JPH10318946A - Energy dispersion type x-ray analysis device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray analysis device for obtaining an appropriate analysis result quickly. SOLUTION: In an X-ray analysis device, the minimum peak interval between an element where a content in a sample is to be measured and another element in the sample is obtained by a peak interval acquisition part 17 when the calibration curve expression quantitative analysis method is specified and at the same time a time constant that matches the minimum resolution where the noticed peak of the element where the content is to be measured can be separated by a time constant selection part 18, and the time constant of a shaping circuit 10 is set to a time constant that is selected by the time constant selection part 18 by a time constant setting part 11. Since a time constant that is longer than as required cannot be set, the reading rate of an X-ray detection signal becomes fully high and an accurate content can be measured quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy dispersive X-ray analyzer for detecting a characteristic X-ray emitted from an excited sample by a semiconductor (X-ray) detector and performing elemental analysis of the sample, and in particular, to an energy dispersive X-ray analyzer. The present invention relates to a technique for reducing analysis time.

[0002]

2. Description of the Related Art A conventional energy dispersive X-ray fluorescence analyzer uses a semiconductor X-ray detector to detect a characteristic X-ray emitted from a sample excited by irradiation with a primary X-ray, and then performs a waveform shaping circuit and the like. Is input to the multi-channel analyzer as an X-ray detection signal via the LM, and an energy spectrum is obtained by performing a discrimination process according to the wave height, and an elemental analysis of the sample is performed by data processing based on the obtained energy spectrum. It has become.

More specifically, a signal output from a semiconductor X-ray detector is amplified by a preamplifier (preamplifier) to a certain extent and then further amplified by a proportional amplifier. The circuit is included in a proportional amplification circuit, and is shaped into a pulse of an appropriate shape having a peak according to the energy value of the characteristic X-ray by a waveform shaping circuit, and is sent to a multi-channel analyzer as an X-ray detection signal. The multi-channel analyzer discriminates and calculates the X-ray detection signal according to the wave height to obtain a wave height distribution map (energy spectrum). In this energy spectrum, a peak unique to each element appears at a position corresponding to the energy value of characteristic X-rays emitted from the element contained in the sample. Then, the positions (energy) and intensities of these peaks are obtained by data processing such as peak separation, and elemental analysis of those samples is performed. Normally, a sample containing unknown elements is measured. Therefore, in order to facilitate data processing, it is desirable to use measurement conditions that provide as high a resolution as possible. However, in actuality, in consideration of the problem of the measurement time described below, conditions are selected so that the measurement time is practical and the resolution is sufficient.

[0004]

However, in the case of the above-mentioned conventional X-ray analyzer, there is a problem that the analysis time is lengthened in order to obtain a high resolution. The reason will be described below. That is, in order to reduce the noise superimposed on the signal output from the semiconductor X-ray detector in order to obtain a high resolution, it is necessary to make the time constant of the waveform shaping circuit as long as possible. However, when the time constant of the waveform shaping circuit is increased, the probability that a so-called pile-up phenomenon occurs in which adjacent pulses interfere with each other and become apparently one pulse increases. Pulses that interfere in this manner are usually excluded from counting by a pile-up removal circuit. As a result, the rate of capturing the X-ray detection signal into the multi-channel analyzer decreases.

On the other hand, in an X-ray analyzer, a certain number or more of X-ray detection signals have to be taken into a multi-channel analyzer due to the necessity of suppressing errors due to statistical fluctuation of X-rays. Therefore, when the rate of capturing the X-ray detection signal decreases as described above,
Since the required number of X-ray detection signals are taken by increasing the line measurement time, the analysis time is increased. In addition,
Normally, if the number of primary X-rays increases, the X-ray detection signal should also increase in proportion. However, if the time constant of the waveform shaping circuit is long, the number of occurrences of the pile-up phenomenon increases and is eliminated. Since the number of pulses increases, the amount of X-ray detection signals captured does not increase, and does not necessarily lead to a reduction in analysis time.

[0006] In view of the above problems, the present invention provides an energy dispersive X-ray detector capable of obtaining an appropriate analysis result in a short time.
It is an object to provide a line analyzer.

