each acceleration voltage of the electron beam. . The representative device is a device different from the electron beam microanalyzer according to the present embodiment. The initial data of the standard sensitivity curve is always stored in the storage unit 20 without being updated.

  The update processing unit 13 performs a process of updating the data of the standard sensitivity curve stored in the storage unit 20 (update step). As described above, the data of the standard sensitivity curve is stored in the storage unit 20 for each of a plurality of different acceleration voltages. However, when the update processing unit 13 updates the data of the standard sensitivity curve at a certain acceleration voltage, The data of the standard sensitivity curve at other acceleration voltages is also updated and stored in the storage unit 20.

  The update processing unit 13 detects the X-rays generated from the standard sample at one acceleration voltage by the WDS 6, and stores the X-rays in the storage unit 20 based on the actually measured standard sensitivity values acquired by the data acquisition processing unit 11 at this time. The standard sensitivity data and the data of the standard sensitivity curve are updated. Specifically, the standard sensitivity value stored in the storage unit 20 is updated to the actual measured value of the standard sensitivity value based on the actual measured value of the standard sensitivity value at one acceleration voltage. Further, the data of the standard sensitivity curve stored in the storage unit 20 is updated with the data of the standard sensitivity curve calculated by the standard sensitivity curve calculation processing unit 12 based on the measured value of the standard sensitivity value. Further, a rate at which the standard sensitivity value changes when the one acceleration voltage changes to another acceleration voltage is obtained from the initial data of each standard sensitivity curve stored in the storage unit 20. From the measured value of the value, a standard sensitivity value at another acceleration voltage is calculated. Then, the data of the standard sensitivity curve stored in the storage unit 20 is updated based on the calculated standard sensitivity value at another acceleration voltage. Note that the standard sensitivity data and the standard sensitivity curve data are not initially stored in the storage unit 20, but are stored in the storage unit 20 by the first processing of the update processing unit 13. The data is sequentially rewritten and updated after the second time.

  The element concentration calculation processing unit 14 calculates the element concentration of the sample using the data of the standard sensitivity curve stored in the storage unit 20 (element concentration calculation step). When the data of the standard sensitivity curve stored in the storage unit 20 is updated by the update processing unit 13, the element concentration of the sample is calculated using the updated data of the standard sensitivity curve. Specifically, an X-ray generated from a sample (unknown sample) at a predetermined acceleration voltage is detected by the WDS 6, and a peak at each wavelength is determined based on the X-ray intensity data acquired by the data acquisition processing unit 11 at this time. The ratio between the intensity and the standard sensitivity value on the standard sensitivity curve at each wavelength is calculated. Thereby, the concentration (element content) of the element corresponding to each wavelength is calculated as a value corresponding to the ratio calculated at that wavelength.

  The display image generation processing unit 15 can generate a display image representing the concentration of each element calculated by the element concentration calculation processing unit 14, and display the display image on the display unit 30. However, the concentration of each element calculated by the element concentration calculation processing unit 14 is not limited to the configuration displayed on the display unit 30, but may be stored in, for example, the storage unit 20 and output as data as needed. Configuration may be used.

3. Specific Example of Standard Sensitivity Data FIG. 3A is a diagram illustrating an example of a correspondence relationship between the condition number m and the acceleration voltage E [m]. FIG. 3B is a diagram showing an example of the standard sensitivity data at a certain acceleration voltage E [m].

  As shown in FIG. 3A, different condition numbers m are associated with the acceleration voltage E [m] of the electron beam according to the value. For example, an acceleration voltage E [m] = 15 (kV) is associated with the condition number m = 3, and an example of the standard sensitivity data at the acceleration voltage E [m] = 15 (kV) is shown in FIG. 3B. Have been.

  As shown in FIG. 3B, the storage unit 20 associates the standard sensitivity value I_DATA [m] [n] with the wavelength X [m] [n], and stores the acceleration voltage E [ m]. Different data numbers n are assigned to the respective standard sensitivity values I_DATA [m] [n], and the X-ray names NAME [m] [n] are also stored in association with each other. In the present embodiment, by specifying the condition number m and the data number n, the values of the standard sensitivity value I_DATA [m] [n] and the wavelength X [m] [n] at the corresponding acceleration voltage E [m] are calculated. It can be read from the storage unit 20 for each X-ray name NAME [m] [n].

