JP2009210371A - Low acceleration voltage x-ray microscope device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray microscope device can obtain sufficient high resolution, high contrast even for a micro sample composed of light elements and observing the sample in-situ state. <P>SOLUTION: An X-ray microscope device is provided with an X-ray generating means irradiating the electron beam from the electron source of an electron gun to the X-ray target to generate X-ray and an imaging means imaging the transmission X-ray irradiated to a sample with imaging elements. The X-ray generating means generates characteristic X-ray having long wavelength of 0.1-1.2 nm wavelength. An X-ray transmission window base material for vacuum sealing the X-ray target is composed of beryllium and the thickness of the X-ray transmission window base material is 10-60 nm. The sample chamber of the imaging means makes a sealed structure. The transmission image of the sample is obtained by the imaging means while filling the sample chamber with a gas. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an X-ray microscope apparatus that performs observation (or inspection) by irradiating a sample (inspected object) with X-rays, and in particular, thin beryllium (10 to 60 μm) as an X-ray transmission window substrate for vacuum sealing. Be) A low acceleration voltage drive type that uses a plate material, generates characteristic X-rays having a long wavelength of 0.1 nm to 1.2 nm in the X-ray generation unit, and observes the sample in helium (He) gas. The present invention relates to an X-ray microscope.

  FIG. 8 shows an example of the structure of a conventional X-ray microscope 100, and FIG. 9 shows an internal configuration example of an open X-ray tube 110 as X-ray generation means. An X-ray tube 110 that generates an electron beam and irradiates the X-ray target 111 is disposed above the X-ray microscope 100, and the X-ray emitted from the X-ray target 111 is placed or held on the stage mechanism 101. The transmitted sample 102 is transmitted, and the transmitted X-rays are taken into an imaging tube 103 as imaging means disposed below. A cover (not shown) for preventing X-ray leakage to the outside is disposed around the sample 102, and the sample 102 is placed in the atmosphere. In addition, in order to increase the geometric magnification of the X-ray image, the sample 102 is placed near the X-ray target 111, and the imaging tube 103 is disposed at an appropriate distance.

  In the open X-ray tube 110, as shown in FIG. 9, the inside is evacuated to a vacuum state by a vacuum pump (not shown), and a thermionic emission cathode 112 that emits thermoelectrons by current heating is used as an electron source. By applying a high voltage of 40 kV to 120 kV between the electron emission cathode 112 and the anode 114, the electrons Re emitted from the thermion emission cathode 112 are accelerated, and a beryllium (Be) plate material (X Electrons Re are focused by an electron lens 115 on an X-ray target 111 made of tungsten (W) placed on a (transmission window base material) to obtain a fine point X-ray source. Then, the inside of the sample 102 is enlarged and projected in the atmosphere using the point X-rays Rx generated from the X-ray source on the X-ray target 111, and an imaging tube composed of an II (Image Intensifier), CCD, or CMOS imaging device. In 103, the fine structure inside the sample 102 is non-destructively seen through.

  As the electron source, in addition to the thermionic emission cathode 112, a thermionic emission cathode that emits electrons by current heating and a strong electric field is also used.

  In such an X-ray microscope, the electron Re that collides with the X-ray target 111 is converted into X-ray Rx, but the conversion efficiency is extremely low at 1% or less, and most of the energy of the electron Re is X-ray target 111. Is converted to heat. By the way, since X-rays have no electric charge, they cannot be bent freely using an electron lens like electrons. Therefore, in order to obtain a large magnification, the sample 102 is placed as close as possible to the pointed X-ray source of the X-ray target 111, and the X-rays Rx that pass through the sample 102 and spread radially are arranged as far as possible. It is necessary to capture the image with the image pickup tube 103 to form an image. Theoretically, the larger the distance between the sample 102 and the imaging tube 103, the higher the magnification. However, in actuality, the X-ray dose per unit area attenuates in inverse proportion to the square of the distance. The upper limit of the magnification is determined by the balance between the sensitivity of the tube 103 and the X-ray dose of the magnified image.

