JPH085798A - X-ray microscope - Google Patents

Abstract

PURPOSE:To enable the focusing in an X-ray optical system by using the relative relation of refractive indexes to X rays and visible rays in a sample container to calculate the optical distance in X rays on the basis of that in visible rays and control a displacement mechanism. CONSTITUTION:Firstly, in a visible optical system 200, the position of an X-ray penetrating window 10b in a sample container 4 is measured with a prescribed measuring coordinates system. Secondly, a focus is adjusted on the position where a sample is to be observed and an input device 23b is operated to measure the position of an X-ray penetrating window 10b with a measuring means in a coordinates system. From the two measured positions of an X-ray penetrating window 10b, the optical distance in visible rays in the sample container 4 is measured. Subsequently, an arithmetic means 23 calculates the optical distance in X rays on the basis of the optical distance in visible rays. Then, a controller 23a adjusts the position of the sample container 4 by controlling a sample stage 24 to focus the X-ray optical system 100 on the point where the sample 12 is to be observed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray microscope for obtaining an X-ray magnified image of a sample to be measured, and more particularly to an X-ray microscope having optical observation means.

[0002]

2. Description of the Related Art In the fields of medicine and biology, which are rapidly advancing in recent years, ordinary visible light (wavelength λ = about 400 nm to 8 nm) is used.
00nm) has a higher resolution than a microscope using a living sample (hereinafter referred to as a biological sample), for example, a cell,
The demand for a high-resolution microscope capable of clearly observing bacteria, sperm, chromosomes, mitochondria, flagella, etc. is increasing day by day.

The reason for this is that conventional high resolution electron microscopes could not see such biological samples without pretreatment. Therefore, an X-ray microscope using soft X-rays with a wavelength λ = 2 to 5 nm instead of visible light in order to enable observation in a living state without pretreatment of such a biological sample. Are being considered and are being specifically developed.

A conventional X-ray microscope is equipped with an optical system, for example, as shown in FIG. That is, the conventional X
In the line microscope, the X-rays emitted from the X-ray generator 1 are condensed by the X-ray illumination optical system 3 and irradiated on the sample capsule 4. Then, the X-ray transmitted through the sample capsule 4 is
The X-ray magnifying optical system 5 forms an X-ray image of the sample on the X-ray imaging device 7. The optical path length from the X-ray generator 1 to the X-ray imaging device 7 is, for example, about 2 m.

The above-mentioned structure is usually housed in a vacuum container 6, and the vacuum container 6 is held in vacuum by an exhaust device 2.

In the soft X-ray wavelength region used in the conventional X-ray microscope based on such a structure, the absorption of X-rays by the substance is shown in FIG. 6 depending on the wavelength of the X-rays, the atomic number of the substance, and the like. It changes as shown. Generally, the longer the X-ray wavelength, the easier the absorption, and the larger the atomic number of the substance, the easier the absorption. In particular, in the X-ray wavelength range of 2.3 to 4.4 nm, oxygen-containing water has a higher transmittance than organic matter containing carbon such as protein.

That is, in this wavelength range, since the difference in absorption rate between water and protein is large, contrast is provided by the ratio of these components, and the cell structure placed in water without staining becomes Can be clearly identified. This wavelength range is called a water window and is a very useful wavelength range for a microscope used for observing a biological sample.

As described above, the X-ray microscope has
If 5 nm X-rays are used, organisms have various characteristics such as high resolution and no staining.

On the other hand, the photon energy of X-rays used for observation is larger by one digit or more than the photon energy of visible light. Therefore, as a microscope, a high resolution can be obtained, but since energy per photon is large, the sample is easily damaged.

However, in the conventional microscope observation method,
While irradiating a biological sample with X-rays, we are looking for the part to be observed. This is undesirable for biological samples as it causes X-ray radiation damage.

Therefore, in order to bring the portion to be observed into the field of view of the X-ray microscope in advance, an optical observation means (optical microscope) for visible light is simultaneously arranged on the optical axis of the X-ray microscope, and A method and an apparatus for performing preliminary observation by a dynamic observation means have been proposed in Japanese Patent Application Laid-Open No. 4-346100 and are actually being used.

In this method and apparatus, the field of view, the focal position, etc. of the optical observation means are matched with those of the X-ray microscope in advance or corresponded thereto. Furthermore, when the optical observation means is switched to the X-ray observation means, the area that has been optically observed can be observed as it is even with X-rays.

