JP2004101185A - Image regulating apparatus and image regulating method of x-ray microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for simply performing image regulation of an electronic imaging system in an X-ray microscope to perform photoelectric conversion of a transmitted image generated by allowing X-ray to be incident on a sample by a photoelectric conversion surface and imaging it by the electronic imaging system as an electron image. <P>SOLUTION: A standard sample 2 is disposed at a sample position before a photoelectric conversion surface, and an electron generator 10 is disposed at the position in which the standard sample is irradiated with output beams. Image regulation of an electronic imaging system 4 is performed by using an electron image which is rapidly obtained in an imaging surface 5 by irradiating a large amount of electron beams 16 radiated from the electron generator 10 on the standard sample 2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for adjusting an image of an X-ray microscope, and in particular, an X-ray in which a transmission image generated by incidence of X-rays on a sample is photoelectrically converted on a photoelectric conversion surface and formed as an electron beam image by an electron imaging system. The present invention relates to a method and an apparatus for adjusting an image in a microscope.
[0002]
[Prior art]
An X-ray microscope can obtain a transmission image of an object by using X-rays having a short wavelength and strong transmission power as a light source.
Conventional X-ray microscopes include a projection magnifying X-ray microscope in which a sample is arranged in an X-ray luminous flux diverging from a point X-ray source and imaged by an X-ray detector arranged behind, an X-ray from the X-ray source. Imaging X-ray microscopes, which focus light on a sample with optical elements such as Fresnel zone plates and multilayer mirrors, project the transmitted X-rays onto an X-ray detector with similar optical elements, etc. is there.
[0003]
Note that Japanese Patent No. 2844703 discloses a small-sized X-ray microscope capable of facilitating living body observation, which is a major feature of the X-ray microscope. The X-ray microscope disclosed herein is a method of converting a X-ray from an X-ray source into a single color using a concave aspherical multilayer mirror condenser and condensing the X-ray on a sample, and using a phase zone plate as an imaging optical system to perform a photon counting imaging method. Is used to observe the biological sample. The publication discloses that the X-ray irradiation dose should be selected such that the maximum number of detected photons falls within the range of 25 to 200 from conditions such as not damaging the cells. It is said that a high quality X-ray image can be obtained even with a simple device.
[0004]
However, the conventional X-ray microscope has a problem that it is difficult to increase the magnification because X-rays are hardly refracted.
In order to solve this problem, there is an X-ray microscope in which an X-ray image disclosed by the present applicant in Japanese Patent Application No. 2001-235678 is converted into an electron beam image and then enlarged by an electron imaging system. The X-ray microscope is a system in which an X-ray transmission image is converted into an electron beam image on a photoelectric conversion surface, and projected on an electron beam visualization device using an electronic image magnifying device for observation. Since the electron beam is relatively easily refracted, it is possible to form a high-magnification imaging system. Therefore, the X-ray transmission image can be enlarged to a size larger than that of an optical microscope without performing complicated sample processing and image visualization processing. An X-ray transmission image of the object can be observed in detail. In particular, since the remarkable property of being able to observe even a wet sample such as a living body, which cannot be obtained by an electron microscope, can be effectively utilized, this X-ray microscope has received great expectations from research sites.
[0005]
However, in order to properly use an X-ray microscope, it is important to adjust the image such as the sharpness and magnification of the image, but it is necessary not to increase the output of the X-ray generator or to reduce the efficiency of the photoelectric conversion surface. For example, it is not possible to obtain a sufficient electron dose with the X-ray dose applied for sample observation. In order for the image to be clearly visible on the electron beam visualization device, it may be necessary to accumulate the electron beam for such a long time that, for example, several hours of exposure are required. Therefore, the adjustment of the electronic imaging system does not rely on a method of repeatedly performing a time-consuming operation of observing the imaging state after a long time and finely adjusting the apparatus based on the result by a trial and error method. This was a very time-consuming operation.
For this reason, the image adjustment work of the electron imaging system has been the main cause of lowering the efficiency of the X-ray microscope observation experiment.
