JPH06160313A - Fluorescent x-ray analysis - Google Patents

Abstract

PURPOSE:To provide an fluorescent X-ray analysis method which facilitates the correction of errors attributed to radioactivity of a sample itself in a simultaneous type fluorescent X-ray analyzer. CONSTITUTION:An X-ray shutter 7 free to open or close is provided on the front of a radiation window 6 of an X-ray tube 5 and a sample 3 is set facing the X-ray tube radiation window 6 through the X-ray shutter 7. With the shutter closed, a first output of the X-ray tube detector 11 is measured and with the shutter opened, a second output thereof 11 is measured. The first output is subtracted from the second output to correct measuring errors attributed to radioactivity the sample 3 has.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent X-ray analysis method in which a dispersive crystal is fixed.

[0002]

2. Description of the Related Art When detecting various metals or their ions contained in cooling water of a nuclear reactor, fluorescent X-ray analysis is carried out using a filter obtained by filtering the cooling water as a sample. But,
Such a sample may itself have radioactivity, and in this case, fluorescent X-rays generated by irradiation of X-rays and X-rays generated by the radioactivity of the sample itself are simultaneously detected. That is, X-rays due to the radioactivity of the sample itself may be included as the background of the fluorescent X-rays to be detected. In a scanning or energy dispersive X-ray fluorescence analyzer, the radioactivity of a sample is detected by setting the scanning angle of the X-ray detector or the pulse wave height to be detected to a value slightly displaced from a predetermined value. You can add a correction.

[0003]

However, in the simultaneous X-ray fluorescence analyzer in which the dispersive crystal is fixed, the measurement error due to the radioactivity of the sample itself cannot be easily corrected by such means. Therefore, the present invention
It is intended to provide a fluorescent X-ray analysis method capable of easily correcting an error due to the radioactivity of the sample itself in the simultaneous fluorescent X-ray analysis apparatus.

[0004]

This invention intends to detect X-rays of a specific wavelength, that is, to detect X-rays of various wavelengths generated from the sample, by disposing a dispersive crystal on the sample. The spectroscopic crystal and the detector are preliminarily set at predetermined positions so that only the characteristic X-ray of the substance to be diffracted is generated, and the characteristic X-ray is detected by an appropriate X-ray detector opposite to the spectroscopic crystal. In the fixed simultaneous X-ray fluorescence analyzer,
X for irradiating the sample with a primary X-ray to excite the sample
An openable and closable X-ray shutter is provided on the front surface of the X-ray emission window of the X-ray tube. Using this simultaneous X-ray fluorescence analyzer,
When the first output of the X-ray detector is observed with the shutter closed, the output based on the radiation can be known when the sample has radioactivity. Therefore, by opening the shutter and exciting any sample with X-rays,
Before and after the characteristic X-ray intensity of the desired substance contained in the sample is detected via the dispersive crystal, the shutter is closed once as described above, and the first output of the detector is observed. By subtracting the output from the measured value, the measurement error due to the radioactivity of the sample itself is corrected. As described above, the present invention has the action and effect of being able to correct the measurement error based on the radioactivity of the sample itself with a simple device.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view of this embodiment, and FIG. 2 is a cross-sectional view taken along the line A-A. A turntable 2 is provided in a vacuum chamber 1 on which a plurality of plate-shaped or sheet-shaped samples 3 are placed. It is supposed to be placed. A sample insertion / extraction port 4 is provided so as to face a part of the table 2, and an X-ray emission window 6 of an X-ray tube 5 attached to an airtight wall of the vacuum chamber 1 is provided as one of the samples 3 on the table 2. Further, an X-ray shutter 7 is provided in front of the window 6 so as to face the window. The shutter 7 is driven by an electric motor 8 to open and close the window 6 of the X-ray tube as shown by a solid line and a chain line in FIG. On the side of the sample 3 facing the X-ray tube 5, a plurality of slits 9 and a dispersive crystal 10, X are fixed.
A line detector 11 and a slit 12 on the front surface thereof are provided. In this embodiment, the plurality of samples 3 can be stored in the vacuum chamber 1. However, in the present invention, one sample 3 may be stored in the vacuum chamber 1.

In the above-mentioned apparatus, first, the first output of each X-ray detector 11 is read with the shutter 7 closed, and this is recorded. Next, the shutter 7 is opened like a chain line and one of the samples 3 is irradiated with X-rays, and the second output of each detector 11 at that time is read. By subtracting the recorded first output from the second output, the value of the substance determined by the lattice plane spacing of each dispersive crystal and its arrangement angle can be accurately known.

[0007]

As described above, according to the present invention, the error when the sample has radioactivity is corrected by the simple structure in which the window of the X-ray tube is provided with the openable shutter. be able to.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

[Explanation of symbols]

3 ... Sample, 5 ... X-ray tube, 6 ... X-ray tube radiation window, 7 ... Shutter, 10 ... Spectroscopic crystal, 11 ... X-ray detector.

Claims (1)

[Claims] 1. An X-ray shutter that can be opened and closed is provided in front of an X-ray emission window of an X-ray tube, and a sample is opposed to the window of the X-ray tube through the shutter, and a fixed spectroscopic crystal is fixed on the sample. And a simultaneous X-ray fluorescence analyzer equipped with an X-ray detector so that X-rays generated from the sample and diffracted by the dispersive crystal are incident on the X-ray analyzer with the shutter closed. The first output of the line detector is measured, while the X-axis is measured with the shutter open.
Fluorescent X characterized in that the measurement error due to the radioactivity of the sample is corrected by measuring the second output of the line detector and subtracting the first output from the second output.
Line analysis method.