  On the other hand, the resolution of the X-ray image transmitted through the sample 102 is improved when the X-ray source size (focal size) is smaller and the amount of blur is reduced. However, when the same thermionic emission cathode 112 is used, the X-ray source size can be reduced by converging it with the electron lens 115, but the electron dose contained therein decreases in inverse proportion to the square of the spot diameter. Since it decreases accordingly, the final resolution depends on the sensitivity of the image pickup tube 103 and has a certain limit.

  By the way, in the X-ray microscope, observation of water droplets and water composed of hydrogen and oxygen are both light elements and have been considered impossible in the past because of little X-ray absorption. For this reason, in the conventional X-ray microscope, for example, water generated in the fuel cell could hardly be observed.

Explaining the observation of water generated in the fuel cell, hydrogen (H ₂ ) and oxygen (O ₂ ) are combined to generate water in the fuel cell during power generation. It has been found that this water greatly reduces power generation efficiency by hindering the flow of hydrogen and oxygen. However, the mechanism of how water droplets are generated and grown from which part is not well understood. By analyzing the mechanism of water generation in the fuel cell, it is expected to contribute to improving the performance of the fuel cell.

As a conventional technique related to observation of water droplets in a fuel cell, an observation method characterized by relatively easy detection of hydrogen in water molecules, such as radiation images using thermal neutrons or images using a nuclear magnetic resonance apparatus (MRI) Although it has been observed, it is impossible to observe a very small thing of 10 to several tens of μm, which is the initial stage of water droplet generation, and the fact that only a very large growth of 100 to several hundreds of μm has been observed at present. .
JP 2005-221362 A JP 2003-207466 A Japanese Patent No. 4029209 Kenji Oohashi, Keiji Yada, Kohei Shirota, Hiromi Kai, Yasushi Saito `` Low-Voltage Projection X-Ray Microscope for Inspection of Lighter Elements '' IMC 16 (Poster session: P7I_86, 2006.9.3-9.8)

  In the current X-ray microscope, a sufficient image contrast cannot be obtained with respect to a fine structure composed of light elements in a sample. In addition, hydrogen and oxygen combine to produce water during fuel cell power generation, and it is expected to clarify the mechanism by which this water is generated and how it grows. However, no X-ray microscope apparatus that can meet the demand has appeared.

  In addition, the thickness of a conventional beryllium X-ray transmissive window base material is about 250 μm, and the X-ray absorption of the window base material portion at that thickness is small, and there is no problem. On the other hand, when using long-wavelength X-rays for light element observation, the absorption of the beryllium window base material cannot be ignored, so it is necessary to further reduce the thickness in order to reduce the absorption. Conventionally, further thinning the X-ray transmission window base material has not been considered for the following reason. In other words, beryllium is easily corroded by gas containing chlorine, etc., and pinholes are easily formed from the internal structure. Therefore, if it is made thin, vacuum leakage is likely to occur, and attempts to make the X-ray transmission window substrate extremely thin Not done.

  The present invention has been made under the circumstances as described above, and the object of the present invention is to obtain a sufficiently high resolution and high contrast even for a minute sample made of a light element. An object of the present invention is to provide a low acceleration voltage driven X-ray microscope capable of observing a sample in a state.

  It is another object of the present invention to provide a fuel cell having a structure suitable for observation with an X-ray microscope.

  The present invention provides an X-ray generation means for generating an X-ray by applying an electron beam from an electron source of an electron gun to an X-ray target, and imaging for imaging the transmitted X-ray of the X-ray irradiated to a sample with an imaging device. The above object of the present invention is to provide an acceleration voltage of the electron beam of 6 to 30 kV, and an X-ray transmission window base material for vacuum-sealing the X-ray target is made of beryllium. The X-ray transmission window base material has a thickness of 10 to 60 μm, and the sample chamber of the imaging unit has a hermetically sealed configuration, and the sample chamber is filled with gas to obtain a transmission image of the sample by the imaging unit. Or the X-ray generation means generates a characteristic X-ray having a long wavelength of 0.1 nm to 1.2 nm, and the X-ray transmission window base material for vacuum-sealing the X-ray target is made of beryllium, The thickness of the X-ray transmission window substrate is 10 to 60 μm In addition, the sample chamber of the imaging unit has a sealed configuration, and the sample chamber is filled with a gas and a transmission image of the sample is obtained by the imaging unit.