[0007]

In order to achieve the above object, an energy dispersive X-ray analyzer according to the present invention is a semiconductor X-ray detector for detecting X-rays emitted from an excited sample. A waveform shaping circuit for shaping a signal output from the semiconductor X-ray detector into a pulse wave; and a multi-channel for obtaining an energy spectrum (pulse wave high frequency distribution diagram) of the X-ray detection signal input through the waveform shaping circuit. An energy dispersive X-ray analyzer that includes an analyzer and a data processing unit that performs elemental analysis of the sample by performing data processing based on the energy spectrum obtained by the multi-channel analyzer,
An analysis method designating means for designating an analysis method for elemental analysis is provided, and a time constant setting means for setting a time constant of the waveform shaping circuit in accordance with the analysis method designated by the analysis method designating means.

According to a second aspect of the present invention, in the energy dispersive X-ray analyzer according to the first aspect, the analysis method designating means is configured to be able to designate at least a calibration curve method as an analysis method, and to set a time constant. The means is configured so that a time constant selected from a plurality of time constants can be further set when a calibration curve method is designated, and an energy spectrum is provided for each of all elements to which the calibration curve method is applied. Holding the peak position data indicating the position (energy value) of each peak and the minimum peak interval data indicating the correspondence between the energy value and the minimum separable peak interval for each of the plurality of time constants. Means, the peak of the element whose content is to be measured in the sample (target element) based on the peak position data, and the peaks of other contained elements in the sample. Peak interval calculating means for calculating the shortest shortest peak interval among the intervals, and the necessary peak separation is possible by comparing the shortest peak interval and the minimum peak interval data determined by the peak interval determining means. A time constant selecting means for selecting the shortest time constant among the time constants as a set time constant of the waveform shaping circuit.

[Operation] The operation of the energy dispersive X-ray analyzer (hereinafter abbreviated as “X-ray analyzer” as appropriate) of the present invention for performing elemental analysis of a sample will be described.
In the case of elemental analysis by the X-ray analyzer according to claim 1, first, when an analysis method of elemental analysis is designated by the analysis method designation means,
The time constant of the waveform shaping circuit is automatically set according to the analysis method specified by the time constant setting means. Next, primary X
After the X-rays emitted from the sample excited by the irradiation of the line or the electron beam are detected by the semiconductor X-ray detector, they are sequentially input to the multi-channel analyzer as X-ray detection signals through a waveform shaping circuit. In the multi-channel analyzer, the X-ray detection signal is discriminated according to the wave height, and an energy spectrum is obtained. When the energy spectrum is obtained, the data processing means specifies the element from the energy value of the peak appearing in the energy spectrum according to the specified analysis method (qualitative analysis).
Or the area of the peak is determined, and the content of the element is determined (quantitative analysis) based on the area, and the elemental analysis is advanced.

[0010] The time constant of the waveform shaping circuit set by the time constant setting means of the X-ray analyzer according to the present invention substantially corresponds to the minimum resolution required for appropriately executing the specified analysis method. The time constant of the waveform shaping circuit is automatically set to the shortest possible time constant, and the time constant of the waveform shaping circuit is not set longer than necessary. Therefore, the acquisition rate of the X-ray detection signal in the multi-channel analyzer is reduced more than necessary. Such a thing disappears.

In the X-ray analyzer according to the present invention, when the calibration method is designated by the analysis method designating means, the designation of the element contained in the present sample (unknown sample) to be quantitatively analyzed, if necessary, Also performed), by the peak interval finding means,
In this case, the shortest shortest peak interval among the intervals between the peak of interest (for content measurement) of the element whose content is to be measured among the elements contained in the sample and the peaks of other elements in the sample is determined. Next, the time constant selecting means illuminates the shortest peak interval and the minimum peak interval data indicating the correspondence between the energy value and the minimum separable minimum peak interval for each of the plurality of time constants prepared for the calibration curve method. The shortest time constant among the time constants at which the required peak separation is possible is selected as the set time constant of the waveform shaping circuit. Then, after the time constant of the waveform shaping circuit is set to the time constant immediately selected by the time constant setting means, the energy spectra of the standard sample and the unknown sample are obtained according to the normal procedure of the calibration curve method. Then, a calibration curve is created from the measurement results of the standard sample by the data processing means, and the content of the element to be quantitatively measured in the unknown sample is determined using the calibration curve.

In the case of the calibration curve method using the X-ray analyzer according to the second aspect, the time constant of the waveform shaping circuit is a minimum necessary length corresponding to the shortest peak interval between the limited elements constituting the sample this time. The time constant is automatically set, and a time constant longer than necessary is not set, so that the rate of capturing the X-ray detection signal in the multi-channel analyzer is sufficiently ensured.

