JPS59214743A - X-ray analyzing apparatus - Google Patents

Abstract

PURPOSE:To measure the peak strength excluding a background component in a short time, by multiplying a counted value at a wavelength in the vicinity of a wavelength selected by a spectroscope by a specified ratio, and subtracting the resultant value from the counted value of the detected pulses of an X-ray detector. CONSTITUTION:An X ray having a wavelength lambdao is selectively detected by an X-ray detector 8. Pulses are counted only during a time T. The X-rays generated from a sample 6 are simultaneously detected by a semiconductor detector 14 and counted at every energy region. An electronic computer 12 obtains a measured value Be' of a background expressed by the expression in the Figure from a wavelength-dispersed type X-ray spectroscope, based on the stored value. A counted ratio (f) and a counted time T at this time are multiplied. Thus, Bw= Be'fT, which is a background measured value converted by the wavelength-dispersed type X-ray spectroscope, is counted. By using the counted value N(lambdao), N(lambdao)-Be'fT is computed. The result is the peak strength excluding the background component at the wavelength lambdao.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention involves irradiating a sample with an electron beam, and at the time, emitting electron beams from the sample. Related to equipment for analyzing samples.

[Prior art] X-ray analyzer such as X-ray microanalyzer -C
When the sample is exposed to heat, the electron beam is irradiated onto a minute area of the sample.
The generated X-rays are spectrally analyzed to obtain the CX-ray spectrum. Such an X-ray analyzer has excellent wavelength resolution and wavelength-dispersive type -1-energy (I7 instrument), which has poor wavelength resolution, but mechanically moves the spectroscopic crystal] energy (
An energy dispersive X-ray spectrometer that can perform spectroscopy without
Using this X-ray spectrometer, we can detect the α-ray peak of mineral (Fe), as shown in Figure 1, by removing the background component. ) Strong α
I'm sure. In other words, this! If the peak wavelength of α-rays is one λ0, then l <:l'l 4). First, the position where only the X-rays having the wavelength λ0 are selectively guided to the X-ray detector is determined. The intensity W(
λ0) and the wavelength λ0+Δ of both tails of the peak.
The spectroscopic crystal was sequentially moved to the position for IR measurement of λ and λ0-Δλ, and the wavelengths λ0+Δλ and λ0-Δλ were measured.
Find the intensities W(λ0−Δλ) and W(λ0−Δλ) at , and then calculate from W(λ0) to 20 (BWcλ, which is the secret value of the background)−J, w<enter. +4 included) 10 vJ (>--4
χ))/2 ・<1> is subtracted. Part 1: In the past, the movement of the spectroscopic crystal was
If the measurement was repeated several times at each position, it was not possible to measure the pea intensity excluding the background component at a certain wavelength, which was complicated and time consuming.

[Object of the Invention] An object of the present invention is to solve the drawbacks of the conventional apparatus and to provide an apparatus capable of removing background components and measuring peak intensity in a short time.

[Structure of the Invention] The present invention provides a means for irradiating a sample with an electron beam, and a method for selecting only a specific wavelength component of X-rays emitted from a sample by irradiating the sample with an electron beam. The spectroscopy of ■、crystal、
A wavelength dispersive X-ray analyzer consists of an X-ray detector for detecting the X-rays emitted through the spectroscopic crystal, and a wavelength-dispersive X-ray analyzer that Separately, the energy required for counting 1) is added to a device equipped with an X-ray spectrometer. Multiply the b1 number of the energy-dispersive X-ray spectrometer by a certain ratio (Ii5). It is characterized by

[Example] Embodiments of the present invention will be described below with reference to the drawings.