  The object of the present invention is that the gas is helium gas, or the X-ray target is made of germanium, chromium, vanadium or gold, and the characteristic X-ray is the germanium, chromium or 3D observation is possible by using Kα ray of vanadium, Mα ray of gold, or by placing or holding the sample on a stage mechanism and moving and tilting the sample by the stage mechanism. Is achieved more effectively.

  Further, the present invention is a fuel cell for X-ray observation, wherein a metal cover having a plurality of holes formed on the front and back of the fuel cell body is layered, and a polymer film or A beryllium plate is layered, or the polymer film has mechanical strength and has a characteristic of easily transmitting long wavelength X-rays.

  According to the present invention, a long-wavelength characteristic X-ray with a wavelength of 0.1 nm to 1.2 nm is generated from an X-ray generation unit composed of an X-ray target and an X-ray transmission window base material, and a beryllium plate material having a thickness of 10 μm to 60 μm is obtained. Because it is used as a base material for X-ray transmission window for vacuum sealing and captures a transmission image of the sample in the helium gas chamber, even a light element material sample should be observed with high resolution and high contrast. Can do.

  In addition, water droplets and moisture are generated in the reaction chamber that generates electricity by electrochemical reaction of hydrogen and oxygen, for example, in-situ observation of water droplet generation during fuel cell power generation. A high-resolution, high-contrast observation is possible by layering a metal cover provided with a beryllium plate or a polymer film on the inner or outer surface of the metal cover so as to block the hole. Can do.

  Similarly, since the observation is performed in the helium gas chamber, it is possible to observe a biological sample containing an organic material or moisture with high resolution and high contrast.

  In the X-ray microscope, the longer wavelength components of X-rays are more susceptible to absorption in the air, and long-wavelength X-rays with a wavelength of 0.1 nm or more pass through an air layer made of nitrogen, oxygen, etc. for a short distance. Attenuation will greatly decrease. However, if the sample chamber from the X-ray target, which is a point X-ray source, to the imaging device is evacuated or filled with helium gas, which is an inert gas, long-wavelength X-rays with a wavelength of 0.1 nm or more are obtained. Attenuation can be suppressed.

  In addition, the contrast image corresponding to each elemental component generated by absorption of carbon, oxygen, nitrogen, etc. in the sample is absorbed by the longer wavelength X-ray component while traveling in the air, and therefore reaches the image sensor. In this case, a low-contrast image containing many short wavelength components from which the long wavelength components are lost is obtained. When a vacuum or a gas with little X-ray absorption is used instead of air, X-ray absorption does not occur, and the contrast image of the sample is transmitted to the image sensor without deterioration. By observing in a sample chamber filled with helium gas, it is difficult to absorb long wavelength X-rays having a wavelength of 0.1 nm or more, and X-rays can be transmitted in a state close to vacuum. Since it is not under vacuum, evaporation of moisture and organic substances in the sample hardly occurs, and in-situ observation is possible. Since helium gas is light, the operation of sealing in the sample chamber is simple, and long-wavelength X-rays in the vicinity of a wavelength of 0.1 to 1.2 nm are hardly absorbed by helium gas at atmospheric pressure.

FIG. 1 shows that characteristic X-ray Cr-Kα rays (wavelength 0.229 nm) generated by using chromium (Cr) as an X-ray target are the main gases (nitrogen N ₂ , oxygen O ₂ ) and helium constituting the atmosphere. It is a characteristic view which shows how the distance and intensity which advance in 1 atmosphere of gas attenuate | damp. From this characteristic diagram, it can be seen that introduction of helium gas into the sample chamber is extremely effective.

  On the other hand, biological cells (C, O, N), water (O), and organic components composed of light element components are transmitted through short-wavelength X-rays. Although it has the property of not giving contrast, since it absorbs long-wavelength X-rays, an image with contrast according to the element content can be obtained. Note that helium is the only gas that has lower X-ray absorption than carbon, oxygen, and nitrogen, and other inert gases (neon, argon, xenon, etc.) have higher X-ray absorption than carbon, oxygen, and nitrogen. It cannot be used in the invention.