The standard sensitivity curve calculation processing unit 12 reads the standard sensitivity value I_DATA [m] [n] at each wavelength X [m] [n] from the storage unit 20 for each acceleration voltage E [m], and calculates the standard sensitivity curve. I do. For example, the standard sensitivity data I_CURVE (m, X) is calculated by approximating the standard sensitivity data read from the storage unit 20 to a polynomial such as the following equation (1) using the least squares method. Note that A [m], B [m], C [m], and D [m] each represent a standard sensitivity coefficient, and these coefficients are stored in the storage unit 20 as data of a standard sensitivity curve.
I_CURVE (m, X)
= A [m] X ³ + B [m] X ² + C [m] X + D [m] (1)

4. Update of Standard Sensitivity Data FIG. 4A is a diagram showing an example of a standard sensitivity curve at each acceleration voltage E [m]. When the standard sensitivity curve is calculated by the above equation (1) based on the standard sensitivity data at each acceleration voltage E [m] (m = 1, 2, 3, 4) stored as an initial value in the storage unit 20, As shown in FIG. 4A, standard sensitivity curves I_CURVE (1, X) and I_CURVE (2) at E [1] = 5 kV, E [2] = 10 kV, E [3] = 15 kV, and E [4] = 20 kV, respectively. , X), I_CURVE (3, X), and I_CURVE (4, X).

  FIG. 4B and FIG. 4C are diagrams for explaining aspects when updating the data of the standard sensitivity curve. When updating the data of the standard sensitivity curve, the acceleration voltage E stored in the storage unit 20 based on the actual measurement value of the standard sensitivity value acquired at the acceleration voltage E [M] under a certain condition number m = M. The standard sensitivity value in [M] is updated, and the data of the standard sensitivity curve calculated by the standard sensitivity curve calculation processing unit 12 based on the standard sensitivity value is stored and updated in the storage unit 20, and the calculation described later is performed. The data of the standard sensitivity curve at another acceleration voltage E [m] calculated by the above is stored in the storage unit 20 and updated.

  For example, as shown in FIG. 4B, it is assumed that the actual measurement value of the standard sensitivity value acquired at the acceleration voltage E [M] is I_DATA_correct [M] [n] at a certain wavelength X_correct [M] [n]. Further, the standard sensitivity value (initial value) on the standard sensitivity curve at the acceleration voltage E [M] at this wavelength X_correct [M] [n] is I_CURVE_init (M, X_correct [M] [n]). It is assumed that the standard sensitivity value (initial value) on the standard sensitivity curve at the acceleration voltage E [m] is I_CURVE_init (m, X_correct [m] [n]).

In this case, the standard sensitivity value I_DATA_correct [m] [n] at another acceleration voltage E [m] is updated by the following equation (2).
I_DATA_correct [m] [n]
= I_DATA_correct [M] [n] × R (2)
Note that R is a rate at which the standard sensitivity value changes when the acceleration voltage changes from E [M] to E [m]. From the initial data of the standard sensitivity curve stored in the storage unit 20, the following equation is used. It is determined by (3).
R = I_CURVE_init (m, X_correct [m] [n])
÷ I_CURVE_init (M, X_correct [M] [n])
... (3)

  As shown in FIG. 4B, such an operation is performed based on the actual measurement value I_DATA_correct [M] [n] of the standard sensitivity value at each wavelength, and thereby, the updated standard sensitivity value I_DATA_correct [m at each wavelength. ] [N] is obtained. Thereafter, as shown in FIG. 4C, the data I_CURVE_correct (M, X) of the standard sensitivity curve at the acceleration voltage E [M] is updated in accordance with the actual measurement value I_DATA_correct [M] [n] of the standard sensitivity value at each wavelength. In addition, the data I_CURVE_correct (m, X) of the standard sensitivity curve at another acceleration voltage E [m] is updated in accordance with the updated standard sensitivity value I_DATA_correct [m] [n] at each wavelength.