[0006]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide an X-ray microscope in which a transmission image generated by incidence of X-rays on a sample is photoelectrically converted by a photoelectric conversion surface and formed as an electron beam image by an electron imaging system. An object of the present invention is to provide a method and an apparatus for easily adjusting an image of an electronic imaging system.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the image adjusting method of the X-ray microscope according to the present invention includes disposing a standard sample at a sample position in front of a photoelectric conversion surface, and disposing an electron generator at a position where an output beam irradiates the standard sample. The imaging system is adjusted by using an electron beam image obtained by irradiating an electron beam emitted from an electron generator to a standard sample.
The image adjustment may be performed by irradiating the standard sample with an electron beam and an X-ray together.
A predetermined pattern is engraved on the standard sample in the form of a grid. When the standard sample is irradiated with an electron beam, the electron beam having a predetermined pattern passing through the grid enters the electron imaging system via the photoelectric conversion surface, expands, and forms an image with the electron beam detection device. The state of the electronic imaging system can be known from the state of the image.
[0008]
The photoelectric conversion surface emits secondary electrons when electrons are incident, and this phenomenon is more efficient than photoelectric conversion. Further, since an electron generating device such as an electron gun can generate an extremely large amount of electrons as compared with an X-ray conversion electron beam, an image is quickly formed in an electron beam detecting device in, for example, several minutes to several tens of minutes. The image resulting from the adjustment can be inspected in a short time. Therefore, image adjustment can be performed very easily.
[0009]
In an X-ray microscope using laser plasma X-rays, the X-ray generation target to be irradiated by the laser is located at a position immediately before the sample, so when performing image adjustment using an electron beam, the X-ray generation target is evacuated. The electron beam from the electron generator hits the sample.
In an X-ray microscope using synchrotron radiation X-rays, an X-ray beam travels straight on an optical axis and strikes a sample, and a synchrotron or a free electron laser device that emits synchrotron radiation is moved. Since it is difficult, it is preferable that the electron beam used for image adjustment be applied to the standard sample from a direction deviated from the optical axis.
[0010]
Further, the X-ray microscope in which the X-ray beam travels straight on the optical axis and hits the sample is provided with an electron beam deflecting device in front of the photoelectric conversion surface, and the electron beam deflecting device radiates the electron beam from the electron generating device. The electron beam may be deflected to irradiate a standard sample disposed on the entire photoelectric conversion surface.
The electron beam deflecting device uses an electric field or a magnetic field to deflect an electron beam incident from an electron generating device so that the electron beam impinges on a standard sample. Since X-rays are not deflected by the electron beam deflector, there is no need to move the electron beam deflector even when using X-rays for observation of an X-ray transmission image or image adjustment.
[0011]
Further, the X-ray microscope may be provided with a mounting seat for attaching and detaching the electron generator, so that the electron generator can be used by attaching to the X-ray microscope when adjusting an image, and can be detached when unnecessary.
If the electron generator for image adjustment can be shared, the economics of operating a large number of X-ray microscopes will be improved. In addition, if a general type electron gun or the like used as a standard is used, it can be shared with an apparatus other than the X-ray microscope.
[0012]
Further, in the second image adjustment method of the present invention, a point electron source is arranged at the position of the photoelectric conversion surface instead of the photoelectric conversion surface, and an electron beam emitted from the point electron source is used to form an imaging system. The adjustment is performed.
A field emitter that emits electrons when a strong electric field is applied to silicon or a metal tip having a sharp tip can also be used as a point electron source.
If such a point light source is placed at the actual position, the image formation state in the electron detection device can be clearly grasped as a point image, and thus the image adjustment of the electron imaging system can be performed.
[0013]
In the image adjusting apparatus of the X-ray microscope of the present invention, an electron generator such as an electron gun is arranged at a position where the output beam irradiates the sample held by the sample holding device, and the standard sample is supported by the sample holding device. Then, the imaging system is adjusted by using an electron beam image obtained by irradiating the standard sample with an electron beam emitted from the electron generator.
As the electron imaging system, a magnetic field type lens can be used similarly to the electron microscope.
[0014]
In order to focus the electron beam emitted from the electron generator at the same position as the focal point of the electron beam image generated on the photoelectric conversion surface by the X-rays, the photoelectric of the electron beam emitted from the electron generator is required. It is necessary to make the energy at the conversion surface equal to the energy of the electron beam generated by X-rays. Therefore, in image adjustment using an electron beam, it is preferable to apply a voltage so that the standard sample has a negative potential having a value slightly smaller than the electron beam energy.