Therefore, the X-rays to be irradiated can be minimized before the portion of the biological sample to be observed is determined, and as a result, the observation time can be shortened.

[0014]

However, the following problems have been pointed out in the configuration of the X-ray microscope of the above example.

X-ray microscope resolution δ and depth of focus DOF
Is the wavelength of the X-ray used and the NA of the X-ray objective lens, and is determined by the following relational expression.

Δ = 0.61λ / NA ……………………………………………… (1) DOF = 2λ / NA ² ……………………………… (2) For example, assuming that the NA of the X-ray objective lens is 0.1 and the wavelength of the X-ray is 3 nm, δ is calculated from the above equations (1) and (2).
0.009 μm and DOF are 0.6 μm.

That is, a high-resolution X-ray microscope has a shallow depth of focus, and the shift of the focus greatly affects the image. For this reason, in such an X-ray microscope, it is very important to perform accurate focusing, and adjustment thereof often takes time.

In the conventional X-ray microscope as described above, the X-rays which are irradiated on the sample such as a living organism during such focusing.
In order to reduce the amount of rays as much as possible, an X-ray microscope is provided with an optical observation means, and prior to observation with X-rays,
Positioning and focusing of the sample are performed by the optical observation means.

However, when attempting to observe a biological sample in water by an optical observation means, the refractive index with visible light is larger than 1 for both water and the biological sample. For example, suppose that the sample is in water and there is a sample to be observed at a depth of 10 μm from the surface of the sample container. Here, when L is an optical distance with visible light, nL is 10 μm, and the refractive index n of water is about 1.33. Therefore, L = 10 μm / 1.3
3 = 7.5 μm. This means that the sample looks at a depth of 7.5 μm by optical observation means. As a result, even if the sample is focused by the optical observation means, the focus is on a position shallower than the actual position of the sample.

On the other hand, in X-ray observation, almost all substances including water can be regarded as having a refractive index of 1.
Therefore, the sample having the same arrangement as described above can be seen at a position having a depth of 10 μm, which is the same as the actual depth, when viewed with an X-ray microscope.
That is, the focal position by the X-ray and that by the optical observation means are displaced by 2.5 μm in the depth direction.

The DOF of the optical observation means is NA =
When 0.95 and λ = 500 nm, it is 1.1 μm. This DOF value is almost the same as that of the X-ray microscope.

That is, as in the prior art, even if the focus position is adjusted to the sample to be observed by the optical observation means prior to the observation of the X-ray, the difference in refractive index between visible light and X-ray is obtained. Therefore, in the end, there is a problem that the focus must be re-adjusted for the observation with X-rays. Further, as a result, there is a problem that the sample is irradiated with X-rays for focusing, and the sample is damaged.

The present invention relates to an X-ray microscope including a visible light optical system and an X-ray optical system, and uses the X-ray optical system based on the position to be observed of the sample focused and specified by the visible light optical system. It is an object of the present invention to provide an X-ray microscope capable of focusing on the position to be observed.

[0024]

The above object is to provide an X-ray optical system including an X-ray optical system for obtaining an X-ray image of a sample contained in a sample container and a visible light optical system for obtaining a visible light image of the sample. In a microscope, a sample container displacement mechanism that displaces the sample container along at least the respective optical axis directions of the X-ray optical system and the visible light optical system and a visible light optical system from a predetermined measurement origin. Visible light observation position measuring means for measuring the optical distance with visible light to the position to be observed of the focused sample, the measured optical distance with the visible light, and the sample which is obtained in advance, An X-ray for calculating the optical distance of the X-ray from the origin to the position to be observed from the relative relationship of the refractive index with respect to the visible light and the X-ray used for observation in the container. Based on the observation position calculation means and the calculation result, change the sample container By controlling the mechanism, the focal position by the X-ray optical system is achieved by X-ray microscope, characterized by a control means for displacing the sample container so as to coincide with the position to be the observation.

[0025]

The operation of the X-ray microscope according to the present invention to achieve the above object will be described with reference to FIG.

When observing a biological sample such as a cell with an X-ray microscope, a member transparent to X-rays and visible light used for observation, for example, an X-ray transmission window 10 made of Si ₃ N ₄ is used.
As shown in FIG. 2A, a biological sample 12 such as a cell is sandwiched between sample containers 4 having a and 10b. Further, the medium 1 for holding the biological sample 12 in the sample container 4
1, for example filled with water.