  That is, based on the actual measurement value I_DATA_correct [M] [n] of the standard sensitivity value at each wavelength, I_CURVE_correct (M, X) is obtained by performing an operation approximating to a polynomial such as the above equation (1). , The coefficients A_correct [M], B_correct [M], C_correct [M], and D_correct [M] in the polynomial are stored in the storage unit 20, so that the data I_CURVE_correct (M) of the standard sensitivity curve at the acceleration voltage E [M] is stored. , X) are updated. Further, based on the updated standard sensitivity value I_DATA_correct [m] [n] at each wavelength, an operation approximating a polynomial such as the above equation (1) is performed, so that I_CURVE_correct (m, X) is obtained. By storing the coefficients A_correct [m], B_correct [m], C_correct [m], and D_correct [m] in this polynomial in the storage unit 20, the data I_CURVE_correct of the standard sensitivity curve at another acceleration voltage E [m] is stored. (M, X) is updated.

  The predetermined acceleration voltage E [M] and the other acceleration voltage E [m] may be fixed values set in advance or may be arbitrarily selected by the user. However, the initial data of the standard sensitivity curve must be under acceleration voltage conditions under which the standard sensitivity value does not become 0 or less within the wavelength range of X-rays detected by WDS6 (within the spectral wavelength range). For example, in the example shown in FIG. 4A, the condition is satisfied if the acceleration voltage is 15 kV or more.

5. Calculation of updated element concentration If the data of the standard sensitivity curve is updated, the element concentration of the sample is calculated using the updated data of the standard sensitivity curve. That is, when the qualitative analysis is performed with the acceleration voltage E [m], each wavelength is determined based on the ratio between the updated standard sensitivity curve I_CURVE_correct (m, X) and the measured peak intensity at each wavelength. The corresponding element concentration (element content) is calculated.

  At this time, for example, when qualitative analysis is performed under an acceleration voltage condition between E [m] and E [m + 1], a standard sensitivity curve I_CURVE_correct (m, X) at the acceleration voltage E [m] and the acceleration voltage E The standard sensitivity value at each wavelength is calculated by performing linear interpolation between the standard sensitivity curve I_CURVE_correct (m + 1, X) at [m + 1]. In this case, the concentration (element content) of the element corresponding to each wavelength is calculated based on the ratio between the calculated standard sensitivity value at each wavelength and the measured peak intensity at each wavelength.

6. Operation and Effect (1) In the present embodiment, the standard sensitivity curve at another acceleration voltage E [m] is obtained by using the actually measured value I_DATA_correct [M] [n] of the standard sensitivity value acquired at one acceleration voltage E [M]. Data of I_CURVE_correct (m, X) can be updated collectively. Therefore, for each acceleration voltage E [m], there is no need to update the data of the standard sensitivity curve using the actual measurement value of the standard sensitivity value, so that the work of correcting the data of the standard sensitivity curve can be simplified.

  When only the acceleration voltage E [m] is changed for the same X-ray measurement, the measured standard sensitivity value does not depend on the detection efficiency of WDS6 but changes only depending on the X-ray generation efficiency. Therefore, when the same standard sensitivity value of X-rays is obtained under different acceleration voltage conditions, the mutual ratio is considered to be the same value without depending on the individual difference of the device or the component. For this reason, if the ratio is calculated using a standard sensitivity curve for each acceleration voltage obtained in advance using one representative device, it is only necessary to update the standard sensitivity value under one acceleration voltage condition. The standard sensitivity value of E [m] can be corrected to an appropriate value, and the standard sensitivity curve can be updated.

(2) In the present embodiment, the element concentration of the sample can be calculated using the data of the standard sensitivity curve I_CURVE_correct (m, X) at each of the accelerating voltages E [m] updated collectively. Therefore, the element concentration of the sample can be easily calculated using the data of the standard sensitivity curve I_CURVE_correct (m, X) for each acceleration voltage obtained by the simplified operation.

7. Modified Example In the above embodiment, the EPMA 100 including the data processing unit 10 has been described. However, a program (data processing program) for causing a computer to function as the data processing unit 10 may be provided. In this case, the program may be provided in a state of being stored in a storage medium, or may be provided such that the program itself is provided via wired communication or wireless communication. .