[0013]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of a fluorescent X-ray analyzer according to an embodiment, and FIG. 2 is a partial block diagram showing the configurations of a waveform shaping circuit and a time constant setting unit in the embodiment. As shown in FIG. 1, the fluorescent X-ray analyzer of the embodiment includes a measurement main body SA that excites a sample SM by primary X-rays and detects characteristic X-rays emitted from the sample SM. A control processing unit SB for processing the transmitted signal and performing necessary control for the measurement main unit SA and the like. Hereinafter, the configuration of each unit will be specifically described.

The measurement main body SA has a sample chamber 1 into which a sample SM to be measured is introduced, and a stage (sample stage) 2 on which the sample SM is set is provided in the sample chamber 1. X-ray tube 3 for irradiating primary X-ray to sample SM
And the characteristic X emitted from the sample SM excited by the primary X-ray
Semiconductor X-ray detector 4 for detecting X-rays and a preamplifier (preamplifier) for amplifying the output of X-ray detector 4 to a certain extent
5 is installed near the sample chamber 1. The irradiation operation of the X-ray tube 3 is usually controlled from the control processing unit SB. Further, as the semiconductor X-ray detector 4, a Li-compensated Si (Li) X-ray detector or the like is used. And X
The line detector 4 is always cooled by liquid nitrogen contained in a thermos container (Dewar) 6 together with the preamplifier 5 and is maintained at a very low temperature.

The control processing unit SB includes a proportional amplifier 7 for shaping and amplifying a signal sent from the preamplifier 5, digitizing an analog output signal of the proportional amplifier 7, and converting a peak value thereof to a multi-channel analyzer (MCA) 9. And an MCA 9 that obtains an energy spectrum (pulse wave frequency distribution diagram) by discriminating the wave height information successively sent from the AD converter 8 according to the magnitude thereof in a series. Is provided. In the case of the fluorescent X-ray analyzer of the embodiment, the waveform shaping circuit 10 for shaping the proportional amplifier 7 into an appropriate pulse waveform and the waveform shaping circuit 10
A time constant setting unit 11 for setting the time constant is provided.

The time constant setting unit 11 for setting the time constant of the waveform shaping circuit 10 includes n feedback impedances Z1 to Zn and one changeover switch 11 as shown in FIG.
a, and one of the n feedback impedances Z1 to Zn is changed by the changeover switch 11a to the waveform shaping circuit 1.
When connected in parallel with 0, the time constant of the waveform shaping circuit 10 is set to one of the time constants τ1 to τn. Which time constant among the time constants τ1 to τn is selected and set depends on the specified analysis method, the type of the element to be analyzed, and the like, and will be described later in detail. Note that the time constant τ1 is the longest time, and the time becomes shorter in order, and the time constant τn is the shortest time.

The signal sent from the preamplifier 5 to the proportional amplifier 7 is added to the shaping function of the waveform shaping circuit 10,
The pulse is amplified and shaped into an appropriately shaped pulse having a wave height proportional to the energy value (peak position) of the characteristic X-ray and output. At this time, noise superimposed on the input signal is removed. The AD converter 8 converts the pulse signal sent from the proportional amplifier 7 into a digital signal (for example, a 10-bit digital signal) having a magnitude corresponding to the wave height, and sends it to the MCA 9 as an X-ray detection signal. In the MCA 9, the number of bits of the AD converter 8 (the number of digital signals of different sizes)
The number of channels (for example, 1024 channels in the case of a 10-bit digital signal) is prepared in advance, and the X-ray detection signals sent one after another are set for each channel according to the magnitude (of the digital signal). And the number (frequency) of X-ray detection signals entering each channel per unit time is counted.

Then, an energy spectrum is obtained in which the channel position (that is, the energy value) is set as the horizontal axis and the counting result in each channel is set as the vertical axis. For example, as shown in FIG. 3, five peaks PK1 to PK5 are energy values (peak positions) E1.
The energy spectra appearing in E5 to E5 are obtained. Of course, each of the energy values E1 to E5 corresponds to the energy value of the characteristic X-ray of the element.