With the image adjusting apparatus having such a configuration, the image adjusting method of the present invention can be performed.
[0015]
When using a laser plasma X-ray generator in which an X-ray generation target irradiated by a laser is arranged in front of a sample as an X-ray generator, the X-ray generation target should be retracted from the optical axis. When performing image adjustment, it is preferable that the target be shifted before the electron beam is applied to the standard sample.
In addition, when the X-ray generation target and the photoelectron generation target are formed adjacently and integrally in a rotatable and drivable cylindrical shape, and when performing image adjustment, the X-ray generation target portion is moved in the direction of the rotation axis. The part of the target for photoelectron generation can be arranged so as to be located at the position of the optical axis.
[0016]
When a synchrotron radiation light generator such as a synchrotron or a free electron laser device is used as the X-ray generator, it is difficult to move the X-ray generator. The electron generator may be provided at a position where the light is incident from a direction different from the optical axis.
Further, an electron beam deflecting device is provided in the X-ray incident direction of the photoelectric conversion surface so that an electron beam from an electron generating device incident from a direction different from the optical axis of the X-ray is deflected to irradiate a standard sample. You can also.
[0017]
An electron generator attachment / detachment device is provided upstream of the photoelectric conversion surface of the X-ray microscope so that the electron generator can be attached and used when performing image adjustment, and the electron generator can be removed when unnecessary. be able to. By providing the attachment / detachment device, the electron generation device can be used for other devices, and therefore, the economy is excellent.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail using several examples.
[0019]
Embodiment 1
FIG. 1 is a conceptual diagram conceptually showing an X-ray microscope to which the first embodiment of the image adjusting apparatus according to the present invention is applied.
An X-ray microscope in which the image adjusting apparatus of the present embodiment is installed is configured such that an X-ray beam 1 is applied to a sample 2 arranged in front of a photoelectric conversion surface 3, and an X-ray is formed by transmitting the X-ray through the sample 2. When a transmission image is projected on a photoelectric conversion surface 3 formed of, for example, a gold Au thin film and a film of cesium iodide or antimony cesium, electrons are generated at a portion where the photoelectric conversion surface 3 receives X-rays, and X A line transmission image can be converted into an electronic image.
[0020]
When an electron beam is extracted from this electron image by an electric field and put into an electron imaging system 4 having a configuration similar to that of an electron microscope, an electron beam trajectory 6 which expands by the same operation as the electron microscope is formed and formed on the imaging surface 5. And the imaging plane 5 emits light at an intensity corresponding to the electron beam hitting each part, so that it can be presented as a visible image of an enlarged electronic image.
The operator can finely observe the X-ray transmission image of the sample 2 by the enlarged electronic image obtained on the imaging plane 5.
[0021]
The simplest imaging plane 5 is a fluorescent screen. In order to analyze the image data with a machine, it is preferable to use various electronic detectors for converting an electron beam image into an electric signal, such as a CCD element type detector.
In order to obtain a clear X-ray image, the lens intensity and the optical axis 7 of the electron imaging system 4 are adjusted so that the electron beam emitted from the photoelectric conversion surface 3 converges accurately on the imaging surface 5. Must be done.
[0022]
Various X-ray sources such as an electron beam excitation X-ray source and a discharge excitation X-ray source can be used as the X-ray generator. However, even when extremely strong synchrotron radiation having a sharp wavelength distribution is used, the amount of electrons emitted from the photoelectric conversion surface 3 is small, and the visualized image formed on the imaging surface 5 can be sufficiently evaluated. In order to obtain a bright image, it is necessary to accumulate an electron dose and it takes a considerable time.
Therefore, in the present embodiment, at the time of image adjustment, the electron generation device 10 is interposed in the optical axis of the incident X-ray to irradiate the sample surface 2 with a large amount of electron beam and accumulate electrons on the imaging surface 5. By increasing the dose and brightening the obtained image, the evaluation of the image obtained as a result of the adjustment of the electronic imaging system 4 is speeded up and the time required for the adjustment is reduced.