As described above, the X-ray used for observation causes radiation damage and is naturally harmful to the biological sample 12 to be observed. Therefore, when observing with X-ray, the X-ray irradiation dose should be minimized. It is desirable to observe with minimal damage.

Therefore, in the present invention, the X-ray optical axis of the X-ray optical system, which is the means for observing with X-rays, and the visible light optical system, which is the optical observing means capable of arranging the optical axis coaxially,
The region to be observed is specified in advance and brought into the visual field of the X-ray optical system.

However, as described above, even if the optical observation means is focused on the portion to be viewed, the focus position is incident on the inside of the sample container 4 and refraction of visible light in the medium 11 causes The position is different from the focal position of the 12 X-rays.

The shift between the focal position obtained by the observation with visible light and the focal position by X-ray has the following relationship.

For example, as shown in FIG. 2B, the position of the X-ray transmission window 10a of the sample container 4 is W, the observation position of the sample 12 obtained by focusing with the optical observation means is S1,
Assuming that the refractive index of the medium 11 filled in the sample container 4 with respect to visible light used for observation is n1 and the observation position of the actual sample is S, the visible light used for observation is refracted in the sample container 4. Therefore, the following relational expression holds.
The visible light used for observation is assumed to be incident from the bottom of the figure.

S−W = n1 (S1−W) …………………………………… (3) Here, W, S1, and S are for observation rather than the sample container 4. It shall be measured along the optical axis from an origin located at a predetermined position on the side of the source of visible light used.

Further, as shown in FIG. 2A, the observation position of the sample 12 corresponding to the observation position S of the sample 12 obtained by focusing by X-ray observation is S2, which is used for observation. When the refractive index of the medium 11 with respect to X-rays is n2, the following relational expression holds.

S−W = n2 (S2−W) …………………………………… (4) Here, the refractive index of the medium 11 for X-rays is almost 1 for any substance. Therefore, the observation position S2 to be focused by the X-ray observation may be regarded as the actual observation position S.

Therefore, from the expressions (3) and (4), the position W of the X-ray transmission window 10a and the observation position S1 by visible light are determined.
If it is possible to know the refractive index n1 for visible light, the observation position S of the sample, that is, the observation position S2 at which the focus should be adjusted in X-ray observation can be calculated.

Alternatively, with the position W of the X-ray transmission window 10a as a reference point, the distance from the position W to the observation position S1 by visible light, that is, the optical distance of visible light in the sample container 4 and the visible light If the refractive index n1 can be known, the distance from the position W to the observation position S2 (≈S) by the X-ray, that is, the optical distance of the X-ray in the sample container 4 can be obtained.

Specifically, first, the visible light optical distance from the predetermined measurement origin to the position of the sample 12 to be observed is measured by the visible light observation position measuring means. Here, the optical distance is specifically the distance from the origin for measurement to a reference point on the sample container 4, for example, a point on the X-ray transmission window 10a, and observation from the reference point. The optical distance in the sample container 4 up to the power position can be divided. However, since the optical distance from the origin to the reference point is located in vacuum, there is no change in the refractive index with respect to X-rays and visible light. Therefore, only the optical distance in the sample container 4 is considered.

In the visible light optical system, in order to change the focusing position, for example, the operator performs an operation corresponding to the displacement amount on the operation receiving means, and in response to the operation, the control means sets the sample The operation of the container displacement mechanism is controlled to displace the sample container 4 and change the focus position in the visible light optical system.

Further, the operation receiving means receives, for example, an operation relating to the determination of the in-focus position by the operator, and correspondingly, the visible light observing position measuring means causes the visible light observing position measuring means to observe the position of the sample to be observed. You can know. With such a configuration, for example, the optical distance with visible light can be measured as follows.

That is, the visible light optical system focuses on a predetermined reference point on the X-ray transmission window 10a, and then the visible light optical system focuses on the position S1 of the sample 12 to be observed. The optical distance of the visible light in the sample container 4 is measured by detecting the amount of displacement of the sample container 4 displaced along with this operation on the optical axis of the visible light optical system.

The X-ray observation position calculating means calculates the optical distance of X-rays used for observation based on the measured optical distance with visible light. In this calculation, for example, the relative relationship between the X-ray and the visible light in the sample container is used. Here, as described above, the refractive index n of the medium 11 filled in the sample container 4 is
1 is preferably measured in advance, but in the case of an underwater sample, the refractive index of water may be 1.33.

