JPH0773831A - X-ray device - Google Patents

Abstract

PURPOSE:To make the measurement using X-ray having different energy simply and at a low cost. CONSTITUTION:A rotary anode 11 is divided into a plurality of regions 111, 112 about the circumference. and the regions are made from different substances (target substance), for example copper and chromium. A rotary encoder 13 is furnished to sense the rotational angle of this rotary anode 11, and a gate circuit 19 is controlled in accordance with the rotational angle, and the result from X-ray sensing is taken in according to the region on the rotary anode 11, i.e., the target substance constituting the region.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various X-ray devices utilizing characteristic X-rays such as an X-ray diffractometer and an X-ray photoelectron spectroscopy (XPS) device, and more particularly to an X-ray generator having a rotating anode and an X-ray generator. The present invention relates to an X-ray device having a line detecting means.

[0002]

2. Description of the Related Art There are various types of X-ray devices that utilize characteristic X-rays. As an example of such an X-ray apparatus, the configuration of a conventional X-ray diffraction apparatus is shown in FIG. This X-ray diffractometer includes an X-ray generator including a target 51 and a filament 52, a goniometer 55 in which a sample 54 is placed, and a slit 53 provided between the X-ray generator and the goniometer 55 to narrow down the X-rays. A proportional coefficient tube 56 attached to the goniometer 55, an amplifier 57 for amplifying the output of the proportional coefficient tube 56, and a recording device 58 provided on the output side of the amplifier 57. A high voltage of about several tens kV is applied between the target 51 and the filament 52, the target 51 is irradiated with the accelerated electron beam from the filament 52, and the atoms on the surface of the target 51 are excited, thereby Unique characteristic X-rays are generated. At the same time, continuous X-rays are also generated by bremsstrahlung when the electron beam hits the target 51. FIG. 4 shows an X-ray spectrum when a single element is used as the target substance. At this time, most of the energy of the electron beam becomes heat and heats the target 51. Therefore, in order to prevent damage to the target 51, cooling water is circulated inside the target 51, and the target 51 has a cylindrical shape. As a result, the electron beam is rotated at high speed around the axis of rotation (rotary anode) so that the heat load of the electron beam is not concentrated in one place.

[0003]

The optimum X-ray energy for measurement on various samples differs depending on the sample and the measurement method. However, an X-ray tube using only a single element as a target material produces only characteristic X-rays with a single energy. For this reason, when measuring with X-rays of different energies, the target must be replaced each time. Since the target is placed in a vacuum and a cooling water pipe or the like is connected, replacement of the target requires a great deal of labor and time.

If a rotary anode using a plurality of elements as a target material is used, characteristic X-rays having different energies are simultaneously generated. FIG. 5 shows an X-ray spectrum when a plurality of elements are used as target substances.
However, the fluorescence counter and the proportional counter, which are widely used for the detection of X-rays, do not have high energy resolution, so that X-rays of different energies cannot be completely separated. Therefore, a signal from a phenomenon due to X-rays other than the X-ray of the energy of interest is mixed, and the measurement accuracy decreases. FIG. 6 shows the wave height distribution when the X-ray of the spectrum is detected by the proportional counter in FIG. Si (L
If a semiconductor detector such as i) is used, the energy resolution is high, so that different X-rays can be separated. However, the semiconductor detector needs to be cooled by liquid nitrogen, so that maintenance is complicated and the device becomes large and expensive.

It is an object of the present invention to provide an X-ray device which enables simple and inexpensive measurement using X-rays of different energies.

[0006]

The X-ray apparatus of the present invention has a rotation angle detecting means for detecting the rotation angle of the rotary anode, and the rotary anode is composed of different target materials in the circumferential direction.

[0007]

The characteristic X-rays having different energy in time series are generated from the rotating anode composed of different target materials in the circumferential direction. Therefore, the output of the X-ray detection means also corresponds to the characteristic X-ray of each energy in time series. Here, since the rotation angle detecting means for detecting the rotation angle of the rotating anode is provided, the output of the X-ray detecting means is fetched in synchronization with the output from the rotation angle detecting means, so that for each specific X-ray energy. The detection value can be acquired. That is, the measured value for each energy can be obtained.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an X-ray apparatus according to an embodiment of the present invention.