[0023]
Also, it is necessary to accurately grasp the magnification and the corresponding positional relationship between the actual sample and the X-ray transmission image. However, as the sample 2 used for adjustment, the size and positional relationship of each part are accurately determined. When a standard sample in which a grid having a standard pattern is cut is used, the correspondence with the X-ray image obtained on the imaging plane 5 can be easily and accurately evaluated.
[0024]
As the electron generator 10, an electron gun generally used can be used.
The electron gun includes an electron emission filament 11, an anode 12, a filament heating power supply 13, a filament bias power supply 14, and a sample bias power supply 15. The electron gun 16 emits an electron beam 16 generated by the filament 11 and accelerated by the anode 12. Incident on
[0025]
If the energy of the electron beam 16 incident from the electron gun 10 is too large, electrons passing through the photoelectric conversion surface 3 come out. Since the transmitted electron beam has a velocity at the position of the photoelectric conversion surface 3, an image is not formed at the same position as the secondary electrons having no initial velocity generated by the X-ray.
Therefore, it is necessary to adjust the bias potential of the filament 11 and the bias potential of the photoelectric conversion surface 3 so that the electron energy does not become excessive. For this reason, when the supply voltage of the filament bias power supply 14 is set to -20 kV, for example, the supply voltage of the sample bias power supply 15 is set to about -16 kV to about -19 kV, so that the difference from the filament bias is reduced to greatly accelerate electrons. Set not to give.
[0026]
With the use of the image adjusting device configured as described above, the focal position and the optical axis of the electronic imaging system 4 can be adjusted efficiently and in a very short time as compared with the related art. By associating the images, the magnification can be accurately evaluated.
[0027]
Embodiment 2
FIG. 2 is a conceptual diagram conceptually showing an X-ray microscope to which the second embodiment of the image adjusting apparatus according to the present invention is applied.
The X-ray microscope to which the present embodiment is applied is different from the first embodiment in that a laser plasma X-ray is used. The other elements are the same as those in the first embodiment, and the same reference numerals as those in FIG. 1 will be used to avoid redundant description. Although the electron gun 10 is provided with the same bias circuit as that shown in FIG. 1, this bias circuit is omitted in FIG. 2 for simplicity.
[0028]
A laser beam 21 generated using various laser generators such as a YAG laser is irradiated on an X-ray generation target 22 made of an arbitrary solid such as gold or graphite to generate plasma on the surface and emit the plasma. Thereby, a laser plasma X-ray 23 is obtained.
Since the X-ray generation target 22 is consumed with use, it is formed in a cylindrical shape, and by rotating it around an axis, the irradiation position is slightly shifted so that the laser beam always hits a new part, and the X-ray output is reduced. Has stabilized.
[0029]
Since the X-ray generation target 22 is provided close to the front surface of the sample unit 8 including the sample and the photoelectric conversion surface, when irradiating the electron beam 16 to the sample unit 8 for image adjustment, a dotted line in the figure is used. As shown, it is retracted from the optical axis 7. In this manner, the electron beam 16 from the electron gun 10 placed on or near the axis of the electron imaging system 4 is made incident on the sample unit 8 to efficiently adjust the electron imaging system 4 and evaluate the magnification. be able to.
Thus, even in the case of the second embodiment applied to the X-ray microscope using the laser plasma X-ray, the same effect as in the first embodiment can be obtained.
[0030]
Embodiment 3
FIG. 3 is a conceptual diagram conceptually showing an X-ray microscope to which a third embodiment of the image adjusting apparatus according to the present invention is applied.
In the present embodiment, the electron generator is installed at a position distant from the axis of the electron imaging system, and an electron beam for image adjustment is incident on the sample from a direction different from the X-ray incident direction. Other points are the same as those in the first embodiment. Therefore, in FIG. 3, elements having the same functions as those in FIG. 1 are denoted by the same reference numerals as those in FIG. The bias circuit of the electron gun is not shown for simplicity.
[0031]
In the image adjusting apparatus of the present embodiment, not only when the present invention is applied to an X-ray microscope using synchrotron radiation X-rays as the incident X-rays 1, but also in an X-ray microscope using laser plasma X-rays, the electron imaging system light is used. An electron gun 10 is provided outside the shaft 7 and at a position where the sample section 8 can be seen.