Finally, from the visible light optical system to the X-ray optical system,
While switching the observation means, the control means controls the obtained X
The X-ray optical system controls the sample container displacement mechanism based on the optical distance in the sample container 4 as a line and the distance from the origin for the measurement with visible light to the reference point on the sample container. The sample container is brought to the position S (S2) to be focused at.

In this state, if an image is picked up by X-rays, the position to be observed specified by the visible light optical system is focused and a good X-ray image can be taken. Therefore, the present invention overcomes the problem that the sample 12 must be exposed to extra X-rays in order to refocus.

[0044]

EXAMPLE A first example of an X-ray microscope according to the present invention will be described.
This will be described with reference to FIGS. 1 and 7.

As shown in FIG. 1, the X-ray microscope of this embodiment comprises a sample container 4 containing a sample 12 and a medium 11, an X-ray optical system 100 for observing the sample 12, and a visible light optical system. The system 200, the measuring means 400 for measuring the position of the sample container 4, the measurement result from the measuring means 400, and the observation position S1 specified by the visible light optical system 200 (see FIG. 2). Observation position S corresponding to
And a calculation means 23 for calculating 2.

In the present embodiment, the sample stage 24 further supports the sample container 4 and displaces the position thereof in the optical axis 300 direction of the X-ray and in a plane orthogonal to the axis 300.
And a control device 23a for controlling the operation of the sample stage 24 based on the result obtained by the calculation means 23, an operation for the operation amount of the sample stage 24 relating to the focusing operation, and the determination of a specific focusing position. An input device 23b that receives an operation related to.

Here, the specific in-focus position is a position that the operator desires to focus, that is, a position to be specified, when observing. In the present embodiment, as a position to be observed (corresponding to S1) of the sample 12 and a reference point (corresponding to W) of the optical distance with visible light, which is focused during the observation of the operator. Indicates the determined position.

In this embodiment, further, as shown in FIG.
A switching means 401 for switching the X-ray optical system 100 and the visible light optical system 200 to each other, a vacuum container 6 for housing at least the X-ray optical system 100, the visible light optical system 200, the sample stage 24, and the sample container 4, and a vacuum. An exhaust device 2 for evacuating the inside of the container 6 to maintain the state,
The display device 8 displays the image of the sample obtained by each of the optical systems 100 and 200.

The control device 23a controls the operation of the sample stage 24 in response to a command relating to focusing input via the input device 23b. Further, based on the X-ray observation position S2 obtained by the computing unit 23, the sample container 4 is placed so that the X-ray optical system 100 focuses on the observation position of the sample 12 specified by the visible light optical system 200. The operation of the sample stage 24 is controlled so that it is positioned. Further, the control device 23a controls the switching unit 401 based on an external command to switch the optical system used for observation.

Here, the control device 23a and the computing means 2
3 is implemented by, for example, a computer including a CPU and a memory. A keypad or a keyboard can be used as the input device 23b.

The switching means 401 is, for example, the optical axis 30.
It has a moving member that moves in the axial direction orthogonal to 0 and an actuator that drives the moving member. On the moving member of the means 401, corresponding optical elements in the two optical systems 100 and 200, for example, the X-ray magnifying system 5 and the visible light magnifying lens 27.
And are mounted side by side along the direction of movement.

According to this structure, the moving member is displaced in the direction orthogonal to the optical axis 300 in accordance with the input switching command, and it becomes possible to switch between the optical element units of the two optical systems. By applying it to the element, the visible light optical system 200 and the X-ray optical system 100 can be switched.

X-ray optical system 100 and visible light optical system 20
0 is arranged so as to be switchable by the switching means 401 in a state where the fields of view and the focal points thereof are the same or correspond to each other as a whole.

The X-ray optical system 100 includes an X-ray generator 1 for generating X-rays, an X-ray illumination system 3 for condensing the generated X-rays at a predetermined focus position, and an X-ray illumination system 3 for passing the focus position. An X-ray magnifying optical system 5 for converging the expanding X-ray illumination light and forming an X-ray image of a portion of the sample 12 located at the focal position on a predetermined position, and the formed X-ray image. And an X-ray imaging device 7 for converting the received image signal.

The visible light optical system 200 includes a visible light source 25 for generating visible light, a visible light illumination system lens 26 for condensing the generated visible light at a predetermined focus position, and a light passing through the focus position. A visible light objective lens 27 that collects the expanding visible light illumination light and forms a visible light image of a portion of the sample 12 located at the focal position at a predetermined position, and an image that receives the formed visible light image. Visible light imaging device 28 for converting into a signal
Have and.

