JP5012128B2 - Detector for X-ray absorption analysis - Google Patents

Description

  The present invention relates to a detector for X-ray absorption analysis capable of measuring an X-ray absorption fine structure spectrum of a plurality of samples by an electron yield method or simultaneously measuring an X-ray absorption fine structure spectrum by an electron yield method and a transmission method.

  The X-ray absorption fine structure (XAFS) analysis method measures and analyzes a fine vibration structure appearing in an X-ray absorption spectrum of a target atom contained in a sample, thereby analyzing a local structure around the target atom, for example, an arrangement. It is an analytical method that can directly know the order and type of coordination atom, bond distance or bond target, and is widely used in the fields of semiconductor industry and chemical industry.

  FIG. 10 is a diagram showing an X-ray absorption spectrum, and shows an X-ray absorption spectrum near the K absorption edge of the Ni foil. Referring to FIG. 10, the vibration of the X-ray absorption coefficient is observed from the K absorption edge of Ni atoms to the high energy side. Among these, the vibration generated in the range of several tens of eV from the absorption edge includes information on the electronic state that changes depending on the valence and oxidation state of the target atom and the target property of the bond with the target atom. Further, the vibration generated in the range of several hundreds eV from the absorption edge includes information on the types of atoms arranged around the target atom, the distance to the atoms, and the coordination number. Therefore, by analyzing the X-ray absorption spectrum, it is possible to know in detail the coordination of the target atom and the electron bonding state.

  Generally, an electron yield method and a transmission method are widely used as measurement methods for X-ray absorption fine structure analysis. In the electron yield method, X-rays are incident on a sample surface, and an X-ray absorption spectrum is observed by measuring the amount of electrons, for example, Auger electrons, emitted from the sample surface by the photoelectric effect. According to this electron yield method, an X-ray absorption spectrum can be observed for an extremely shallow surface layer from which Auger electrons can escape, for example, a layer having a depth of several tens to several hundreds of nm.

  On the other hand, in the transmission method, the X-ray intensity incident on the thin sample and the X-ray intensity transmitted through the thin sample are measured, and the X-ray absorption amount and thus the X-ray absorption coefficient are calculated from the intensity ratio. By this transmission method, an X-ray absorption spectrum averaged in the thickness direction of the sample can be observed.

  Thus, the electron yield method observes the absorption spectrum on the sample surface, and the transmission method observes the average absorption spectrum inside the sample. In many cases, the structure of the bond between atoms differs between the inside and the surface of the sample. For this reason, in order to separate and observe the absorption spectrum of the inside and the surface of the sample, it is desired to apply the observation of the absorption spectrum by the transmission method and the electron yield method to the same sample.

  However, in order to carry out these two measurement methods, two measurements are required, and the measurement time becomes long. In addition, two measurements must be performed with different apparatuses or arrangements, and it is difficult to maintain the same measurement position of the sample.

  For this reason, the transmission method and the electron yield method are simultaneously performed by the same analyzer, thereby shortening the measurement time and maintaining the identity of the measurement position, or by simultaneously measuring multiple samples. An analyzer that can shorten the time is desired. However, it has been difficult for the conventional apparatus to simultaneously perform the electron yield method and the transmission method, or to simultaneously measure a plurality of samples, as will be described in detail below.

  FIG. 11 is a cross-sectional view of a conventional electron yield method measuring apparatus, and shows an outline of the configuration of an X-ray absorption fine structure analyzer using the conversion electron yield method.

  Referring to FIG. 11, the conventional electron yield measuring apparatus has a conductive chamber 120 whose inner wall is covered with an insulating layer 120 a, and a window 124 through which incident X-rays 101 pass is formed in front of the chamber 120. Is provided. The window 124 is made of an X-ray transmitting material and hermetically seals the inside of the chamber 120. A gas, for example, He flows into the chamber 120 from the gas inlet 126a and is discharged from the exhaust port 126b. The sample 122 is placed on the sample holder 121 so as to be inclined with respect to the window 124 in the chamber 120. Further, a charge collecting electrode 125 to which a negative voltage is applied from a power source 128 is provided above the sample 122 in the chamber 120. Further, a conductive wire 123 is connected to the sample 122, and the conductive wire 123 is connected to a current measuring instrument 127 placed outside the chamber 120.

When incident X-rays transmitted through the window 124 are irradiated onto the surface of the sample 122, Auger electrons emitted from the surface of the sample 122 collide with a gas (for example, He) in the chamber and ionize it, and ions (for example, He ^+). ) Is generated. Since Auger electrons usually have an energy of about several keV, several hundreds of Hes that require energy of about 30 eV to ionize are ionized. These ionized ions are attracted to the charge collecting electrode 125 to which a negative voltage of, for example, several hundred volts is applied, are accelerated, and further propagate while colliding with the gas in the chamber to generate a large number of ions. Then, the charge of these ions is absorbed by the charge collection electrode 125 and flows to the charge collection electrode 125 as an ionic current. That is, a current due to ions amplified by the amount of Auger electrons flows. As a result, an amplified current having a magnitude corresponding to the amount of Auger electrons emitted flows through the conductive wire 123 connected to the sample 122. By measuring this current with a current meter, the amount of Auger electrons emitted can be measured, and the amount of X-rays 101 absorbed by the sample 122 can be measured from the measured amount of Auger electrons emitted.

  In the conventional electron yield method measuring apparatus described above, the X-ray transmitted through the sample 122 is shielded by the sample holder 121. For this reason, this apparatus cannot be applied to the transmission method.

  FIG. 12 is a conceptual diagram of a conventional X-ray composite analyzer, which shows the arrangement of an X-ray composite analyzer that can realize X-ray absorption analysis by the transmission method and fluorescent X-ray analysis by the reflection method with the same device. Yes. FIG. 12A shows an arrangement when the transmission method is used, and FIG. 12B shows an arrangement when the reflection method is used.