. In FIG. 1 showing an embodiment of the present invention, 1 is a housing of an X-ray analyzer, and an electron gun 2 is disposed inside this housing 1. As shown in FIG. The electron beam 3 from the electron gun 2 is narrowed down by lenses 4 and 5 (the sample is irradiated).Although not shown in the figure, an electron beam deflection means is disposed within the housing 1.
It is possible to arbitrarily select the black position where the electron beam 3 falls on the sample 6 soil. Reference numeral 7 denotes a spectroscopic crystal for selecting a specific wavelength of xtM generated from the sample 6 by irradiating the sample 6 with the electron beam 2 and guiding it to the X-ray detector 8. This X-ray detector 8 detects I
[After the detection pulse is amplified by the amplifier 9, it is supplied to the counting circuit 10, where it is counted for the time set by the timer 11].

The count signal from this counting circuit 10 is supplied to an electronic computer 12. 13 is a display device C for numerically displaying the intensity of the spectral peak and displaying the spectral waveform.
be. 14 is a semiconductor detector for detecting X-rays generated from the sample 6.

16 is a cooling rod for cooling the semiconductor detector 14, and 15 is a cooling rod 4 for supplying refrigerant for cooling the cooling rod 16.
It's a 7-a-day game. This semiconductor detector 14 is required
Generates a pulse with a peak value that corresponds to the energy of the line.

This detection pulse is supplied to a multichannel pulse height analyzer 18 via an amplifier 17. This multi-channel pulse height analyzer 18 discriminates the output pulses of the semiconductor detector 14 according to the wave 1lLl values and calculates the output pulses from 1 to 1.
'If jl corresponding to each energy region of the memory
,! ! (J, store values of 1 to 1 for each −1 energy region. In this multi-channel pulse height analyzer 18, t;
4. To specify the measurement time from L, iW+, No. 11. :1. q is 11 (supplied).The output η of the multichannel pulse height analyzer 18 is calculated by the electronic calculation 1
2 can be supplied.

In such a configuration, the magnifying glass crystal 7 has a wavelength of λ0.
+Δλ measurement position, XI! The detection intensity W (20 + Δλ) at the wavelength λ0 + Δλ is obtained by calculating the wavelength λ0 + Δλ, and the signal corresponding to this W (λO−1Δλ) (J is supplied to the electronic calculator 12.i) (!j: Measurement of wavelength λ0-Δλ with spectroscopic crystal 7 1)'/Move to buy, wavelength λ0-Δ
Find the intensity W (λ0-△λ) that J hubs on λ and express this intensity C1! I (electronically fit the P issue 'g+Il Homare 12 (
This is supplied. Therefore, in the electronic computer 12,
[Expression (1) (J) Express the background Bw determined by the wavelength dispersive X-ray spectrometer, enter the value, and store this value in the memory. At the same time, the output horn pulses from the semiconductor detector 14 are supplied to the multi-de-sinnel wave height analyzer 18, and the output pulses from the semiconductor detector 14 are sent to the input device 18 (each -1 energy region 1).
~Rir. This r remainder, the above-mentioned tie:, /-ii signals are supplied to the analyzer 18;
1 un 1 ~ is the above-mentioned error interval τ in the divisor circuit 10
There are 11 lines and 4. ,, the electronic 61 calculation 12 supplies the multi-channel wave height analyzer 18 with a 1'' control signal, and the wavelengths stored in the memory of this analyzer 18; the old values at Ao + Δλ and λ0 Δλ λ
0+Δλ) and ]:(λ0−Δλ) are read out and supplied to the electrons ii't I'';l4 and 12.

In the electronic calculation (12), the energy dispersive X-ray spectrometer C measured by the following formula 4 and the background 3e are calculated and stored in the memory in the h1 calculator.

B, (χ.) = EE (Enter. Dimensions Entry) Middle Exit (Enter. -6 Entries)
)/2 −< 2) Furthermore, electronic hi calculation 12 i
, k, Pack-Brown l' He previously memorized wavelength dispersion Jljj Extract Ejt-tei and store it in memory.

r - (8w, /3e) Measure the peak intensity excluding the background component of 1 υ・! 2 of iron) t-.