  The X-ray microscope can accurately observe the generation of internal water droplets during fuel cell power generation, increase the contrast of X-ray images of substances consisting of light elements (eg, biological samples), and improve image quality. Although strongly demanded, by using X-rays having a large absorption coefficient with respect to oxygen, such as long-wavelength characteristic X-rays such as chromium Kα rays (wavelength 0.229 nm), water droplets and moisture of several tens of μm can be observed. It has been found by the present inventors that this is possible. Therefore, in the X-ray observable fuel cell used in the present invention, a metal case having a plurality of holes provided on the front and back of the fuel cell body is layered, and a thin polymer film or By arranging the beryllium plates in layers, the structure is such that X-rays efficiently pass through the fuel cell during power generation. Since it is desired that the pressure inside the fuel cell is slightly higher than 1 atm, when the fuel cell is placed in a vacuum for X-ray observation, the polymer membrane or beryllium plate must withstand the pressure difference between the inside and outside of the fuel cell. The polymer film or beryllium plate becomes thick, so that the long wavelength component in the polymer film or beryllium plate is greatly absorbed. As a result, long-wavelength characteristic X-rays cannot be used effectively, and it is not possible to take a good image. Therefore, it is important that the polymer film or beryllium plate is a strong thin film that sufficiently transmits long-wavelength characteristic X-rays and has mechanical strength.

  On the other hand, the inside of the metal housing of the X-ray microscope is not evacuated, but helium gas is sealed at the same pressure as the inside of the fuel cell, so that a pressure difference is applied to the polymer film or beryllium plate layered on the fuel cell. Therefore, the film thickness can be reduced and the loss of characteristic X-rays with long wavelengths can be minimized.

  The conditions for selecting the material of the X-ray target are as follows. That is, the electron beam collides and becomes locally high temperature, so that the melting point temperature is high, the vapor pressure is low because it is used in vacuum, and the heat of the X-ray target needs to be dissipated so that the heat conductivity is good. In addition, since it is necessary to prevent charging by electrons, it is necessary that the electrical conductivity is good and that characteristic X-rays with a wavelength λ suitable for sample observation can be generated, and the wavelength λ = 0.1 nm to 1.2 nm. Table 1 below shows the combinations of target materials and characteristic X-rays suitable for the long wavelengths. Depending on the acceleration voltage of the electron beam, the wavelength spectrum of the characteristic X-rays generated by the X-ray target and the continuous X-rays changes. When the value is 2 to 3 times that of), an image with good contrast was obtained.

For the reasons described above, in the present invention, a characteristic X-ray having a long wavelength of 0.1 nm to 1.2 nm is generated with a low acceleration voltage (about 6 to 30 kV) to irradiate the sample, and an X-ray target and an X-ray transmission. An X-ray generation unit made of a window base material and a sample chamber from the sample to the imaging tube (imaging element) are sealed and filled with an inert gas (helium gas), and the transmitted X-rays of the sample are imaged with the imaging tube. By filling the sample chamber with helium gas, it is possible to effectively use long-wavelength characteristic X-rays with wavelengths of 0.1 nm to 1.2 nm. Further, in the embodiment using chromium (Cr) as the X-ray target material, in order to reduce the absorption of the long wavelength component of the X-ray generation part, the X-ray for vacuum sealing made of a beryllium plate having a thickness of about 60 μm. A transparent window base material prepared by vacuum deposition of chromium to a thickness of about 1.3 μm is used. By setting the acceleration voltage to about 15 kV, it is possible to observe a light element material sample, a minute organism, and water with high resolution and high contrast.