  Referring to FIG. 12A, incident X-ray 101 a that has passed through the slit 134 and has a rectangular cross section passes through the transmission X-ray detector 131 and enters the sample 132 perpendicularly. The X-ray detector 131 measures the intensity of incident X-rays. The sample 132 is a thin film that can sufficiently transmit X-rays, for example, a Ni thin film, and is attached so as to close a through hole formed in the rotating disk-shaped sample holder 133. The sample holder 133 is held perpendicular to the incident X-ray 101a, and sequentially moves a plurality of samples 132 attached by rotation to a position where the incident X-ray 101a enters perpendicularly. The transmitted X-ray 101b that has passed through the sample 132 enters the X-ray detector 130 disposed rearward (to the right in the drawing), and the X-ray intensity is measured. Then, the X-ray absorption amount and further the X-ray absorption spectrum of the sample 132 are calculated from the intensity ratio between the incident X-ray 101a and the transmitted X-ray 101b.

  On the other hand, in the reflection method, with reference to FIG. 12B, a sample 132 having the same shape (no through hole is provided) as the sample holder 133 used in the transmission method described above is used. Then, the incident X-ray 101 a is incident on the surface of the sample 132, and the intensity of the fluorescent X-ray 135 emitted from the surface of the sample 132 is measured by the X-ray detector 130.

  Thus, in the transmission method, the sample and the sample holder are designed to transmit X-rays, whereas in the reflection method, the sample and the sample holder are not designed to transmit X-rays. For this reason, the sample holder used in the transmission method and the reflection method cannot be used in common. Therefore, it is difficult to perform the transmission method and the reflection method at the same time.

  FIG. 13 is a cross-sectional view of a conventional X-ray detector, showing the structure of a transmission-type detector used for measuring the X-ray intensity by the absorption method using the above-described conventional X-ray composite analyzer.

  Referring to FIG. 13, the container 110 of the X-ray detector 131 is formed by sealing a cylindrical barrel 111 and a front end 112 and a rear end 113 of the barrel 11. A gas such as Ar flows into the container 110 from the gas inlet 116 a near the front end 112 and is exhausted from the exhaust port 116 b near the rear end 113. A window 114 through which the X-ray 101 passes is provided at the front end 112 and the rear end 113 of the container 110. In addition, an X-ray intensity measuring electrode 115 a to which a negative voltage is applied is provided above the container 110, and an X-ray intensity measuring electrode 115 b that is grounded via a current measuring device 117 is provided below.

The X-ray 101 that has entered the container 110 from the window 114 at the front end 112 of the container 110 ionizes the gas (for example, Ar) in the container 101. The ionized gas ions and electrons are attracted to the X-ray intensity measuring electrodes 115a and 115b, and the current is measured by a current measuring instrument. Thus, the X-ray detector 131 functions as an ionization chamber, a proportional counter, or a Geiger counter.
JP 2000-11503 A JP 05-188019 A

  As described above, in the conventional X-ray absorption fine structure analyzer, since the sample holder is different between the transmission method and the electron yield method, X-ray absorption spectra by the transmission method and the electron yield method are simultaneously measured with the same device. It was difficult. For this reason, in order to observe the X-ray absorption spectrum by the transmission method and the electron yield method, two measurements (measurement by the transmission method and the electron yield method) are performed using different sample holders or different analyzers. There is a problem that the measurement time becomes long and it is difficult to guarantee the identity of the measurement position.

  Further, the measurement by the transmission method or the electron yield method cannot be performed on a plurality of samples at the same time. For this reason, the number of times of measurement is required as many as the number of samples, and there is a problem that the analysis time becomes long when measuring a large number of samples.

  The present invention is for X-ray absorption analysis capable of simultaneously measuring X-ray absorption fine structure spectra by an electron yield method and a transmission method, or simultaneously measuring X-ray absorption fine structure spectra of a plurality of samples. The object is to provide a detector.

  The detector for X-ray absorption analysis according to the first configuration of the present invention for solving the above-described problem is that other detection is performed by maintaining the airtightness between the inside of the detector container and the outside air at the front end of the detector container. A connecting portion connected to the rear end of the container. This connecting portion is provided with a through hole that can be airtightly closed by a sample or an X-ray transmitting material.

  Further, the detector for X-ray absorption analysis has an X-ray intensity measuring electrode that collects electric charges generated by X-rays that have entered the container through the through-hole. It functions as a conventional transmission detector used for measuring the line intensity.

  In the detector having the first configuration, different detectors can be connected to the front end and the rear end of the detector via the connection portion. The connecting portion seals the inside of the detector airtightly from the outside air, and the inside of the detector connected back and forth is communicated by a through hole provided in the connecting portion. The through hole can be airtightly closed using a sample or an X-ray transmitting material. Therefore, since the gas in the front and rear detectors is separated, the front and rear detectors can be operated independently of each other.

  In the configuration in which a plurality of detectors are connected in this way, the X-rays incident from the through hole of the detector located at the foremost end pass through the through hole of the subsequent detector or block the through hole. Since it passes through the X-ray transmissive material, it passes through the connected detectors. Therefore, the X-ray intensity located before and after each sample can be measured by closing one or a plurality of through holes with the sample. Further, the X-ray absorption spectrum of each sample is measured from the X-ray intensity before and after each sample. Therefore, the X-ray absorption spectrum for each sample of a plurality of samples can be measured simultaneously.

  The detector for X-ray absorption analysis according to the second configuration of the present invention is the detector for X-ray absorption analysis of the first configuration, instead of the X-ray intensity measurement electrode, in the through hole in the detector container. A charge collection electrode is provided in close proximity. The charge collection electrode is for collecting charges generated by electrons emitted from the sample, and a negative voltage, for example, is applied thereto. Further, the charge collection electrode is provided with a small hole through which the X-rays that have entered through the through-hole (or the sample or the X-ray transmitting material) pass.

  In addition, it has a current detector for measuring the current flowing through the sample. For this reason, the charge generated by the ionization of the gas by the electrons emitted from the sample is absorbed by the charge collection electrode arranged near the through hole (that is, near the sample) and corresponds to the amount of electrons emitted from the sample. Current flows through the sample and is detected by the current detector. Thus, the detector of the second configuration can be used as a measuring device having the function of the electron yield method.