Reference Signs List 1 housing 3 sample stage 4 electron beam irradiation unit 6 WDS (wavelength dispersive X-ray spectrometer)
Reference Signs List 10 Data processing unit 11 Data acquisition processing unit 12 Standard sensitivity curve calculation processing unit 13 Update processing unit 14 Element concentration calculation processing unit 15 Display image generation processing unit 20 Storage unit 30 Display unit 41 Electron source 42 Condenser lens 45 Objective lens 61 Spectral crystal 62 X-ray detector 100 EPMA (Electron beam micro analyzer)

Claims (4)

An electron beam irradiation unit that irradiates the sample with an electron beam to generate X-rays;
A wavelength-dispersive X-ray spectrometer that detects X-rays generated from the sample and acquires spectral data,
A standard sensitivity curve calculation processing unit that calculates a standard sensitivity curve representing a relationship between a standard sensitivity value and a wavelength of the wavelength dispersive X-ray spectrometer,
The data of the standard sensitivity curve calculated by the standard sensitivity curve calculation processing unit, the standard sensitivity value for each wavelength used for the calculation of the standard sensitivity curve, and the standard sensitivity curve previously obtained using one representative device A storage unit for storing the initial data of each electron beam accelerating voltage,
Based on the measured value of the standard sensitivity value at one acceleration voltage, the standard sensitivity value stored in the storage unit is updated, and the standard value stored in the storage unit is updated using the standard sensitivity curve calculation processing unit. While updating the sensitivity curve data, the rate at which the standard sensitivity value changes when the acceleration voltage changes is obtained from the initial data of each standard sensitivity curve stored in the storage unit, and the rate and the standard sensitivity value are calculated. An electron beam, comprising: calculating a standard sensitivity value at another acceleration voltage from an actual measurement value, updating the data of the standard sensitivity curve based on the standard sensitivity value, and storing the updated data in the storage unit. Micro analyzer.   The electron beam microanalyzer according to claim 1, further comprising an element concentration calculation processing unit that calculates an element concentration of the sample using the data of the standard sensitivity curve updated by the update processing unit. An electron beam irradiator for irradiating a sample with an electron beam to generate X-rays, a wavelength dispersive X-ray spectrometer for detecting X-rays generated from the sample and acquiring spectrum data, and the wavelength dispersive X-ray spectrometer Data of a standard sensitivity curve representing the relationship between the standard sensitivity value of the instrument and the wavelength, the standard sensitivity value for each wavelength used for calculating the standard sensitivity curve, and the standard sensitivity previously obtained using one representative apparatus A data processing method used for an electron beam microanalyzer including a storage unit that stores initial data of a curve for each acceleration voltage of an electron beam,
A standard sensitivity curve calculating step of calculating a standard sensitivity curve representing a relationship between a standard sensitivity value and a wavelength of the wavelength dispersive X-ray spectrometer;
The standard sensitivity value stored in the storage unit is updated based on the actual measurement value of the standard sensitivity value at one acceleration voltage, and the standard sensitivity value stored in the storage unit is calculated using the standard sensitivity curve calculation step. While updating the curve data, the rate at which the standard sensitivity value changes when the acceleration voltage changes is obtained from the initial data of each standard sensitivity curve stored in the storage unit, and the rate and the standard sensitivity value are measured. Calculating a standard sensitivity value at another acceleration voltage from the value, updating the data of the standard sensitivity curve based on the standard sensitivity value, and storing the updated data in the storage unit. An electron beam irradiator for irradiating a sample with an electron beam to generate X-rays; a wavelength dispersive X-ray spectrometer for detecting X-rays generated from the sample and acquiring spectrum data; Of a standard sensitivity curve representing the relationship between the standard sensitivity value of the device and the wavelength, the standard sensitivity value for each wavelength used for calculating the standard sensitivity curve, and the standard sensitivity previously obtained using one representative apparatus A data processing program used for an electron beam microanalyzer including a storage unit that stores initial data of a curve for each acceleration voltage of an electron beam,
A standard sensitivity curve calculating step of calculating a standard sensitivity curve representing a relationship between a standard sensitivity value and a wavelength of the wavelength dispersive X-ray spectrometer;
The standard sensitivity value stored in the storage unit is updated based on the measured value of the standard sensitivity value at one acceleration voltage, and the standard sensitivity value stored in the storage unit is calculated using the standard sensitivity curve calculation step. While updating the curve data, the rate at which the standard sensitivity value changes when the acceleration voltage changes is obtained from the initial data of each standard sensitivity curve stored in the storage unit, and the rate and the actual measurement of the standard sensitivity value are obtained. Calculating a standard sensitivity value at another acceleration voltage from the value, updating the data of the standard sensitivity curve based on the standard sensitivity value, and storing the updated data in the storage unit. Processing program.

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