JPS62240846A - Calibration for fluorescent x-ray measuring apparatus - Google Patents

Abstract

PURPOSE:To enable simultaneously calibrations with multiple energies while permitting accurate calibration in a wide energy range, by using a fluorescent X-ray with not only one kind of energy but also multiple energies as such for calibration. CONSTITUTION:An excited radiation 2 radiated from a radiation source 1 is made to irradiate a sample 3 for calibration. A multi-energy fluorescent X-ray 4 generated from the sample 3 is detected with an X-ray detector 5 to be converted into an electrical signal, which is electrically amplified with a preamplifier 6 and a near amplifier 7. The electrical signal thus amplified is counted by the energies of the fluorescent X-ray with a multichannel analyzer 8 and sent to a CPU unit 9 as data of intensities of X-rays divided into channels. The unit 9 determines the number of channels in the fluorescence X-rays and intensities of X-rays categorized by energy and compares the results with a reference value predetermined for each category of energy to decide a correction value energy-wise.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to energy dispersive fluorescence X11 measurement in general.

(Summary of the invention) The present invention provides energy fractional fluorescent X-ray measurement @ directly.
Using a calibration sample that generates two or more types of fluorescent X-rays with different energies, calculate the number of channels and X# for each fluorescence X$2 of each energy! By correcting the intensity, it is possible to accurately calibrate the fluorescent X-ray measuring device in a wide energy range.

(Prior art) Calibration of a fluorescence X1g measuring device focuses only on fluorescent X-rays of one type of energy generated from a calibration sample, and corrects the number of channels and X-ray intensity of the focused fluorescence xIa. For XS of other energies, the correction amount is that
The number of channels has been corrected on the basis that it is proportional to the energy of the X-ray, or the X-ray intensity has been corrected on the basis that the intensity ratio with the standard value is unrelated to the energy of the X-ray.

(Problem to be solved by the invention) Fluorescence XIQ for calibration focuses only on the energy of panicles, and for fluorescent X-rays with other energies, the channel correction amount is based on the energy of the fluorescence xI2. If calibration is performed in the entire energy range based on the assumption that the intensity ratio is proportional or that the intensity ratio with the standard value is unrelated to the energy of the fluorescent X-ray, when these assumptions do not hold, for example When the channel correction amount is not proportional to the energy of the fluorescent X-ray and there is a bend or offset, or when the intensity ratio with the standard value is affected by the energy of the fluorescent X-ray, the true There is a problem in that there is a large difference between what should be corrected and what is actually corrected.

(Means for Solving the Problems) In order to solve the above problems, instead of using only one type of energy as a fluorescent X-ray for calibration, we used fluorescent XI of multiple energies! Calibration is performed at multiple energies simultaneously by using il and measuring them simultaneously with a multichannel analyzer. Furthermore, by interpolating correction values between each energy, corrections are applied to fluorescent X-rays of energies not used for calibration, which are close to the time when they should really be corrected.

(Embodiments) Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of the present invention. In the diagram? 1@1 is a radiation Ia source, from which excitation radiation 2 is irradiated onto a calibration sample 3. Although not shown in this figure, there is a device (such as a collimator) for converging the radiation ts11 or a device for attenuating and dazzling the radiation rA12 between the radiation source 1 and the calibration sample 3. - There is no problem even if there is intervention. In addition, the position of the calibration sample is similar to that of general samples to be measured, so that even if it is placed on a sample stage, excitation radiation is blocked for automatic calibration as described in Japanese Patent Publication No. 58-184655. Even if it is attached to a part of the shutter for the calibration sample, it can be installed anywhere as long as the fluorescent X-rays from the calibration sample can be introduced into the X-ray detector. Fluorescent X-rays 4 of multiple energies generated from the calibration sample 3 are detected by the x19 detector 5 and converted into electrical signals. The converted electrical signal is electrically amplified by a preamplifier 6 and a linear amplifier 7. The amplified electrical signal is counted by the energy of fluorescence
Sent to 誼9. The CPU device 9 emits fluorescence X of each energy.
The number of ray channels and the X-ray intensity are determined and compared with standard values determined for each energy to determine the supplementary Effl for each energy.

FIG. 2 shows a comparison example between the amount of correction according to the conventional method and the amount of correction according to the present invention. FIG. 2 shows 2Qch, 56ch, as a calibration sample for the present invention.

This is an example in which a device that generates fluorescence XS of four types of energy, 95ch and 110ch, is used.

(Effects) When calibrating a fluorescence . Furthermore, by interpolating the correction value between each energy, the fluorescence
Regarding i1 as well, since it is possible to apply a correction amount close to the amount that should really be corrected, there is an effect that accurate calibration can be performed in a wide energy range.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention. Figure 2 is a comparison diagram between correction by the conventional method and correction by the calibration method of the present invention. 1... Radiation source 2... Excitation radiation 3... Calibration sample 4... Fluorescent X-ray 5... X-ray detector 6... Preamplifier 7... Linear amplifier 8... Multi Channel analyzer 9... CPIJ device Large 24-column professional of the present invention 1.77 Figure 1

Claims (1)

[Claims] A radiation source for generating radiation that excites a sample; an X-ray detector for detecting fluorescent X-rays from the sample excited by the radiation; Multi-channel analyzer for discrimination and X of each discriminated channel
A calibration sample that generates two or more types of fluorescent X-rays with different energies by being excited by radiation in a fluorescent X-ray measuring device equipped with a CPU device that can compare and convert ray intensities. After detecting and discriminating the fluorescent X-rays from the calibration sample using The number of channels and X-ray intensity of each energy are compared with predetermined standard values, and the discrepancies between them are corrected using the CPU device for each fluorescent X-ray of each energy. energy value, its number of channels and
A method for calibrating a fluorescent X-ray measuring device, characterized in that the fluorescent X-ray measuring device can be calibrated accurately in a wide energy range even when the deviation of the line intensity from a standard value is not in a linear relationship.