Move the spectroscopic crystal 74 to a position where it can be detected, and the X-rays of wavelength/IO can be detected by A pulse is a number of circuits'
In I/O, for example, time T is counted, and as a result, for example, counting candy N(λ0) is counted by the 31 number circuit '10. A signal representing this count ll&N<20) is supplied to the electronic calculator 1812 to calculate the memory size. Also 1.
At the same time, the semiconductor detector 14 sends the X-rays generated by the test F316 to the semiconductor detector 14. The detection pulse is also detected by the multi-channel wave height 4R unit 18, and is counted 81 times for each energy key range. . There, the electronic computer 12 supplies a control signal to the multi-channel pulse height analyzer 18, and the wavelength λ0+Δλ counted by the multi-channel pulse height analyzer 18 over time and stored in its memory is -C.
and λ0-Δλ () Signals representing the numerical values [ゝ(λ0+Δλ) and [(λ0-Δλ) are read out and supplied to the electronic computer 12.

In electronic training program 12, based on these values, the
2) Determine the background measurement value 3e' by the energy dispersive X-ray spectrometer expressed by the formula, and add the value of f stored in advance to this determined measurement value Be' and the counting time period at this time. By multiplying these values together, a value 3w = 3e' f is calculated by converting this background measurement value into a background measurement value by a wavelength dispersive X-ray spectrometer.

Furthermore, in the electronic computer 12, if N (2c) -Be' f T- (4) is calculated using the calculated count value N(λ0) first, the background component at the desired wavelength λ0 is removed. is the peak intensity.

Therefore, when the computer 12 supplies a signal representing the obtained R field to the display device 13, the peak intensity of alpha rays is displayed on the display device 13, excluding the back brown 1~. Ru.

Note that the above-described embodiment is only one embodiment of the present invention, and many other embodiments may be adopted in actual use.

For example, in the above-mentioned embodiment, 8) Multiplication is performed to convert the background measured value obtained by the energy dispersive X-ray spectrometer into the wavelength dispersion by converting the constant value of 1j background in the X-ray spectrometer. In addition, we have attempted to execute the subtraction of equation (4) on an electronic computer, but these operations can also be implemented in hardware by using an arithmetic circuit or a subtraction circuit. can.

In addition, in the above embodiment, when determining the magnitude of the background component, the intensity at the base of the peak was measured and the average value was determined. It can also be implemented simply.

Furthermore, in the above-mentioned embodiment, only the conversion coefficient r for the background measurement of the α-ray peak of the button was measured and stored in advance, but for the β-ray peak of iron. The present invention can also be used when measuring the strong electric current of these peaks excluding the background components by measuring and storing in advance conversion factors for background measurements of peaks of other elements. The same applies.

[Effect] As is clear from the above explanation, according to the present invention, -
If you measure the crowding of background components using the Yoshi wavelength dispersive The intensity can be measured easily and in a short time.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the prior art, and FIG. 2 is a diagram for showing an embodiment of the present invention. 1: Housing, 2: Electron gun, 3: Electron beam, 4, 5: Lens,
6: Sample, 7: Spectroscopic crystal, 8: X-ray detector, 9.17:
Amplifier, ' 10: 4 number 1jjl path, 11: Timer, 12: 1 electronic meter, 13: Display [, 14: Semiconductor detector, 15: Decore, 16: Cooling rod, 18: Maru (-
fv channel wave 16 analyzer. Patent Applicant 1-1 Kiden Ryo Co., Ltd. Representative I11) - Husband

Claims (1)

[Claims] means for irradiating a sample with an electron beam; a spectroscopic crystal for selecting only a specific wavelength component of the X-rays generated from the sample 1 by irradiating the sample 1 with the electron beam; A wavelength-dispersive X-ray analyzer consisting of an X-ray detector for detecting the X-rays guided through the spectroscopic crystal, and 5R:/:'f from the sample.
In order to distinguish and count the radioactive X-rays according to their energies, an apparatus equipped with an energy dispersive X-ray spectrometer
13, near the wavelength selected by the spectrometer (bj
Means for subtracting a value obtained by multiplying the count value of the energy dispersive X-ray spectrometer by a fixed ratio from the count value of the detected pulses of the X-ray detector is provided. An X-ray analyzer that is characterized by its unique characteristics.