  In the detector of the second configuration, the X-ray incident from the front and transmitted through the sample passes through the small hole of the charge collecting electrode, and further passes through the through hole of the rear end connection portion, thereby the rear end of the detector. Exits from. For this reason, by connecting a plurality of detectors of the second configuration and arranging the samples in the through holes of each detector, the current flowing through each sample is measured, and the X-ray absorption spectrum by the electron yield method is measured. be able to. Since this measurement is performed on all of the plurality of samples at the same time, the measurement time can be greatly shortened.

  In the measurement of the X-ray absorption spectrum by the electron yield method using the detector of the second configuration described above, the incident X-ray intensity is measured before the detector of the second configuration that functions as a detector of the electron yield method. It is preferable to arrange a detector of the first configuration that functions as a detector. Thereby, the absorption amount can be corrected by measuring the incident X-ray intensity incident on the sample. Furthermore, the detector of the first configuration can be arranged after the detector of the second configuration. Thereby, the transmitted X-ray intensity which permeate | transmitted the sample can be measured. Therefore, the X-ray absorption spectrum by the transmission method and the X-ray absorption spectrum by the electron yield method can be simultaneously observed.

  The detector for X-ray absorption analysis according to the third configuration of the present invention is a detector for collecting electric charge of the detector according to the second configuration, in addition to the detector according to the first configuration including the electrode for X-ray intensity measurement. And a current detector for measuring the current flowing through the sample.

  In the detector having the third configuration, either the X-ray intensity measuring electrode or the charge collecting electrode is selected and a voltage is applied. Thus, by selecting the electrode to which the voltage is applied, it can be made to function as a detector having any function of measuring the X-ray intensity or measuring the X-ray absorption amount by the electron yield method. Therefore, in the measurement using only one or both of the detectors of the first and second configurations described above, the detection unit of the analyzer can be configured by a kind of third configuration detector. Therefore, even when measurement is performed by changing the connection order of detectors having different functions, measurement can be easily performed only by selecting an electrode to which a voltage is applied, without reconfiguring the connection order of the connected detectors.

  The detector of the 4th structure of this invention isolate | separates the inside of a detector container into several division by a separation part along an X-ray passage axis. A through-hole through which X-rays that can be airtightly closed by a sample or an X-ray transmitting material are opened in the separation portion so that the X-rays are transmitted therethrough. Similarly to the third configuration, the X-ray intensity measurement electrode and the charge collection electrode are arranged in the compartment, and further, a current detection unit that measures the sample current is provided in the compartment.

  The detector of the fourth configuration forms a state in which a plurality of detectors of the third configuration are connected and fixed in an integrated detector container. Therefore, its function is the same as that of connecting a plurality of detectors of the third configuration. By integrally forming in this way, the structure of the detector can be strengthened.

  According to the present invention, the X-ray absorption fine structure can be measured by using a plurality of samples simultaneously or by using the transmission method and the electron yield method simultaneously, so that the X-ray absorption fine structure analysis can be performed quickly. .

  The first embodiment of the present invention relates to an X-ray absorption analysis detector provided with an X-ray intensity measurement electrode and a charge collection electrode.

  FIG. 1 is a cross-sectional view of a detector according to a first embodiment of the present invention, showing the internal structure of the detector for X-ray absorption analysis. FIG. 2 is a perspective view of the detector according to the first embodiment of the present invention, and FIG. 3 is a perspective view of the rear end portion of the detector for X-ray absorption analysis according to the first embodiment of the present invention. Represents the appearance as seen.

  A detector 50 for X-ray absorption analysis of the first embodiment includes a cylindrical barrel 2a made of metal having a rectangular cross section, and a flange 2d for sealing front and rear ends thereof, with reference to FIGS. 2c. The trunk cylinder 2a and the flanges 2d and 2c are grounded, and the inner wall surface thereof is covered with an insulating layer 2g. Openings 2c-1 and 2d-1 are formed at the center of the flanges 2d and 2c, and allow X-rays 1 incident parallel to the cylinder axis of the barrel 2a to pass through without being blocked.

  Two guide plates 2h arranged in parallel are attached to the outside (front end direction) of the flange 2d of the front end 2F portion to form a dovetail groove 2f extending vertically. A sample holder 20 described later is inserted into the dovetail groove 2f from above. Further, the outer surface of the flange 2d (that is, the bottom surface of the dovetail groove 2f) is processed into a flat surface, and hermetic sealing with an O-ring is made possible.

  The stopper 2e is fixed to the lower end of the dovetail groove 2f, and the sample holder 20 inserted into the dovetail groove 2f is positioned in the vertical direction with the lower end abutting against the stopper 2e.

  An O-ring groove 2c-3 including concentric dovetails surrounding the opening 2c-1 is formed on the outer surface of the flange 2c at the rear end 2R portion (that is, the surface of the rear end 2R). Further, stop holes 2d-1 and 2c-2 are formed in the flanges 2d and 2c, and the detector 50 connected to the front and rear can be fixed by screws through the stop holes 2d-1 and 2c-2. .

  Referring to FIG. 1, two X-ray intensity measuring electrodes 15a and 15b are arranged in the barrel 2a in parallel to the X-ray 1, and are closer to the front end than the X-ray intensity measuring electrodes 15a and 15b. The charge collecting electrode 16 is disposed on the surface.

  One X-ray intensity measurement electrode 15 a is supplied with a negative voltage from the power supply 10 via the switch 11, and the other X-ray intensity measurement electrode 15 b is connected to the ground potential via the current measuring instrument 14. The X-ray intensity measuring electrodes 15a and 15b absorb the electric charge generated every time the X-ray 1 passing through the barrel 2a ionizes the gas in the container 2, and the intensity of the X-ray 1 is measured by a current measuring instrument. A current pulse is measured. At this time, the detector 50 operates as a Geiger counter, and the X-ray intensity is measured. Note that the detector 50 may be operated as a proportional counter or an ionization chamber.