  Furthermore, for fuel cell observation, a metal cover provided with a plurality of X-ray observation holes is layered on the front and back of the battery body, and further, the inner surface has mechanical strength and long wavelength X-rays. A fuel cell structure in which thin polymer membranes or beryllium plates that are permeable to each other are layered, and the fuel cell is placed or held on a stage mechanism in the sample chamber, and an extremely early water droplet of about 10 μm generated inside the fuel cell And water can be observed. In addition, the stage mechanism can move and swivel the sample (fuel cell) placed or held, and three-dimensional observation is possible. The polymer film or beryllium plate does not need to be on each inner surface of the metal cover, and the same effect can be obtained by layering on each outer surface.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 2 is a sectional structural view showing an example of the configuration of the X-ray microscope according to the present invention. An open X-ray tube 10 as X-ray generation means and X-rays emitted from the X-ray tube 10 are used as a stage mechanism 21. The imaging means 20 includes an imaging tube 23 formed of an II, CCD, CMOS imaging device or the like that irradiates and images the upper sample (inspected object) 22. The open-type X-ray tube 10 has substantially the same configuration as the open-type X-ray tube 110 described with reference to FIG. 9 except that the applied voltage is a low voltage of 6 to 30 kV. That is, electrons emitted from a thermionic emission cathode (not shown) or a thermal field emission cathode are accelerated by a low voltage applied anode (not shown), and the electrons are generated by an electron lens (not shown). Focusing on the X-ray target 11 of the unit 16, a fine point X-ray source is obtained. The wavelength component of the generated X-ray consists of a continuous X-ray component and a characteristic X-ray component. The former is mainly determined by the voltage applied to the anode, and the latter is the element type of the X-ray target plate and the application to the anode. Determined by voltage.

  The imaging unit 20 includes a metal casing 24 that forms a hermetic sample chamber. An X-ray target 11 and an X-ray transmission window base material 14 are formed in an opening at the top of the metal casing 24. The X-ray tube 10 is connected so that the line generation unit 16 is located. A stage mechanism 21 is provided above the sample chamber. A sample 22 is placed on or held on the stage mechanism 21, and X-rays emitted from a point X-ray source of the X-ray target 11 are transmitted through an X-ray transmission window. The sample 22 is irradiated through the base material 14. The X-rays irradiated to the sample 22 are absorbed and attenuated inside the sample 22, and a contrast image due to the absorption is enlarged and projected as an image by the imaging tube 23 below the sample chamber. The housing 24 is provided with a sample exchange door 25 for placing or holding the sample 22 on the stage mechanism 21 or exchanging it, and an observation window 26 for visually observing the internal sample 22 from the outside. Further, a vacuum pump for evacuating the inside and a vacuum exhaust pipe 27 connected to a valve are provided, and a gas introduction pipe 28 for introducing helium gas is connected to the inside through a valve.

  FIG. 3 shows an example of the structure of the X-ray generation unit 16 in a partial cross-sectional structure. The X-ray generation unit 16 has a beryllium thickness so as to close the irradiation window 13 provided in the target holder 12 at the bottom of the X-ray tube 10. An X-ray generation part 16 comprising an X-ray transmission window base material 14 of d2 = 10 to 60 μm and a chromium X-ray target 11 is mounted on the target holder 12 by brazing 15 (or adhesive). In this example, the diameter D2 of the X-ray target 11 is about 3 mm, the diameter D3 of the X-ray transmission window base material 14 is about 4 mm, and the diameter D1 of the irradiation window 13 depends on the thickness d2 of the X-ray transmission window base material 14. It has a structure to let you.

  The surface on which the irradiation window 13 of the X-ray generator 16 is provided is in a vacuum, while the surface on the opposite side is subjected to atmospheric pressure. Therefore, the X-ray generator 16 needs to withstand the stress caused by this atmospheric pressure difference. Therefore, it is necessary to make the diameter D1 smaller as the thickness d2 of the X-ray transmissive window base material 14 is thinner. For example, when the thickness of the X-ray transmission window base material 14 is 60 μm, the diameter D1 = 1.5 mmφ or less is desirable, and when the thickness is 10 μm, the diameter D1 = 1.0 mmφ or less is desirable.

  Here, the X-ray transmissive window base material 14 used in the present invention will be described. As a necessary characteristic, long wavelength X-ray transmission is good, mechanical strength is strong enough to withstand the atmospheric pressure difference between the vacuum in the X-ray tube 110 and the outside air, and the heat generated in the X-ray target 11 is stored in the X-ray tube container. The thermal conductivity needs to be high so that the temperature of the X-ray target 11 is lowered. The material of the X-ray transmissive window base material 14 uses beryllium, which has a high X-ray transmittance and little absorption even for long-wavelength X-rays having a wavelength of 0.1 nm to 1.2 nm. In general-purpose X-ray tubes, aluminum materials, ceramic materials, and glass materials are sometimes used mainly from the viewpoint of manufacturing cost, but beryllium materials are used in X-ray tubes for low acceleration voltages. The beryllium material is about 250 μm thick × about 10 mmφ.