Since the electron gun 10 is installed outside the optical axis 7 of the electron imaging system, the sample 2 is irradiated with X-rays 1 when observing the sample and used as an X-ray microscope. To the standard sample 2 to adjust the electron imaging system 4 and evaluate the magnification. Further, when adjusting the image, the electron beam 16 and the X-ray 1 may be irradiated together to the standard sample 2 so that the electron dose may be further increased and adjusted.
As described above, in the present embodiment, since the sample observation and the image adjustment can be performed without changing the arrangement of the devices, the work efficiency is improved.
[0032]
Embodiment 4
FIG. 4 is a conceptual diagram of an X-ray microscope to which a fourth embodiment of the image adjustment device according to the present invention is applied.
In this embodiment, a means for deflecting an electron beam is provided in front of the sample part of the same X-ray microscope as the object of the above embodiment, and an electron beam incident from another direction is guided on the optical axis of the electron imaging system. The sample part is irradiated. In FIG. 4, elements having the same functions as those in the first embodiment are denoted by the same reference numerals as in FIG. It should be noted that, in the drawings, portions of the bias circuit that do not relate to the essence of the present embodiment are omitted.
[0033]
As shown in FIG. 4, the image adjusting apparatus of the present embodiment is provided with an electron beam deflecting device 30 having a pair of opposed electrodes 31 and 32 having concentric arc-shaped electrode surfaces on the front surface of the sample section 8. The electrostatic electrodes 31 and 32 are connected to an electric field generating power supply 34 and an electrode bias power supply 33, respectively, so that the former becomes the positive electrode 31 and the latter becomes the negative electrode 32. The electric field generating power supply 34 has a negative terminal connected to the negative terminal of the electrode bias power supply 33, and the positive terminal of the electrode bias power supply 33 is commonly grounded to the power supply device of the electron gun 10.
The electron gun 10 is disposed so as to emit the electron beam 16 toward the opening on the opposite side of the sample unit 8 in the space where the electrode surfaces of the electrostatic electrodes 31 and 32 face each other.
[0034]
In the space formed between the positive electrode 31 and the negative electrode 32, an electric field is generated based on the potential difference provided by the electric field generating power supply 34, and is perpendicular to the movement direction of the electron beam 16 passing between the electrode surfaces. The beam is deflected by applying uniform acceleration, emitted from the opening in the space between the electrodes, and projected onto the sample section 8.
The counter electrode 32 is provided with a through-hole 35 connected to an opening facing the sample section 8 so that the X-ray 1 traveling straight can be passed through and projected onto the sample section 8.
[0035]
When performing image adjustment using the electron beam 16, for example, when the filament potential supplied from the filament bias power supply 14 is set to −20 kV, a negative voltage of about −19 kV is set to the electrode bias power supply 33 and the electrostatic electrode 31 is set. , 32 to reduce the potential difference with respect to the potential of the electron current to slow down the electron beam. Then, even if the potential difference between the electrodes is small, the electron beam 16 is largely deflected, so that the electron beam trajectory can be bent sufficiently large at a short distance and projected onto the sample section 8.
In addition, by appropriately designing the shapes of the electrostatic electrodes 31 and 32, a function of converging the electron beam on the sample surface is provided so that the electron beam 16 can be incident on the sample portion 8 more efficiently. Can be
[0036]
In the image adjusting apparatus of the present embodiment, the installation position of the electron gun 10 can be selected relatively freely. By appropriately designing the electron beam deflecting device 30 and disposing the electron gun 10 at a position close to the sample unit 8, the electron beam can be efficiently incident on the sample.
Further, since the trajectory of the X-ray 1 is not changed by these electron beam deflecting devices 30, it is possible to observe the sample as it is or to use it together with the electron beam when adjusting the image.
In this embodiment, an electrostatic electrode is used for the electron beam deflecting device 30, but it goes without saying that a deflecting magnet may be used instead.
[0037]
In an apparatus for adjusting an image using an electron generator 10 such as an electron gun as in the apparatuses of the first to fourth embodiments, as shown in FIG. It is preferable to provide a nozzle 26 provided with an electron gun 25 and to attach the electron gun 10 housed in the airtight chamber 27 to the fitting flange 25 when necessary.