  The charge collecting electrode 16 is a plate-like electrode arranged perpendicular to the X-ray 1, and a small hole 16 a through which the X-ray 1 can pass without being shielded is opened at the center. Therefore, the X-ray 1 incident on the detector 50 passes through the container 2 and is emitted from the rear end 2R without being shielded by the charge collection electrode 16.

  A negative voltage is applied to the charge collection electrode 16 from the power supply 12 through the switch 13. As will be described later, the sample 32 is placed near the opening 2d-1 of the flange 2d at the front end 2F so that the X-ray 1 can pass therethrough. The electrons emitted from the sample 32 into the container 2 ionize the gas in the container 2 and are captured by the charge collecting electrode 16. As a result, a current corresponding to the amount of electrons emitted from the sample 32 flows through the sample 32. As will be described later, by measuring the current flowing through the sample 32, the amount of electrons emitted from the sample 32, and further The X-ray dose absorbed by the sample 32 can be known. Therefore, at this time, the detector 50 functions as a detector of an X-ray absorption analyzer using the electron yield method.

  The switch 11 and the switch 13 operate complementarily to each other. That is, when a negative voltage is applied to the X-ray intensity measurement electrode 15a, no negative voltage is applied to the charge collection electrode 16. Conversely, when a negative voltage is applied to the charge collection electrode 16, no negative voltage is applied to the X-ray intensity measurement electrode 15a. Accordingly, by selectively switching the switches 11 and 13, the detector 50 can be selected to function as an X-ray 1 intensity measuring device or an electron yield method detector.

  Further, a gas introduction port 17 is provided in front of the container 2, and an ionizing gas is introduced into the container 2 from here. The introduced gas is discharged from an exhaust port 18 provided behind the container 2.

  4A and 4B are explanatory views of the structure of the sample holder according to the first embodiment of the present invention. FIG. 4A is a plan view seen from the X-ray incident side (front end side of the container 2), and FIG. BB 'sectional view in a), FIG. 4 (c) is an AA' sectional view in FIG. 4 (a), and FIG. 4 (d) is a plane viewed from the X-ray emission side (the rear end side of the container 2). FIG.

  Referring to FIG. 4, the sample holder 20 according to the first embodiment of the present invention is in the vertical direction (the right side of FIGS. 4A, 4 </ b> C, and 4 </ b> D is up and the left side is down). A base 21 made of a long rectangular plate is used as a basic member. The long side surface of the base 21 is formed on the inclined surface 21a and processed into a trapezoidal cross section. Further, the rear end surface of the base 21 (the surface below the paper surface in FIG. 4C) is processed into a flat surface. With reference to FIG. 2, the base 21 is inserted into a holder insertion portion 2f formed of a dovetail groove formed in the connection portion 3 at the front end of the detector 50.

  A circular recess 23 that is substantially concentric with the axis through which the X-ray 1 passes is provided in the lower part of the base 21 so as to open in the front end direction, and the recess 23 is formed on the bottom surface of the recess 23 (the rear end surface of the base 21). A concentric opening 22 is opened. A spring groove 27 for accommodating a ring-shaped leaf spring is formed on the inner wall of the recess 23.

  A flat portion 24 is provided in a ring shape concentrically with the recess 23 on the front end side surface of the base 21 (hereinafter referred to as the front end surface of the base 21), and the front end surface of the base 21 outside thereof is lowered. Furthermore, a lead wire groove 25 reaching the recess 23 from the upper end of the base 21 is formed on the front end surface of the base 21. The lead wire groove 25 is configured as a tunnel-like communication hole in the flat portion 24 and does not appear on the surface. In this structure, when the flat portion 24 is sealed with an O-ring and the tunnel-like communication hole is sealed with an adhesive, the opening 22 is hermetically sealed from the outside air on the front end surface of the base 21.

  An O-ring dovetail groove 26 is provided concentrically with the recess 23 on the rear end surface of the base 21. The O-ring held in the O-ring dovetail groove 26 is in close contact with the front end surface of the flange 2b and hermetically seals between the opening 22 and the outside air on the front end surface of the base 21.

  FIG. 5 is an explanatory view of a sample holding method according to the first embodiment of the present invention. FIG. 5 (a) is a plan view of a fixing plate holding the sample, and FIG. 5 (b) is a sectional view thereof.

  Referring to FIG. 5, a sample 32 made of Ni flakes is fixed on a disk-shaped metal having a through hole 34 in the center, for example, a fixed plate 31 made of Cu so as to close the through hole 34. At this time, the through hole 34 is airtightly closed by the sample 32. Further, the sample 32 and the fixing plate 31 are connected by a conductor 33, for example, a conductive paste. The periphery and side surfaces of the upper surface of the fixing plate 31 are covered with an insulating film 31a.

  FIG. 6 is an explanatory diagram of the connecting portion according to the first embodiment of the present invention, and shows the structure of the connecting portion that is airtightly connected by the sample holder. 6A shows a cross section of the sample holder on which the sample is mounted, FIG. 6B shows a cross sectional structure in the vicinity of the connecting portion of the two connected detectors, and FIG. 6C shows the sample holder. The cross section of the connection part vicinity in which is inserted is represented.

  With reference to FIG. 6A, the fixing plate 31 is inserted into the recess 23 of the base 21 with the sample 32 facing the rear end side (downward on the paper surface), and the annular shape fitted into the spring groove 27 from the front end side. It is suppressed and fixed by the spring 24a. The lead wire 35 is embedded in the lead groove 25 (the lead groove 25 shown in FIGS. 4A and 4C), and the tip thereof is connected to the front end side of the fixing plate 31. Note that immediately below the flat surface 24, the lead wire passes through the tunnel-shaped communication hole, and the outlet or entrance of the communication hole is sealed with an adhesive. Further, an O-ring is inserted into an O-ring dovetail groove 26 provided on the rear end surface of the base 21.