Further, the control processing unit SB is a data processing unit 12 for performing elemental analysis of the sample by data processing based on the energy spectrum obtained by the MCA 9, and for specifying an analysis method and an element at the time of analysis. An operation unit (analysis method designating unit) 13, a display unit 30 for displaying an energy spectrum and an elemental analysis result, a control program storage unit 14 for storing a control program for controlling the operation of the entire apparatus, and the like are provided. The data processing unit 12 has a central processing unit (CPU) for transmitting necessary command signals and executing necessary calculations according to a control program.
15 are provided.

Examples of the analysis method that can be specified by the operation unit 13 of the embodiment apparatus include a calibration curve method and a so-called FP
And a fundamental parameter type quantitative analysis method (FP type quantitative analysis method), which is commonly referred to as a method. In the former calibration curve method, as is conventionally known, a standard sample (for example, a stainless steel sample with a known content) having almost the same composition as the unknown sample (for example, a stainless steel sample with unknown content) and slightly different element contents from each other is used. This is effective when measuring the content of a specific element (target element) in an unknown sample when there are a plurality of them. Specifically, for example, an energy spectrum for each standard sample is obtained, and the data processing unit 12 obtains a target peak of the target element (usually, the Kα peak or L
The relationship between the peak area and the content of the (α peak) is measured to obtain a calibration curve, the energy spectrum of an unknown sample is obtained, and the peak area of the peak of interest of the target element is obtained by the data processing unit 12 to obtain a calibration curve. By applying, the content of the target element in the unknown sample is determined.

In the latter FP-type quantitative analysis method, as is conventionally known, there is no standard sample, only an unknown sample (for example, a mineral sample whose content is unknown), and the content of each element is measured. This is effective in such cases. Specifically, the energy spectrum of an unknown sample is
After all the peaks of interest of all elements can be separated by data processing, the intensity of each peak of interest is obtained by data processing, and the content of each element in the sample is obtained from the intensity by the FP method. .

In the case of the embodiment, the data processing unit 1
2 is provided with a data holding unit 16 for preliminarily storing and holding data necessary for executing various specifiable analysis methods, a peak interval finding unit 17 and a time constant selecting unit 18. Further, the data holding unit 16 includes a peak position data memory 19, a peak waveform data memory 20, a minimum peak interval data memory 21, and a quantitative analysis related data memory 2.
2 is provided.

The peak position data memory 19 stores peak position data indicating the position (energy value) of each peak in the energy spectrum for each of the elements to which the calibration curve method may be applied. Specifically, as shown in FIG. 4, element names, element numbers, energy values, and characteristic X-ray names are stored. The peak waveform data memory 20 stores the peak ratio of characteristic X-rays of the same element (for example, the ratio of the Kα peak of the Fe element to the Kβ peak of the Fe element) as peak waveform data. The minimum peak interval data memory 21 stores the minimum peak interval data indicating the correspondence between the energy value and the separable minimum peak interval for each of the time constants τ1 to τn set by the waveform shaping circuit 10. The quantitative analysis related data memory 22 stores measurement data and calibration curve data of a standard sample for the calibration curve method.

The minimum peak interval data of each data is
Although the data is used in the case of the calibration curve method, it is also characteristic data of the present invention, and thus will be described more specifically. That is, as shown in FIG.
Is stored as a parameter in the minimum peak interval data memory 21 in the form of a table or a mathematical expression, with the horizontal axis representing the energy value (peak position) and the vertical axis representing the minimum separable peak interval.

Next, the peak interval calculating section 17 and the time constant selecting section 18 will be described. In the case of the calibration curve method, it is only necessary that the peak of interest of the element whose content is to be measured can be separated from the peaks of other contained elements in the sample. Elements that are not included in the sample need not be considered. In the case of this calibration curve method, even if it is an unknown sample, only the types of the contained elements are known, so the peak interval calculating unit 17 calculates the peak of interest of the element whose content is to be measured and other contained elements in the sample. The peak interval is calculated with reference to the peak position data, and the shortest shortest peak interval is selected. Hereinafter, the target peak will be described as the energy value Ei and the shortest peak interval di.

When the shortest peak interval di is determined by the peak interval determining section 17, the time constant selecting section 18 checks the shortest peak interval di and the minimum peak interval data as shown in FIG. Then, the shortest time constant τi among the time constants at which the minimum peak interval at the energy value Ei is equal to or less than the shortest peak interval di is selected. The result of the selection by the time constant selecting unit 18 is immediately sent to the time constant setting unit 11, where the changeover switch 11a connects the feedback impedance Zi to the waveform shaping circuit 10 in parallel, and the time constant Set to a constant τi. The peak interval calculating section 17 and the time constant selecting section 18 are configured by a control program, a microcomputer, and the like.