Since the electron generating device 10 such as an electron gun is not special, the nozzle 26 is used when not only owning a plurality of X-ray microscopes but also other devices sometimes using an electron gun or the like. By making the electron generating device detachable, it is possible to use one or several electron guns and the like between the image adjusting device of the X-ray microscope of the present embodiment and other devices, which is economical. It is a target.
In addition, since the electron generator can be removed except during image adjustment, the size of the device can be reduced during sample observation.
[0038]
Embodiment 5
FIG. 6 is a conceptual diagram of an X-ray microscope to which a fifth embodiment of the image adjusting apparatus according to the present invention is applied.
In the present embodiment, the sample part of the same X-ray microscope as the object of the above embodiment is configured to be retractable, and when adjusting the image, the point-like electron beam source can be arranged at the position of the sample part and adjusted. It was made possible. In FIG. 6, the same reference numerals are used for the elements having the same functions as those in each of the above-described embodiments, to avoid redundant description.
[0039]
As shown in FIG. 6, the sample section 8 is provided with a point electron source 38 such as a field emitter in addition to a set of a sample and a photoelectric conversion surface. Field emitters use the phenomenon of emitting electrons radially from the tip when a strong electric field is applied to the tip of silicon or metal having a sharp tip. The tip can be regarded as a point electron source. Note that a device in which carbon nanotubes are arranged and electrons are emitted from the tip thereof is advantageous because it can be used at a low voltage.
Since the field emitter is small, it can be easily incorporated into the sample section 8.
[0040]
In the present embodiment, the sample and the photoelectric conversion surface of the sample section 8 are arranged on the axis of the electron imaging system optical axis 7 when observing the sample. Are arranged on the optical axis 7.
The tip of a hot filament formed of barium oxide BaO or the like may be arranged as a point electron source.
When the point electron source 38 is placed at the object position and the electron imaging system is adjusted using the radially emitted electron beam, the image adjustment can be performed almost ideally. In this method, the effective magnification of the imaging system cannot be directly obtained. Therefore, when this is required, the magnification is separately measured using a standard sample or the like.
It goes without saying that the method of changing the photoelectric conversion surface of the sample unit 8 and the point electron source is not limited to parallel movement, and any method such as a method of performing position conversion by rotation can be used.
[0041]
Embodiment 6
FIG. 7 is a conceptual diagram of an X-ray microscope to which the sixth embodiment of the image adjusting apparatus according to the present invention is applied, and FIG. 8 is a perspective view of a cylindrical target used here.
This embodiment can be said to be a modification of the fifth embodiment. In an X-ray microscope using laser plasma X-rays, the photoelectric conversion target of the laser-excited electron generator is replaced with an X-ray target to obtain an electron imaging system. It can be arranged on the optical axis.
A rotating cylindrical body 41 having an X-ray target 47 and an optoelectronic target 48 formed adjacent to the cylindrical surface in the axial direction is installed on the front surface of the sample section 8.
[0042]
The X-ray target 47 is formed of gold, carbon, or the like, and emits X-rays 1 when irradiated with a laser emitted from the X-ray excitation light source 42 such as a YAG laser.
On the other hand, the optoelectronic target 48 is made of barium oxide BaO, barium carbonate BaCO 3. ₃ The electron beam 16 is generated by a photoelectric effect when a laser emitted from a photoelectron generation excitation light source 43 such as a fourth harmonic of a YAG laser or a helium cadmium HeCd lamp is applied.
[0043]
The laser light from the X-ray excitation light source 42 and the laser from the excitation light source 43 for photoelectron generation have their optical paths overlapped by a laser optical system 44 composed of a reflector, a polarizer, and the like, and are located at the same position on the surface of the rotating cylinder 41 from the same direction. It is configured to be incident. The laser light 45 enters near the intersection of the cylindrical surface of the rotating cylinder 41 and the optical axis 7 of the imaging system.
The rotating cylinder 41 rotates around the rotation axis 46 and is moved to a new part before the surface is roughened by laser irradiation, so that the stable X-ray 1 or photoelectron beam 16 is generated at any time.
Further, the rotating cylinder 41 moves in the axial direction of the rotating shaft 46.