  With reference to FIG.6 (b), the flange 2d of the front end of the rear detector 50 and the flange 2c of the rear end of the front detector 50 are fixed by screwing. At this time, an O-ring is inserted in advance into the dovetail O-ring groove 2c-3 provided in the front flange 2d. At this time, the holder insertion portion 2f is disposed between the flanges 2c and 2d so as to open upward (to the right in the drawing).

  Referring to FIG. 6 (c), the holder holder 2f (holder insert part 2f shown in FIG. 6 (b)) is rubbed with the rear end face of the sample holder 20 against the front end face of the flange 2d. insert. The sample holder 20 contacts the stopper 2e and is positioned in the insertion direction (vertical direction). The left and right positions are positioned by the dovetail groove of the holder insertion portion 2f. At this time, as described above, the O-ring 28 (O-ring 28 shown in FIG. 6B) held in the O-ring groove 2c-3 formed on the rear end surface of the flange 2c is formed on the front end surface of the sample holder 20. The air tightness with the outside air is maintained in close contact with the flat portion 24 on the front end surface of the sample holder 20. In addition, the O-ring 26a held in the O-ring dovetail groove 26 formed on the rear end surface of the sample holder 20 is brought into close contact with the front end surface of the flange 2d at the rear end surface of the sample holder 20, so that airtightness with the outside air is prevented. Retained.

  In addition, the airtightness between the interiors of the containers 2 of the connected detectors 50 before and after the connection is achieved by the sample 32 closing the through-hole 34 formed in the fixing plate 31. Note that the through hole 34 may be sealed with an X-ray transmitting material instead of the sample 32. In this manner, by separating the front and rear detectors 50 in an airtight manner, different gases can be caused to flow in each detector 50. If necessary, the front and rear detectors 50 can be used in a conductive state without sealing the through hole 34.

  In the first embodiment of the present invention described above, the charge collecting electrode 16 and the X-ray intensity measuring electrodes 15a and 15b are provided, and either one is selected and used. On the other hand, as a modification, an X-ray absorption analysis detector including the charge collection electrode 16 or the X-ray intensity measurement electrodes 15a and 15b can be used.

  Although the detector of this modification can connect a plurality of detectors by the connection part 3 (3-1 to 3-3 shown in FIG. 7) similarly to the first embodiment, the measurement or incidence by the charge yield method is possible. It differs from the detector of the first embodiment in that only one of the X-ray intensity measurements can be performed. This detector has a drawback that it is difficult to change the measurement method after connecting a plurality of detectors, but there is an advantage that a detector having a simpler structure can be used in applications where the measurement method is predetermined.

  The second embodiment of the present invention relates to an X-ray absorption fine structure analyzer that simultaneously performs measurement by an electron yield method and a transmission method.

  FIG. 7 is a cross-sectional view of the detector section of the X-ray absorption fine structure analyzer of the second embodiment of the present invention, and schematically shows the structure of the detector section configured by connecting three detectors.

  With reference to FIG. 7, the detection part 55 of the apparatus of 2nd Embodiment is comprised by connecting the three detectors 51, 50-2, and 50-3 back and forth. The detector 51 located at the foremost end (incident direction of the X-ray 1) is the detector 51 described as a modification of the first embodiment, and has X-ray intensity measurement electrodes 15a and 15b, and is used for charge collection. The electrode 16a is not provided.

  A negative voltage is applied from the electric key 10 to the X-ray intensity measuring electrode 15 a of the detector 51, and the X-ray intensity measuring electrode 15 b is grounded via the current detector 14. The detector 51 operates as a proportional counter or Geiger counter, and the X-ray intensity is measured by the current detector 14 as the number of pulses of current.

  No other detector is connected to the front end of the connection part 3-1 of the detector 51 located at the front end. On the other hand, the sample holder 20-1 is inserted into the connection part 3-1. A fixing plate 31 having a through hole 34 closed with an X-ray transmitting material 37, for example, Kapton or beryllium foil, is fitted into the recess 23 of the sample holder 20-1 (the recess 23 shown in FIG. 6A). As a result, the opening 22 and the through hole 34 of the sample holder 20-1 are airtightly closed by the fixing plate 31 and the X-ray transmitting material 37, respectively. The through hole 34 constitutes a window that transmits X-rays. Furthermore, the opening 2d-1 opening in the flange 2f constituting the connection part 3-1 is airtightly closed by the sample holder 20-1.

  The detector 50-2 arranged in the center has the same configuration as the detector 50 of the first embodiment described above. This detector 50-2 operates as a detector using the charge collection method, and the detector 50-3 disposed at the end is an X-ray intensity measuring detector for measuring the intensity of X-ray 1 transmitted through the sample 32. Works as. In order to perform such an operation, in the detector 50-2, the switch 11-2 is turned off, the switch 13-2 is turned on, and no voltage is applied to the X-ray intensity measurement electrode 15a. Apply voltage to

  A sample holder 20-2 in which a fixing plate 31 having a through hole 34 closed with a Cu foil, for example, is inserted is inserted into the connecting portion 3-2 at the front end of the detector 50-2. Thus, the front and rear detectors 51 and 50-2 are separated in an airtight manner, and the airtightness between the outside air and the detectors 51 and 50-2 is maintained.

  Further, the lead wire 35 connected to the sample 32 is connected to the lead wire groove 25 (FIGS. 4A and 4C) on the sample holder 20-2 inserted into the connecting portion 3-2 at the front end of the detector 50-2. Embedded in the lead wire groove 25) shown in FIG. The lead wire 35 is grounded via a current measuring device 19, for example, a current pulse counter, and the current flowing through the sample 32 can be measured.

  The detector 50-3 arranged at the end has the same configuration as the detector 50 of the first embodiment, like the detector 50-2. This detector 50-3 operates as a Geiger counter, for example, and operates as an X-ray intensity measuring device that measures the intensity of X-ray 1 transmitted through the sample 32. Therefore, in the detector 50-3, the switch 11-3 is turned ON, the switch 13-3 is turned OFF, the voltage is applied to the X-ray intensity measurement electrode 15a, and the voltage is not applied to the charge collection electrode 16a. .