When the FP quantitative analysis method is designated as the analysis method, the time constant setting unit 11 automatically sets a predetermined time constant (for example, a relatively long time constant τ ₂ ). It has a configuration. In the case of the FP quantitative analysis method, a high resolution (that is, a resolution sufficient for performing data processing (peak separation)) is required even if the rate of capturing the X-ray signal is sacrificed to some extent. Is set.

Next, the operation of the X-ray fluorescence analyzer having the above-described configuration when performing elemental analysis will be described with reference to the flowchart showing the flow of setting the time constant of the waveform shaping circuit. First, the following operation is performed by the operator. An analysis method (either the calibration curve method or the FP quantitative analysis method in this embodiment) is designated from the operation unit 13. F
When the P-type quantitative analysis method is specified, a predetermined relatively long time constant is set in order to increase the resolution as much as possible. Subsequently, an unknown sample MS whose content is to be measured is set on the stage 2 of the sample chamber 1, and qualitative / quantitative analysis of the unknown sample MS is performed.

On the other hand, when the calibration curve method is instructed, all types of elements contained in the sample MS are input from the operation unit 13. Now, the element A whose content is to be measured in the sample MS and the sample M
It is assumed that other contained elements B and C in S are present. Then, an instruction to start the analysis operation (start) is also instructed from the operation unit 13.

First, peak position data of the elements A to C are extracted from the peak position data memory 19 by the peak interval calculating section 17, and the Kα peak of the element A (peak of interest) and the elements B, After the interval between each peak of C is calculated, the shortest shortest peak interval di among them is selected.

Following the selection of the shortest peak interval di, the time constant selecting section 18 compares the shortest peak interval di with the minimum peak interval data to make the minimum peak interval at the energy value Ei the shortest as shown in FIG. After the shortest time constant τi among the time constants having the peak interval di or less is selected, the selection result is sent to the time constant setting unit 11. here,
The reason for selecting the shortest time constant τi among the time constants at which the minimum peak interval at the energy value Ei is equal to or less than the shortest peak interval di is that, among the time constants giving the required resolution, the shortest is the pile-up. This is because the probability of occurrence is small and the capture rate can be increased. In the time constant setting unit 11 receiving the selection result of the time constant, the changeover switch 1
1a, the feedback impedance Zi is changed by the waveform shaping circuit 10
And the time constant of the waveform shaping circuit 10 is a time constant τ
Set to i. Then, in order to create a calibration curve, a plurality of standard samples SM with known contents are sequentially set on the stage 2 of the sample chamber 1 and measurement is performed for each of them.

That is, as the sample SM is irradiated with the primary X-ray for excitation from the X-ray tube 3, the excited sample S
Characteristic X-rays emitted from M are detected by the X-ray detector 4 and an energy spectrum is obtained by the MCA 9. As described above, when the energy spectrum of each standard sample is obtained, the central processing unit 15 calculates the Kα of the element A.
The area of the peak is determined. Then, a content-intensity relational expression (calibration curve data) is created and stored in the data memory 22. At this time, if, for example, the Kα peak of the element A and the (for example) Kβ peak of the element A are not separated, they can be processed as one peak. That is, the same energy region may be used as the peak region when the calibration curve is created and when the unknown sample is measured, and it is not always necessary to separate them. Therefore, when selecting the shortest peak interval di, the element A other than the Kα peak of the element A
Other peaks need not be considered.

After preparing the calibration curve, the unknown sample is measured,
The area of the Kα peak of the obtained element A is
Is compared with the calibration curve data stored in the quantitative analysis related data memory 22 to determine the content of the element A, and when the analysis result is displayed on the display 30, the element analysis ends.

As described above, in the case of the calibration curve type quantitative analysis by the apparatus of the embodiment, the time constant of the waveform shaping circuit is required to be a minimum corresponding to the shortest peak interval di between the limited elements constituting the sample SM. Is automatically set to a time constant of
Since an unnecessarily long time constant is not set, the elemental analysis can be completed in a short time.