As described in the section of the above-mentioned action, the calculating means 23 is from the position W of the sample container 4 measured by the measuring means 400 to the observing position S1 by visible light according to the equations (3) and (4). Of the focal point by the visible light optical system 200 and the X-ray optical system 100 by using the distance and the refraction index n1 that has been input in advance, from the position W to the observation position S2 by X-ray. To calculate the distance.

The sample stage 24 has a displacement member that holds the sample container 4 and an actuator that displaces the displacement member in predetermined XYZ axis directions. Further, the sample stage 24 is provided with a hole 24a for passing visible light and X-rays used for observation, and the visible light and X-rays condensed by each illumination optical system 3 or 26 are converted into a sample container. 4 is directly irradiated.

In the present embodiment, the measuring means 400 accepts an operation command for determining the reference point on the sample container 4 and the position of the sample to be observed, which is specified by the operator via the input device 23b. The measuring means 400 further includes
Based on this operation command, the X-ray transmission window 10b (position W) of the sample container 4 at the time of observation by the visible light optical system 200.
And the position of the part of the sample 12 to be observed (observation position S1), and the displacement distance of the sample container 4 associated with the movement between these two positions is determined by the optical distance in the sample container 4. It is measured as the target distance.

In this embodiment, as shown in FIG. 1, X-rays and visible rays are irradiated from the lower side of the figure, and the sample container 4 has its X-ray transmission window 10a in the sample stage 24.
It is placed so that it touches. Therefore, with the configuration of the present embodiment, it is difficult to detect the position of the X-ray transmission window 10a, as described in the section of the above operation. Therefore, in the present embodiment, the position of the X-ray transmission window 10b is measured by the measuring means 400, and the position and the distance between the two transmission windows 10a and 10b obtained by measurement in advance are used for calculation. It is assumed that the position W is obtained by the means 23.

Specifically, the measuring means 400 is a displacement measuring mechanism of an optical lever type and has a good parallelism, for example, a laser light source 21 for irradiating a predetermined position of the X-ray transmission window 10b with a laser light. , The source 21 and the transmission window 10b are arranged so as to have a predetermined relative positional relationship.
For example, the position detector 22 includes a one-dimensional line CCD that detects the laser light reflected by b and measures the detection position that changes with the position displacement of the transmission window 10b.

According to this measuring means 400, the sample container 4
Also, the position of the sample container 4 and its displacement can be measured without physically interfering with the sample stage 24, the X-ray optical system 100 arranged around it, or the visible light optical system 200.

The operation of this embodiment will be described.

In this example, first, the sample 1 by visible light was used.
2) The position to be observed is specified. Specifically, the control device 23a and the switching unit 4 are based on the operator's command.
01, the optical system used for observation is set to the visible light optical system 200.
Switch to. Further, according to the instruction of the operator, the position of the sample stage 24 is set to the input device 23b and the control device 23.
Control via a.

The operator adjusts the focus of the visible light optical system 200 on the X-ray transmission window 10b of the sample container 4,
The position of the sample container 4 is adjusted by displacing the sample stage 24. Further, when the operator focuses on a predetermined position on the transmission window 10b, the operator performs a predetermined operation on the input device 23b to set that position as a reference point on the sample container 4.

The input device 23b responds to this operation by
The signal indicating the determination of the reference point on the sample container 4 is measured by the measuring means 40.
Output to 0. The measuring means 400 accepts this and
The position of the X-ray transmission window 10b of the sample container 4 at that time is measured by a predetermined measurement coordinate system in which a measurement origin is set. The position measured here is the so-called
It is an absolute position and indicates the optical distance from the origin for measurement to the reference point provided on the sample container 4.

Next, the operator focuses on the position of the sample 12 to be observed and performs a predetermined operation on the input device 23b so as to make that position the position to be observed. In response to this operation, a signal indicating the determination of the observation position is output to the measuring means 400. Measuring means 400
Accepts this, and X of the sample container 4 at that time
The position of the line transmission window 10b is measured by the above coordinate system.

The measuring means 400 measures the displacement distance of the sample container 4, that is, the optical distance of visible light in the sample container 4 from the positions of the two X-ray transmission windows 10b thus measured. To do.

Here, the measuring means 400 is configured to measure the displacement distance. For example, the measuring means 400 outputs the two measured positions of the X-ray transmission window 10b to the calculating means 23, and the calculating means 23. The displacement distance may be calculated.