  The sample holder 20-2 into which the fixing plate 31 with the through hole 34 closed by the X-ray transmitting material 37 is inserted is inserted into the connecting portion 3-3 at the front end of the detector 50-3. Thereby, the front and rear detectors 50-2 and 50-3 are separated in an airtight manner, and the airtightness between the outside air and the detectors 50-2 and 50-3 is maintained.

  In FIG. 7, a lead wire 35 is drawn from the upper end of the sample holder 20-3 to the sample holder 20-3 inserted into the connecting portion 3-3 at the front end of the detector 50-3. Since it is not necessary to measure the current of the wire 35, the lead wire 35 can be removed. At this time, the lead wire groove 25 (a communication hole) immediately below the flat portion 24 of the sample holder 20-2 is sealed with an adhesive.

  A plate 36 that hermetically seals the rear end of the detector 50-3 is attached to the rear end flange 2c (the flange 2c shown in FIG. 1) at the rear end of the detector 50-3 disposed at the rearmost position. . The plate 36 is provided with a window sealed with an X-ray transmissive material 37 through which the X-ray 1 passes, and the X-ray 1 incident on the detector 50-3 passes through the window sealed with the X-ray transmissive material 37. It is emitted to the outside.

  Next, the operation of the detector unit 55 having such a structure will be briefly described. The X-ray 1 that enters the through hole 34 at the front end of the detector unit 55 (the front end of the detector 51) passes through the X-ray transmissive material 37 held by the sample holder 20-1 and enters the detector 51. The intensity of the incident X-ray 1 is measured when passing through the detector 51, and the sample 32 held by the sample holder 20-2 is irradiated and transmitted through the sample 32.

  Auger electrons are emitted from the back surface (rear end surface) of the irradiated sample 32, and the charge of ions generated by ionizing the gas by the electrons is absorbed by the electron collecting electrode 16 of the detector 50-2. As a result, the current flowing through the lead wire 35 is measured by the current measuring device 19.

  The X-ray 1 transmitted through the sample 32 passes through the small hole 16a formed in the electron collecting electrode 16, travels inside the detector 50-2, and is held in the sample holder 20-3. 37 penetrates into the detector 50-3.

  X-ray intensity that has entered the detector 50-3 is measured by the detector 50-3, and is emitted to the outside through a window (X-ray transmitting material 37) provided on the plate 36 at the rear end.

  In the present detector section 55, the X-ray intensity before and after transmission through the sample 32 is measured by the detector 51 and the detector 50-3. Based on the measurement result, the X-ray absorption spectrum of the sample 32 by the transmission method can be measured. At the same time, an X-ray absorption spectrum by the electron yield method is measured by the detector 50-3. Therefore, the measurement of the X-ray absorption spectrum by both the transmission method and the electron yield method can be performed at the same time in one measurement.

  In the second embodiment, the detectors 51 and 50-3 for measuring the X-ray intensity include a gas having a large atomic weight that is easily ionized by the X-ray 1 having a wavelength near the absorption edge of the sample 32, for example, nitrogen, Argon or krypton or a mixture of these two or three kinds of gases is preferably introduced from the viewpoint of sensitivity. On the other hand, it is desirable to flow a gas having a small atomic weight, for example, He, which is easily ionized by Auger electrons, into the detector 50-2 that performs measurement by the electron yield method. As a result, the background caused by incident X-rays and fluorescent X-rays is reduced and sensitivity is improved, and attenuation of the X-ray 1 in the detector 50-2 is reduced to improve the accuracy of the transmission method. it can.

  FIG. 8 is a perspective view of an X-ray absorption fine structure analyzer according to the second embodiment of the present invention, showing the arrangement of the analyzer.

  Referring to FIG. 8, X-rays emitted from X-ray source 41 are shaped into a beam having a rectangular cross section through two slits 42 and enter monochromator 43. The monochromator 43 is placed on the central rotation axis of the two-axis rotation table 44. The arm 45 is fixed to the outer turntable of the rotary table 44, and the detector unit 55 is placed on the table 46 installed on the arm 45. X-rays emitted from the monochromator 43 enter the detector unit 55.

  The table 46 moves in the horizontal direction (x-axis direction) perpendicular to the arm 45 (z-axis direction) and in the extension direction of the arm 45, and rotates around the z-axis (θ rotation) and rotates in the xz plane. Has been made possible. As a result, the detector unit 55 is adjusted in the horizontal and vertical directions and the position in the xz plane (ie, the sample position).

  FIG. 9 is a cross-sectional view of the detector section of the X-ray absorption fine structure analyzer of the third to fifth embodiments of the present invention, and the type of detector constituting the detector section and the material that closes the through hole of the sample holder Represents the relationship.

  In FIG. 9, the detector 61 applies a voltage to the X-ray intensity measurement electrodes 15 a and 15 b to measure the X-ray intensity, and the detector 60 applies a voltage to the electron collection electrode 16. It represents a detector that applies an electron yield method for measurement. In FIG. 9, the sample holder 20A is the sample holder 20 in which the through hole 34 is closed by the X-ray transmitting material 37, the sample holder 20B is the sample holder 20 in which the through hole 34 is closed by the sample 32, and the sample holder 20C. Represents the sample holder 20 in which the through hole 34 is not closed.

  In the third embodiment of the present invention, referring to FIG. 9A, three detectors 61 for X-ray intensity measurement are connected in series. Two samples 32 are held by two sample holders 20 </ b> B inserted in connection portions at the front ends of the second and third detectors 61. In this configuration, the detectors 61 that measure the X-ray intensity are arranged before and after the sample holder 20 that holds the sample 32, so that the X-ray intensity before and after each sample 32 can be measured. For this reason, the absorption spectrum for every sample 32 is measured simultaneously. The sample 32 may be the same type or different type.