  And in this invention, in order to reduce attenuation by absorption inside beryllium (X-ray transmissive window base material 14) with respect to long wavelength characteristic X-rays having a wavelength of 0.1 nm to 1.2 nm, the X-ray transmissive window base material 14 is Thinner than before. FIG. 4 is a characteristic diagram showing the transmittance of the X-rays with wavelengths of 0.1 nm and 1.0 nm with respect to the thickness of beryllium. By setting the beryllium window thickness to 10 μm, 50% of the wavelength is 1.0 nm. The above X-ray transmission can be realized. In addition, the opening diameter D1 of the irradiation window 13 of the target holder 12 is reduced in accordance with the thin beryllium thickness, the area to which atmospheric pressure is applied is reduced, and the stress on the beryllium substrate is reduced. In addition, beryllium materials are susceptible to corrosion by corrosive gas components in the atmosphere, such as chlorine components, and are prone to pinholes due to internal structural defects. Degradation will cause failure. Therefore, in the present invention, the X-ray transmissive window base material 14 having a thickness d2 = 10 to 60 μm is employed in view of the balance between the attenuation intensity due to X-ray absorption and the generation of pinholes.

The X-ray target 11 is created as follows, for example. In other words, the mirror polished surface side of the beryllium X-ray transmission window base material and the deposited material are placed facing each other in a bell jar (fish bell-shaped glass container), and the vacuum state is removed by evacuating the air with a vacuum pump (10 ⁻³ to 10 ^-4 Pa). Next, when the deposited material (granular chromium) placed in the tungsten basket is melted by resistance heating, it forms a mist and adheres to the window substrate. The deposition thickness is controlled by the mass of the deposit, the distance between the window substrate and the deposit, the deposition time, and the like. The optimum deposition thickness differs depending on the element, but in the case of chromium, a good contrast image was obtained when the thickness d1 = 1.3 μm. The thickness of the vapor deposition layer can be measured using a stylus type surface shape measuring instrument or the like. Sputtering can also be used for vapor deposition of copper (Cu), tungsten (W), platinum (Pt), titanium (Ti), vanadium (V), tantalum (Ta), and the like.

  The stage mechanism 21 is connected to a drive mechanism (not shown) equipped with a motor, and the sample 22 placed or held on the stage mechanism 21 is moved or tilted with respect to the irradiation X-ray, or necessary. The sample 22 can be observed three-dimensionally and from all directions. Note that rotation is not always necessary for stereoscopic observation, but if there is rotation, observation can be performed with adjustment in an easy-to-see direction.

  FIG. 5 schematically shows an example of the mechanism of the stage mechanism 21. The xy stage 21A that moves the sample 22 in the horizontal direction in the xy direction, and the sample 22 is moved in the vertical direction (z axis) to increase the perspective magnification. A five-axis configuration including a z stage 21B to be changed, a rotating stage 21C that rotates the sample 22 around the X-ray beam in the field of view, and an inclined stage 21D that tilts (θ) the sample 22 with respect to the X-ray beam axis. It is a drive mechanism.

  On the other hand, FIG. 6 schematically shows an example of a cross-sectional structure of the fuel cell 30 modified for observation with the X-ray microscope of the present invention. The magnification in the vertical (thickness) direction is about 5 times that in the horizontal direction. It is enlarged to show. Metal covers 32 and 33 each having a plurality of X-ray image observation holes 32A and 33A are formed on the front and back surfaces of the fuel cell body 31 made of a layered substrate, a catalyst layer, a porous membrane, an electrolyte membrane, and the like. The inner surfaces of the metal covers 32 and 33 are made of a polyimide film (for example, Kapton (registered trademark) of DuPont) or a polyester film which has mechanical strength and is easy to transmit X-rays. Polymer films 34 and 35 are provided in layers. Accordingly, long-wavelength X-rays having a wavelength of 0.1 nm to 1.2 nm pass through the holes 32A and 33A and also through the polymer films 34 and 35, so that moisture generated from the fuel cell main body 31 is accurately observed. Can do. A beryllium plate may be used in place of the polymer films 34 and 35.

