JPH02304400A - X-ray spectroscopic device - Google Patents

Abstract

PURPOSE:To eliminate the need for repeating wavelength matching and intensity checking again after the start of a measurement and to allow measurement with high accuracy by previously irradiating a crystal for X-ray spectroscopy with X-rays. CONSTITUTION:An X-ray detector D is connected in mechanism to a spectral crystal C in such a manner that a slit for spectroscopy placed in front thereof is positioned always on the circumference of the specified radius running the point of a sample S to be irradiated with an electron beam and the center of the spectral crystal C. Wavelength scanning is executed by moving the spectral crystal C along a guide 1 by a feed screw. An X-ray source G is fixed to an arm 3 and the positional relation of the spectral crystal C and the X-ray source G is always constant. Namely, the prior irradiation of the crystal for X-ray spectroscopy of this X-ray spectroscopic device with the X-rays prior to the measurement is possible and, therefore, the need for frequent rematching the wavelength of the spectroscope until the change in the spectral crystal settles is eliminated and the measurement with the high accuracy is possible.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an X-ray spectrometer using a spectroscopic crystal.

(Prior Art) Conventionally, an X-ray spectrometer using a spectroscopic crystal has been used in such a way that the spectroscopic crystal is irradiated with X-rays only when in use. However, when a spectroscopic crystal is exposed to X&'it irradiation, the lattice spacing and reflected X-ray intensity change and gradually approach a constant value. Therefore, after starting the measurement, until the changes in the spectroscopic crystal settle down, it is necessary to frequently readjust the spectrometer's waveform and check the X-ray detection sensitivity, which is very troublesome and requires high accuracy. It was difficult to make measurements.

(Problem to be solved by the invention) This is an attempt to enable an X-ray spectrometer using a spectroscopic crystal to perform measurements in a stable state immediately from the start of each measurement (Means for solving the problem) In the ray spectrometer, the crystal for X-ray spectroscopy was constantly irradiated with X-rays.

(Function) As described above, the cause of the instability of an X-ray spectrometer using a spectroscopic crystal is that the lattice spacing of the spectroscopic crystal gradually changes when the spectroscopic crystal is irradiated with X-rays. Therefore, if the spectroscopic crystal is irradiated with X-rays in advance to change the spectroscopic crystal to the final state, measurement can be started immediately in a stable state. When X-ray irradiation is interrupted, the spectroscopic crystal returns to its original state, but the
Once irradiated with X-rays, the spectroscopic crystal has settled into a stable state due to the X-ray irradiation, so measurements can be taken at any time.

(Example) An example of the present invention is shown in the drawings. This embodiment is an example in which the present invention is applied to an X-ray microanalyzer. In the figure, e indicates an electron beam focused on the sample surface. C is a spectroscopic crystal that moves along a fixed straight line passing through the electron beam irradiation point on the sample surface. D is an X-ray detector, which is integrated with a spectroscopy slit Ds placed in front of it, and this slit! is mechanically connected to the spectroscopic crystal C so that it is always located on the circumference of a constant radius (one co-land circle) passing through the electron beam irradiation point of the sample S and the center of the spectroscopic crystal C. G is an X-ray source mounted on the above mechanism, and irradiates the spectroscopic crystal C with soft X-rays.

In this embodiment, the above-mentioned mechanism includes a spectroscopic crystal guide 1 fixed along a straight line, a spectroscopic crystal stand 2 that slides along this guide, and an arm 3 integrally extended from the stand 2. An arm 4 that is also rotatable with respect to the base 2, a guide 1 and an arm 4
The X! l! i1 detector and slit Ds
The integrated body can slide on the arm 4, and the length of the arm 3 and the link 8 is equal to the radius of the Roland circle, and the connecting pin p of the link 6.7 is inserted into the sliding groove of the arm 3. By sliding it inward, the center normal of the spectroscopic crystal C is always directed toward the center of the Rowland circle. With this configuration, wavelength scanning is performed by moving the spectroscopic crystal C along the guide 1 using the feed screw. Since the X-ray source G is fixed to the arm 3, its positional relationship with the spectroscopic crystal C is always constant. And the X-ray source G is from above the center line of arm 3 or from the center line of arm 4.
It is installed off to the side closest to the By doing so, even if the X-rays emitted from the X-ray source G are reflected by the spectroscopic crystal, they are reflected to the side opposite to the detector, so that background rise during measurement can be suppressed to a low level. X-ray source G
The X-rays emitted from the X-rays are selected to have longer wavelengths than the wavelength range of X-rays in actual X-ray spectrometry. By using a detector with an energy analysis function such as a proportional counter for the X-ray detector, the background increase due to the X-rays emitted from the X-ray source G can be further reduced (suppressed) during measurement. The operation of the X-ray source G may be stopped.

(Effects of the Invention) According to the present invention, the spectroscopic crystal has already been irradiated with X-rays before measurement and changes are stable, so there is no need to repeat wavelength alignment and intensity confirmation after the start of measurement. Measurement operations are simple and efficient, and the spectroscopic crystal is stable, allowing highly accurate measurements.

[Brief explanation of the drawing]

The drawing is a side view of an apparatus according to an embodiment of the present invention. e...electronic beam, S...sample, C...spectroscopy crystal, D...X-ray detector, Ds...spectroscopy slit,
G...X-ray source. Agent: Patent Attorney Hiroshi Agata Fixed 1 line

Claims (1)

[Claims] An X-ray spectrometer characterized in that a crystal for X-ray spectroscopy is irradiated with X-rays before measurement.