  The detector unit 55 according to the fourth embodiment of the present invention includes five detectors 61 and 60, an X-ray intensity measurement detector 61 and an electron yield method detector 60 with reference to FIG. 9B. And are connected so as to be alternately arranged. The state-of-the-art detector 61, the third detector 61, and the sample holder 20A inserted at the front ends of the fifth detector 61 and the rear end of the fifth (last) detector 61 are X-ray transmitting materials. A window that transmits X-rays blocked by 37 is provided. On the other hand, a sample holder 20 </ b> B that holds the sample 32 is inserted into the front ends of the second and fifth detectors 60.

  In the detector section 55 of the fourth embodiment, a detector 60 provided with the electron yield electrode 16 is arranged immediately after the sample holder 20B holding the sample 32. Accordingly, the absorption spectra of the two samples 32 can be simultaneously measured using the electron yield method by the two detectors 60 arranged immediately after each sample.

  Further, detectors 61 for measuring the X-ray intensity are arranged before and after the detector 60 having each sample holder 20 </ b> B for holding the sample 32. Therefore, the intensity of X-ray 1 before and after passing through each sample 32 can be measured. Thereby, the X-ray absorption spectrum for each sample can be measured by the transmission method.

  As described above, according to the detector unit 55 of the fourth embodiment, the X-ray absorption spectra of two samples are measured for each sample by the transmission method and the electron yield method by one measurement. Can do.

  The detector unit 55 according to the fifth embodiment of the present invention has two detectors that connect the last detector 61 of the detector 55 according to the fourth embodiment in series with reference to FIG. This is a replacement for 61.

  The two detectors 61 for X-ray detection located at the tail end of the sample holder 20C inserted into the connecting portion 3 between them do not insert the fixing plate 31 or block the through hole 34 of the fixing plate 31. Not. Therefore, the last two detectors 61 are in communication.

  In the detector unit 55 of the fifth embodiment, the two detectors 61 are in communication with each other, and the X-ray absorption therebetween is small, and the incident X-rays are detected by the two detectors 61. High measurement accuracy is achieved.

  The detector unit 55 of the second to fifth embodiments described above can be configured as an integrated detector. That is, the integral detector container is separated into a plurality of sections along the X-ray passage axis by the separation unit. In the detector of the sixth embodiment of the present invention, referring to FIG. 9, the outer walls of the containers of a plurality of detectors 60 and 61 to be connected are used as containers, and the joints (positions of sample holders 20A to 20C) are used as containers. It replaces with the separation part to separate.

  The separation part is formed with a sample holder similar to the sample holders 20A to 20C of the second to fifth embodiments and its insertion part, and the detectors on both sides of the separation part can be separated in an airtight manner. Further, the separation part is kept airtight between the inside and outside of the detector container by inserting the sample holder.

  Each section of the detector can select any one of the functions of both the X-ray intensity measurement and the electron yield method as in the detector of the first embodiment. Therefore, by appropriately selecting and using any of the functions, the detector shown in FIG. 7 or FIG. 9 can be easily constructed simply by switching the switch applied to the electrode. Therefore, various measurements can be easily performed.

The present invention described above discloses the invention described in the following supplementary notes.
(Appendix 1) A detector for X-ray absorption analysis using gas ionization by radiation irradiation,
A connecting portion that is provided at a front end of the container of the detector and connects the other detector while maintaining airtightness between the inside of the container and outside air;
A through-hole provided in the connecting portion and hermetically closed by a sample or an X-ray transmitting material;
X-ray absorption analysis detection, comprising: an X-ray intensity measurement electrode that collects charges generated in the container by X-rays incident through the through-hole and passing through the container vessel.
(Supplementary note 2) The X-ray absorption analysis detector according to supplementary note 1, wherein the X-ray intensity measurement electrode comprises a pair of parallel plate electrodes arranged in parallel to incident X-rays.
(Supplementary note 3) For collecting charges generated by electrons emitted from the sample, which are disposed in the container in the vicinity of the through-hole and have a small hole through which the X-ray passes. Electrodes,
The detector for X-ray absorption analysis according to appendix 1 or 2, further comprising a current detection unit for measuring a current flowing through the sample.
(Supplementary note 4) The detector for X-ray absorption analysis according to supplementary note 3, wherein the charge collection electrode is disposed at a position closer to the front end than the X-ray intensity measurement electrode.
(Appendix 5) A detector for X-ray absorption analysis utilizing ionization of gas by radiation irradiation,
A connecting portion that is provided at a front end of the container of the detector and connects the other detector while maintaining airtightness between the inside of the container and outside air;
A through-hole provided in the connecting portion and hermetically closed by a sample or an X-ray transmitting material;
A charge collecting electrode for collecting charges generated by electrons emitted from the sample, the small electrode penetrating the X-ray disposed in the container in the vicinity of the through hole;
A detector for X-ray absorption analysis, comprising: a current detector for measuring a current flowing through the sample.
(Supplementary note 6) The detector for X-ray absorption analysis according to supplementary notes 3, 4 or 5, wherein the charge collection electrode comprises a plate electrode perpendicular to the traveling direction of the X-ray.
(Supplementary note 7) a slit-shaped sample holder having a through-hole that can be airtightly closed by a sample or an X-ray transmitting material;
Any one of Supplementary notes 1 to 6, further comprising a holder insertion portion that is provided in the connection portion and is insertable so that airtightness between the inside of the detector and the outside air is maintained after the sample holder is inserted. The detector for X-ray absorption analysis of description.
(Supplementary note 8) the first detector in which the through hole is blocked by a sample;
A second detector connected to the rear of the first detector and having the through-hole closed by an X-ray transmissive material;
In the first detector, an operating voltage is applied to the charge collecting electrode, no operating voltage is applied to the X-ray intensity measuring electrode, and the current detector is operated to perform measurement by the electron yield method. Done
The second detector measures the X-ray intensity by applying an operating voltage to the X-ray intensity measuring electrode without applying an operating voltage to the charge collecting electrode. An X-ray absorption fine structure analyzer using the X-ray absorption analysis detector according to 3 or 4.
(Supplementary note 9) A plurality of detectors for X-ray absorption analysis according to any one of supplementary notes 1 to 7 are connected to the front and rear,
An X-ray absorption fine structure analyzer characterized in that each of the detectors is used for X-ray intensity measurement or measurement by an electron yield method.
(Supplementary note 10) The X-ray absorption fine structure analyzer according to supplementary note 8 or 9, wherein the gas flowing in the detector is different depending on whether it is for X-ray intensity measurement or measurement by electron yield method. .
(Additional remark 11) The said gas is one gas selected from nitrogen, argon, and krypton at the time of X-ray intensity measurement, or two or more mixed gas, and helium at the time of the measurement by an electron yield method 10. The X-ray absorption fine structure analyzer according to 10.
(Supplementary Note 12) A separation unit that separates the detector container into a plurality of sections along the X-ray passage axis;
A through-hole provided at a position where the X-ray of the separation portion is transmitted and can be airtightly closed by a sample or an X-ray transmitting material;
An X-ray intensity measuring electrode provided in the compartment and collecting charges generated in the compartment by X-rays passing through the compartment;
A charge collecting electrode for collecting charges generated by electrons emitted from the sample, the small electrode penetrating the X-ray provided in the compartment;
A detector for X-ray absorption analysis, comprising: a current detector for measuring a current flowing through the sample.