The present invention is not limited to the above embodiment, but can be modified as follows. (1) Although the X-ray analyzer of the embodiment is an X-ray excitation type X-ray analyzer that excites a sample with primary X-rays, an electron excitation type X-ray that excites the sample with an electron beam (electron flow) is used. A line analyzer is mentioned as a modification. In the case of the electronic excitation type X-ray analyzer of the modified example, an analysis method corresponding to the FP type quantitative analysis method is called a ZAF type quantitative analysis method.

(2) In the embodiment, the shortest peak interval d
When selecting i, other peaks of the element A other than the Kα peak of the element A do not need to be considered, but in addition to the other peaks, the peaks of the element A other than the Kα peak of the element A are also considered. The configuration is also a modification.

(3) In the apparatus of the embodiment, the time constant of the waveform shaping circuit is set discretely, but a configuration in which the time constant of the waveform shaping circuit can be set continuously is mentioned as a modified example. Can be

[0038]

According to the energy dispersive X-ray analyzer according to the first aspect of the present invention, the time constant of the waveform shaping circuit for adjusting the waveform of the signal obtained from the X-ray detector is practically specified. The time constant of the waveform shaping circuit is automatically set to the shortest possible time constant that matches the minimum required resolution to properly execute, and the time constant of the waveform shaping circuit is prevented from becoming unnecessarily long. The rate of capturing the X-ray detection signal in the multi-channel analyzer does not decrease unnecessarily, and an appropriate analysis result can be obtained in a short time.

According to the energy dispersive X-ray analyzer of the second aspect, the time constant of the shaping circuit is a minimum necessary length corresponding to the shortest peak interval between the limited elements constituting the sample. The time constant is automatically set to the time constant, and the time constant longer than necessary is not set. As a result, the acquisition rate of the X-ray detection signal is sufficiently secured, and the element whose content is to be measured in the sample is determined. Can be accurately measured in a short time.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall configuration of a fluorescent X-ray analyzer according to an embodiment.

FIG. 2 is a partial block diagram illustrating a waveform shaping circuit and a time constant setting unit in the apparatus according to the embodiment.

FIG. 3 is a graph showing an example of an energy spectrum obtained by the apparatus according to the embodiment.

FIG. 4 is a schematic diagram showing the contents of an example of peak position data held in the embodiment device.

FIG. 5 is a graph for explaining minimum peak interval data held in the embodiment device.

FIG. 6 is a flowchart illustrating a flow of setting a time constant of a shaping circuit in the apparatus according to the embodiment.

[Explanation of symbols]

 4 semiconductor X-ray detector 9 multi-channel analyzer 10 waveform shaping circuit 11 time constant setting unit 13 operation unit 16 data holding unit 19 peak position data memory 21 minimum peak interval data memory di shortest peak interval τ1-τn: time constant SM: sample

Claims (2)

[Claims] 1. A semiconductor X-ray detector for detecting X-rays emitted from an excited sample, a waveform shaping circuit for shaping a signal output from the semiconductor X-ray detector into a pulse wave, and the waveform shaping circuit. A multi-channel analyzer that obtains the energy spectrum (pulse wave high frequency distribution diagram) of the X-ray detection signal input through the device, and performs elemental analysis of the sample by data processing based on the energy spectrum obtained by the multi-channel analyzer An energy dispersive X-ray analyzer having data processing means, comprising an analysis technique designating means for designating an analysis technique of elemental analysis, and a waveform shaping circuit according to the analysis technique designated by the analysis technique designating means. Energy dispersive X-ray analysis, comprising time constant setting means for setting a time constant apparatus. 2. The energy dispersive X-ray analyzer according to claim 1, wherein the analysis method designating means is configured to specify at least a calibration curve method as an analysis method, and the time constant setting means designates the calibration curve method. In this case, a time constant selected from a plurality of time constants can be set, and the position of each peak (energy Data holding means for holding peak position data indicating the peak value and the minimum peak interval data indicating the correspondence between the energy value and the minimum separable peak interval for each of the plurality of time constants. The shortest and shortest distance between the peak of the element (target element) whose content is to be measured in the sample and the peak of the other element in the sample Peak interval calculating means for calculating the peak interval, and the shortest time constant among the time constants at which necessary peak separation is possible by comparing the shortest peak interval and the minimum peak interval data determined by the peak interval determining means. An energy dispersive X-ray analyzer comprising a time constant selecting means for selecting a constant as a setting time constant of a waveform shaping circuit.