[0044]
At the time of sample observation, the X-ray excitation light source 42 is operated to observe an X-ray transmission image using the X-rays 1 from the X-ray target 47. At the time of image adjustment, the rotating cylinder 41 is moved in the axial direction and the The excitation light source 43 for generating photoelectrons is operated after the portion of the target 48 comes to the position where the laser beam 45 hits, and the image adjustment of the electron imaging system is performed using the electron beam 16 emitted from the photoelectron target 48.
The image adjusting apparatus according to the present embodiment has a greater degree of freedom in the arrangement of devices and can be configured with small modifications, so that the cost can be reduced. Further, switching work for image adjustment is also easy.
[0045]
In each of the above embodiments, it is preferable to use a magnetic field type lens formed by an electromagnet as shown in FIG. 9 for an electron imaging system for enlarging and forming a photoelectron image emitted from a sample.
FIG. 9 shows an example of the arrangement of the electron imaging system 4 using the magnetic lenses 51, 52, and 53 in the upper diagram, and changes in the magnetic field intensity Bz along the optical axis 7 of the imaging system in the lower diagram. .
The magnetic field strength Bz generates a strong positive magnetic field at the objective lens formed in the gap of the electromagnet 51, converges the emitted electron flux, and expands it in the opposite phase direction. The electron flux enters the projection lens, is further enlarged, and is projected on the image forming plane 5. The projection lens is composed of two electromagnets 52 and 53, and is actually converged and expanded by a two-stage lens having a magnetic field strength in the opposite direction as shown in the lower diagram.
[0046]
Since the magnetic lens rotates the electron trajectory according to the strength of the magnetic field, the rotation of the image is prevented by applying a magnetic field in the opposite direction. If the magnetic field strength is changed as a lens parameter after the image is adjusted so that the image does not rotate, the image rotates. Therefore, this is canceled by the magnetic field in the opposite direction to prevent the image from rotating even under new conditions. be able to.
In addition, when a small-diameter aperture is inserted into the optical axis, the aberration is improved. However, in the case of an electrostatic imaging system, the aperture cannot be used because the electric field is disturbed if the aperture is present. On the other hand, in an electron imaging system using a magnetic lens, aberration can be further improved by using an appropriate aperture.
[0047]
【The invention's effect】
As described above, the image adjustment apparatus and the image adjustment method in the X-ray microscope according to the present invention increase the electron beam in the electron imaging system and quickly clarify the image on the image formation plane. Time and effort are greatly reduced.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram illustrating a configuration of an image adjusting device of an X-ray microscope according to a first embodiment of the present invention.
FIG. 2 is a conceptual diagram illustrating a configuration of an image adjusting apparatus of an X-ray microscope according to a second embodiment of the present invention.
FIG. 3 is a conceptual diagram showing a configuration of an image adjusting apparatus of an X-ray microscope according to a third embodiment of the present invention.
FIG. 4 is a conceptual diagram illustrating a configuration of an image adjusting apparatus of an X-ray microscope according to a fourth embodiment of the present invention.
FIG. 5 is a conceptual diagram showing a configuration in which an electron generating device is made detachable in each embodiment of the present invention.
FIG. 6 is a conceptual diagram illustrating a configuration of an image adjusting apparatus of an X-ray microscope according to a fifth embodiment of the present invention.
FIG. 7 is a conceptual diagram showing the configuration of an image adjusting device of an X-ray microscope according to a sixth embodiment of the present invention.
FIG. 8 is a perspective view of a cylindrical target used in a sixth embodiment.
FIG. 9 is a conceptual diagram showing a mode in which an electronic imaging system is formed by a magnetic lens in each embodiment of the present invention.