  Since the present invention can be used in an analyzer that measures and analyzes an X-ray absorption spectrum of a sample, the measurement time can be shortened, so that it can greatly contribute to material development.

Sectional view of detector according to the first embodiment of the present invention 1 is a perspective view of a detector according to a first embodiment of the present invention. First embodiment of the present invention detector rear end perspective view 1st Embodiment of this invention Sample holder structure explanatory drawing 1st Embodiment of this invention Sample holding method explanatory drawing 1st Embodiment connection part explanatory drawing of this invention Sectional view of detector section of X-ray absorption fine structure analyzer of second embodiment of the present invention Second embodiment of the present invention X-ray absorption fine structure analyzer perspective view Sectional view of detector section of X-ray absorption fine structure analyzer of third to sixth embodiments of the present invention Diagram showing X-ray absorption spectrum Cross-sectional view of a conventional electron yield method measuring device Conceptual diagram of conventional X-ray combined analyzer Cross section of conventional X-ray detector

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X-ray 2 Container 2a Body cylinder 2c, 2d Flange 2c-1, 2d-1 Opening 2c-3 O-ring groove 2e Stopper 2f Holder insertion part 2g Insulating layer 2F Front end 2R Rear end 3 Connection part 10,12 Power supply 11,13 Switches 14, 19 Current measuring instruments 15a, 15b X-ray intensity measuring electrode 16 Charge collecting electrode 16a Small hole 17 Gas inlet 18 Exhaust outlet 20, 20A, 20B, 20C Sample holder 20a Lower end 21 Base 21a Slope 22 Opening 23 Recess 24 Flat part 25 Lead wire groove 26 Dovetail groove 26a, 28 O ring 27 Spring groove 31 Fixing plate 31a Insulating film 32 Sample 33 Conductor 34 Through hole 35 Lead wire 36 End flange 37 X-ray transmitting material 40 X X-ray absorption fine structure analyzer 41 X-ray source 42 Slit 43 Monochromator 44 Rotating table 45 Arm 46 Table 50, 50-2, 50-3, 51, 60, 61 Detector 55 Detector part 101 X-ray 101a Incident X-ray 101b Transmitted X-ray 120 Chamber 120a Insulating layer 121 Sample holder 122 Sample 123 Conductive wire 124 window 125 charge collection electrode 126a gas introduction port 126b exhaust port 127 current measuring device 128 power source 130, 131 X-ray detector 132 sample 133 sample holder 134 slit 135 fluorescent X-ray

Claims (4)

A detector for X-ray absorption analysis using gas ionization by radiation irradiation,
Provided at the front end of the container of the detector, and a connecting portion connecting holding the airtightness between the front SL container interior and the outside air to the rear end of the other of said detectors,
A through-hole provided in the connecting portion and hermetically closed by a sample or an X-ray transmitting material;
An X-ray intensity measuring electrode that collects charges generated in the container by X-rays that are incident through the through-hole and pass through the container ;
A charge collecting electrode for collecting charges generated by electrons emitted from the sample, the small electrode penetrating the X-ray disposed in the container in the vicinity of the through hole;
A detector for X-ray absorption analysis, comprising: a current detector for measuring a current flowing through the sample . A detector for X-ray absorption analysis using gas ionization by radiation irradiation,
Provided at the front end of the container of the detector, and a connecting portion connecting holding the airtightness between the front SL container interior and the outside air to the rear end of the other of said detectors,
A through hole provided in the front end connecting portion, which can be airtightly closed by a sample or an X-ray transmitting material;
A charge collection electrode for collecting charges generated by electrons emitted from the sample, the small electrode through which the X-ray penetrates and disposed near the through hole in the container;
A detector for X-ray absorption analysis, comprising: a current detector for measuring a current flowing through the sample. A sample holder having a through hole that can be hermetically closed by a sample or an X-ray transmitting material;
3. A holder insertion portion, which is provided at the front end connection portion and can be inserted so that airtightness between the inside of the detector and the outside air is maintained after insertion of the sample holder. Detector for X-ray absorption analysis. A separation unit for separating the detector container into a plurality of sections along the X-ray passing axis;
A through-hole provided at a position where the X-ray of the separation portion is transmitted and can be airtightly closed by a sample or an X-ray transmitting material;
An X-ray intensity measuring electrode provided in the compartment and collecting charges generated in the compartment by X-rays passing through the compartment;
A charge collecting electrode for collecting charges generated by electrons emitted from the sample, the small electrode penetrating the X-ray provided in the compartment;
A detector for X-ray absorption analysis, comprising: a current detector for measuring a current flowing through the sample.

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