  FIG. 7 shows a state in which the fuel cell 30 is observed three-dimensionally. The fuel cell 30 is horizontally moved (xy) by the xy stage 21A of the stage mechanism 21, and the fuel cell 30 is tilted by the tilt stage 21D (see FIG. θ) indicates that stereoscopic observation at an arbitrary position is possible.

It is a characteristic view which shows an example of the attenuation characteristic of X-rays. 1 is a cross-sectional structure diagram illustrating a configuration example of an X-ray microscope according to the present invention. It is a partial cross section figure which shows the structural example of the X-ray generation part which concerns on this invention. It is a figure which shows the attenuation characteristic of long wavelength X-ray at the time of using beryllium for an X-ray transmissive window base material. It is a mechanism figure which shows the structural example of a stage mechanism. It is typical sectional drawing which shows the structural example of the fuel cell used for observation of this invention. It is a figure for demonstrating the example of observation of a fuel cell. It is sectional structure drawing which shows an example of the conventional general X-ray microscope apparatus. It is a cross-section figure showing an example of composition of an open type X-ray tube.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Open type X-ray tube 11 X-ray target 12 Target holder 13 Irradiation window 14 X-ray transmissive window base material 15 Brazing 16 X-ray generation part 20 Imaging means 21 Stage mechanism 22 Sample 23 Imaging tube 24 Metal housing 25 Sample exchange Door 26 Observation window 27 Vacuum exhaust pipe 28 Gas introduction pipe 30 Fuel cell 31 Fuel cell main body 32, 33 Metal cover 34, 35 Polymer film 100 X-ray microscope 101 Stage mechanism 102 Sample 103 Imaging tube 110 Open X-ray tube 111 X-ray target 112 Thermionic emission cathode 113 Grid 114 Anode 115 Electron lens

Claims (7)

X-ray generation means for generating an X-ray by applying an electron beam from an electron source of an electron gun to an X-ray target, and an imaging means for imaging the transmitted X-ray of the X-ray irradiated to a sample with an imaging device In the X-ray microscope, the electron beam acceleration voltage is 6 to 30 kV, the X-ray transmission window base material for vacuum-sealing the X-ray target is made of beryllium, and the thickness of the X-ray transmission window base material is A low accelerating voltage X-ray microscope characterized in that the sample chamber of the imaging means has a hermetically sealed structure, and the sample chamber is filled with a gas and a transmission image of the sample is obtained by the imaging means. apparatus. X-ray generation means for generating an X-ray by applying an electron beam from an electron source of an electron gun to an X-ray target, and an imaging means for imaging the transmitted X-ray of the X-ray irradiated to a sample with an imaging device In the X-ray microscope, the X-ray generation means generates a characteristic X-ray having a long wavelength of 0.1 nm to 1.2 nm, and the X-ray transmission window base material for vacuum-sealing the X-ray target is beryllium. The X-ray transmission window base material has a thickness of 10 to 60 μm, and the sample chamber of the imaging means has a hermetically sealed configuration, and the sample chamber is filled with gas to transmit a transmission image of the sample. A low accelerating voltage X-ray microscope. The low acceleration voltage X-ray microscope according to claim 1 or 2, wherein the gas is helium gas. The X-ray target is made of germanium, chromium, vanadium or gold, and the characteristic X-ray is the germanium, chromium or vanadium Kα ray, or the gold Mα ray. The low acceleration voltage X-ray microscope described in 1. The low acceleration voltage X-ray microscope according to any one of claims 1 to 4, wherein the sample is placed or held on a stage mechanism, and stereoscopic observation is possible by moving and tilting the sample by the stage mechanism. apparatus. A fuel cell for X-ray observation in which a metal cover having a plurality of holes is formed on the front and back of the fuel cell main body, and a beryllium plate or a polymer film is formed on the outer surface or the inner surface of the metal cover, respectively. . The fuel cell for X-ray observation according to claim 6, wherein the polymer film has mechanical strength and is easy to transmit long wavelength X-rays.