[Explanation of symbols]
1 X-ray
2 samples, standard samples
3 Photoelectric conversion surface
4 electron imaging system
5 Image plane
6. Electron orbit
7. Optical axis of imaging system
8 Sample section
9 X-ray microscope chamber
10. Electron generator, electron gun
11 electron emission filament
12 Anode
13 Filament heating power supply
14 Filament bias power supply
15 Sample bias power supply
16 electron beam
21 Laser light
22 X-ray generation target
23 Laser Plasma X-ray
25 Connecting flange
26 nozzles
27 Airtight chamber
30 Electron beam deflector
31 Positive electrode
32 negative electrode
33 Electrode bias power supply
34 Power supply for electric field generation
35 through hole
38 point electron source
41 rotating cylinder
42 X-ray excitation light source
43 Excitation light source for photoelectron generation
44 Laser Optical System
45 Laser light
46 rotation axis
47 X-ray target
48 Optoelectronic Target
51 Electromagnet for objective lens
52,53 Electromagnet for projection lens

Claims (14)

In an X-ray microscope in which a transmission image generated by incidence of X-rays on a sample is photoelectrically converted by a photoelectric conversion surface and formed as an electron beam image by an electron imaging system, a standard sample is disposed at a sample position before the photoelectric conversion surface. An electron generator is arranged at a position where the output beam irradiates the standard sample, and an image forming system is formed by using an electron beam image obtained by irradiating the standard sample with an electron beam emitted from the electron generator. A method for adjusting an image of an X-ray microscope. The X-rays are laser plasma X-rays, an X-ray microscope in which an X-ray generation target irradiated by a laser is arranged in front of the sample, and when adjusting the imaging system, the X-ray generation 2. The method according to claim 1, wherein the target is retracted from the optical axis. 2. The X-ray according to claim 1, wherein the X-ray is synchrotron radiation, and the electron generator is disposed so that the electron beam is incident from a direction different from an optical axis of the X-ray. How to adjust the microscope image. 2. An X-ray microscope image adjustment apparatus according to claim 1, wherein an electron beam deflecting device is provided in front of the photoelectric conversion surface, and the electron beam emitted from the electron generating device is deflected to irradiate the standard sample. Method. The image adjusting method for an X-ray microscope according to any one of claims 1 to 4, wherein the electron generator is used by being attached to the X-ray microscope when adjusting an image. The X-ray according to any one of claims 1 to 5, wherein, in addition to the electron beam, the X-ray from the X-ray generator is incident on the standard sample to adjust an image of an imaging system. How to adjust the microscope image. In an X-ray microscope in which a transmission image generated by incidence of X-rays on a sample is photoelectrically converted by a photoelectric conversion surface and formed as an electron beam image by an electron imaging system, a point electron source is replaced by the photoelectric conversion surface instead of the photoelectric conversion surface. An image adjustment method for an X-ray microscope, comprising: arranging an imaging system using an electron beam emitted from the point electron source at a position of a conversion surface. An X-ray generator, a sample holding device, a photoelectric conversion surface, and an electron imaging system are provided. A transmission image generated when X-rays enter the sample is photoelectrically converted by the photoelectric conversion surface and formed as an electron beam image by the electron imaging system. In an X-ray microscope to be imaged, the electron generator is arranged at a position where an output beam irradiates a sample gripped by the sample gripper, a standard sample is supported by the sample gripper, and emitted from the electron generator. An image adjusting apparatus for an X-ray microscope, wherein an image forming system is adjusted using an electron beam image obtained by irradiating the standard sample with an electron beam. The X-ray generation device is a laser plasma X-ray generation device in which an X-ray generation target to be irradiated by a laser is arranged in front of the sample. When performing the image adjustment, the X-ray generation target is retracted from the optical axis. 9. The image adjusting device for an X-ray microscope according to claim 8, wherein the image adjusting device is capable of performing the adjustment. The X-ray generation target is formed in a cylindrical shape that can be driven to rotate adjacent to and integrated with the target for photoelectron generation. When performing the image adjustment, the X-ray generation target is moved in the direction of the rotation axis to move the X-ray generation target. 10. The image adjusting apparatus for an X-ray microscope according to claim 9, wherein a portion of the target for generating photoelectrons is arranged at the position of the optical axis. The X-ray generation device is a synchrotron radiation light generation device, wherein the electron generation device is arranged such that the electron beam is incident from a direction different from the optical axis of the X-ray. An image adjusting device for an X-ray microscope according to claim 8. 9. An X-ray microscope according to claim 8, wherein an electron beam deflector is provided in front of the photoelectric conversion surface, and the electron beam emitted from the electron generator is deflected to irradiate the standard sample. apparatus. The X-ray according to any one of claims 8 to 12, further comprising a detachable device for the electron generator, wherein the electron generator can be used by attaching to the X-ray microscope when performing image adjustment. Image adjustment device for microscope. 14. The apparatus according to claim 8, wherein the imaging system uses a magnetic lens.

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