This X-ray apparatus is used for measurement of X-ray diffraction, and includes an X-ray generator 10, a goniometer 16 on which a sample 15 is placed, and between the X-ray generator 10 and the goniometer 16. Slit 14 for narrowing X-rays
And a proportional counter 17 attached to the goniometer 16.
And an amplifier 18 for amplifying the output of the proportional counter 17, a gate circuit 19 provided on the output side of the amplifier 18, and a recording device 20 provided on the output side of the gate circuit 19. The X-ray generator 10 includes a rotating anode 11
And a filament encoder 12 and a rotary encoder 13. Here, the rotating anode 11 has a cylindrical shape, and the surface of a half region 11 ₁ of the entire circumference in the circumferential direction is made of copper (Cu), and the surface of the other half region 11 ₂ is chromium (Cr). It is composed of. The rotary encoder 13 is an electromagnetic type encoder connected to the rotary shaft of the rotary anode 11 and generates a positive or negative signal according to the rotation angle of the rotary anode 11. Specifically, a positive signal is generated when the rotation angle is such that the electron beam from the filament 12 is irradiated to the region 11 ₁ made of Cu of the rotary anode 11, and the electron beam is similarly made to the region 11 ₂ made of Cr. A negative signal is generated when the rotation angle is such that is emitted.
The gate circuit 19 outputs the signal from the amplifier 18 to the recording device 20 according to whether the signal from the rotary encoder 13 is positive or negative.
It is configured to transmit and shut off. Whether to transmit the signal when the signal is positive or negative can be appropriately set externally.

Next, the operation of this embodiment will be described.

While rotating the rotating anode 11, the rotating anode 1
By applying a high voltage between 1 and the filament 12, the rotating anode 11 is irradiated with the electron beam from the filament 12, and the characteristic X-ray is generated from the rotating anode 11. Since the half circumference of the rotary anode 11 is made of Cu and the remaining half circumference is made of Cr, characteristic X-rays of Cu are generated in half of one rotation of the rotary anode 11, and the characteristic X-rays of Cr are generated in the remaining time. Characteristic X-rays will be generated.

The X-rays 21 generated by the rotating anode 11 are finely collimated by the slit 14 and enter the sample 15. The X-ray diffracted by the sample 15 enters the proportional counter 17. In the proportional counter 17, a pulse having a wave height proportional to the energy of the incident X-ray photon is obtained. This pulse is amplified by the amplifier 18 and then input to the recording device 20 via the gate circuit 19. The recording device 20 counts the number of pulses and records as the intensity of X-rays.

In this embodiment, a gate circuit 19 controlled by the output of the rotary encoder 13 is provided, and the gate circuit 19 is set to open (pass a pulse) when the output of the rotary encoder 13 is positive. If so, X-ray pulses are counted only during the period when the characteristic X-ray of Cu is generated from the rotating anode 11. Similarly, when the gate circuit 19 is set to open when the output of the rotary encoder 13 is negative, the X-ray pulses are counted only during the period when the characteristic X-ray of Cr is generated. . Therefore, the measurement can be performed by switching the characteristic X-rays of Cu and Cr simply by changing the setting of the gate circuit 19. Therefore, the X-ray having the optimum energy for the sample can be immediately switched to the measurement without exchanging the target or the tube, and the measurement can be efficiently performed. Here, 2
I explained the rotating anode that combines two substances,
It is also possible to use a rotating anode in which a large number of substances are combined.

Next, another embodiment of the present invention will be described. FIG. 2 is a block diagram showing the configuration of an X-ray apparatus according to another embodiment of the present invention.

This X-ray apparatus is used for measuring the X-ray photoelectron spectrum, and the X-ray generator 30, the moving stage 36 on which the sample 35 is placed, the X-ray generator 30, and the moving stage 36. And a slit 34 for narrowing X-rays, an electron energy analyzer 37 for detecting the energy of the photoelectrons 42 from the sample 35, and an A / D converter for converting the output value of the electron energy analyzer 37 into a digital value. 38 and a memory 40 composed of 6 blocks 40 ₁ to 40 _6.
And a switching circuit 39 provided between the output of the A / D converter 38 and the memory 40. The X-ray generator 30 is composed of a rotary anode 31, a filament 32, and a rotary encoder 33. Here rotating anode 31 has a cylindrical shape, which is 6 equally divided in the circumferential direction, 6 equally divided respective areas 31 ₁ to 31 ₆ surface was, respectively, copper (Cu), nickel (Ni ), Chromium (Cr), titanium (Ti), cobalt (Co), and tungsten (W). Rotary encoder 3
Reference numeral 3 is an optical type connected to the rotary shaft of the rotary anode 31, and is configured to output a signal corresponding to the rotation angle of the rotary anode 31.

The memory 40 has 1000 blocks per block.
It has a channel capacity and stores numerical data for each channel, and functions as a multi-channel analyzer when combined with the A / D converter 38. That is, each block 40 ₁ to 40 of the memory 40
₆ is used for storing the spectrum data of 1000 channel width. The switching circuit 39 is controlled by the output of the rotary encoder 33 and transfers the output of the A / D converter 38 to any block of the memory 40 in accordance with the rotation angle of the rotary anode 31.

Next, the operation of this embodiment will be described.

While rotating the rotating anode 31, the rotating anode 3
By applying a high voltage between 1 and the filament 32, characteristic X-rays are generated from the rotating anode 31. Since the rotating anode 31 is composed of six kinds of target materials, Cu, Ni, Cr, and
The characteristic X-rays of Ti, Co, and W are sequentially generated. The X-ray 41 generated by the rotating anode 31 is finely collimated by the slit 34 and enters the sample 35. Sample 35
The photoelectrons 42 generated in 1 are incident on the electron energy analyzer 37, and the energy is measured.

The output of the electron energy analyzer 37 is A /
The D converter 38 converts the data into numerical data of 1000 channels. Then, this numerical data is sent to the switching circuit 3
9, the signal is input to any block of the memory 40 according to the signal from the rotary encoder 33, and as a result,
The data of the corresponding channel of the block is incremented by 1. That is, the data when the characteristic X-ray of Cu is generated is stored in the first block 40 _1, and the data when the characteristic X-ray of Ni is generated is the second block 40 1.
₂ sets are stored in 6 blocks 40 ₁ to 4 4
The photoelectron spectrum data corresponding to the X-rays of different energies are stored in each of 0 ₆ . If the contents of any _{one of the} blocks 40 ₁ to 40 ₆ are read out after the series of measurements is completed, the X-ray measurement result of the energy of the characteristic corresponding thereto can be known.

In this embodiment, the sample can be irradiated with X-rays of various optimum energies at the same time without replacing the target, so that the measurement can be performed very efficiently.

[0021]

As described above, according to the present invention, the rotation angle detecting means for detecting the rotation angle of the rotating anode is provided, and the rotating anode is composed of different target materials in the circumferential direction, thereby exchanging the target. It is possible to perform measurement with characteristic X-rays of different energies without any effect, and there is an effect that measurement efficiency is achieved. Further, there is an effect that an inexpensive detector having low energy resolution can be used.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an X-ray apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of an X-ray apparatus according to another embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration example of a conventional X-ray device.

FIG. 4 is a graph showing an X-ray spectrum from a rotating anode using a single element as a target material.

FIG. 5 is a graph showing an X-ray spectrum from a rotating anode using a plurality of elements as a target material.

FIG. 6 is a graph showing a wave height distribution when X-rays showing the spectrum of FIG. 4 are measured by a proportional coefficient tube.

[Explanation of symbols]

 10,30 X-ray generator 11,31 Rotating anode 12,32 Filament 13,33 Rotary encoder 14,34 Slit 15,35 Sample 16 Goniometer 17 Proportional counter 18 Amplifier 19 Gate circuit 20 Recording device 21,41 X-ray 36 Moving Stage 37 Electronic energy analyzer 38 A / D converter 39 Switching circuit 40 Memory 42 Photoelectrons

Claims (3)

[Claims] 1. An X-ray apparatus comprising an X-ray generating means having a rotating anode and an X-ray detecting means, comprising rotation angle detecting means for detecting a rotation angle of the rotating anode, wherein the rotating anode has a circumference. An X-ray device characterized by being composed of target materials different in direction. 2. The X-ray apparatus according to claim 1, wherein the output of the X-ray detection means is taken in only when the rotation angle of the rotary anode is within a certain range. 3. The X-ray apparatus according to claim 1, further comprising a plurality of data areas, wherein the output of the X-ray detection means is captured in different data areas according to the rotation angle of the rotating anode.