Next, the calculating means 23 calculates the X-rays from the equations (3) and (4) described in the above section on the basis of the optical distance with visible light obtained as described above. Calculate the optical distance of.

In this state, the control device 23a and the switching means 401 switch the optical system used for observation to the X-ray optical system 100. The switching here is based on the operator's instruction, and is based on the control device 23a and the switching means 40.
However, the switching operation may be automatically performed after the operator determines the position to be observed.

In the present embodiment, the focal position of the X-ray optical system 100 and the focal position of the visible light optical system 200 are preliminarily matched or correspond to each other. Control device 23a
Is based on the optical distance of the X-ray in the sample container 4 obtained by the calculating means 23 and the optical distance from the origin for measurement to the reference point on the sample container 4 The displacement operation of the sample stage 24 is controlled to adjust the position of the sample container 4 so that the X-ray optical system is focused on the power position.

In this state, soft X-rays are generated from the X-ray generator 1 and imaged by the X-ray image pickup device 7, so that good X-rays focused on the observation position specified by the visible light optical system 200 can be obtained. You can get a statue.

Further, even if the focal positions of the X-ray optical system 100 and the visible light optical system 200 do not match, the relative distance between these focal positions is checked in advance, and the controller 23a uses this to check the relative distance. The configuration is such that the displacement amount of the sample stage 24 is corrected.

According to this embodiment, from the relative position of the sample container 4 to be observed specified by the visible light optical system 200 and the relative index of refraction, the X-ray optical system is moved to the position to be observed. The system 100 can be focused. For this reason,
There is no need to irradiate X-rays for focusing when observing with the X-ray optical system 100.

In this embodiment, the optical systems 100 and 200 are used.
Although the optical system used for observation is switched by changing the position of, the present invention is not limited to this. In the present invention, as long as the sample can be observed by the two optical systems, the arrangement of the two optical systems and the switching method thereof are not limited, and for example, the sample container 4, the sample stage 24, and the measuring means. The configuration may be such that 400 moves between two optical systems.

Further, in the present embodiment, the difference between the optical distance in visible light and the optical distance in X-ray depends on the sample container 4
Although it is assumed that the refractive index is different depending on the medium 11 inside, strictly speaking, in addition to the influence of the medium 11, the refraction at the X-ray transmission window 10a and the refraction inside the sample 12 also have an influence. However, the X-ray transmission window 10a can be made very thin and can be almost ignored. Further, since the constituent members of the X-ray transmission window 10a and the thickness thereof can be known in advance, the influence thereof is previously obtained based on them, and the observation position by the X-ray obtained as described above is obtained. S2 may be corrected.

Regarding the refraction in the sample 12, the influence thereof can be ignored unless the sample 12 is physically larger than the medium 11. Furthermore, the sample 12
If it is an organism such as a cell, considering its components,
The optical properties can be assumed to be the same as the medium 11 (eg water). Alternatively, the refractive index of the sample 12 with respect to visible light used for observation may be directly obtained in advance and used.

Further, in order to consider the refractive indexes of the X-ray transmission window 10a and the sample 12, the X-ray transmission window 10a, the medium 11 and the sample 12 are all regarded as one member in advance, and this member is used. It is also possible to obtain an equivalent refractive index for visible light in the above and use that refractive index instead of n1.

Such an equivalent refractive index can be obtained as follows, for example. That is, the upper surface of the X-ray transmission window 10a close to the light source and the other X-ray transmission window 1
Focusing on the upper surface facing the inside of the sample container 4 of 0b,
Measure the distance between them. Here, the obtained distance is an optical distance by visible light, and if the sample 12 and the medium 11 are contained in the sample container 4, the X-ray transmission window 10a, the medium 11, and the sample 12 All impacts are included. This distance is the distance between the X-ray transmission windows and is known in advance. Therefore, by comparing this actual distance with the obtained optical distance, the above equivalent refractive index is obtained.

A second embodiment of the X-ray microscope to which the present invention is applied will be described with reference to FIG.

As shown in FIG. 3, this embodiment basically has the same structure and operation as those of the first embodiment, but is different only in the concrete structure of the measuring means. Here, among the configurations shown in FIG.
The same reference numerals are given and the description thereof is omitted.

The measuring means of this embodiment is the X-ray transmission window 10b.
It has a well-known contact type position sensor 31 for measuring As the sensor 31, for example, what is called a capacitance type contact displacement meter or a micro sense can be used. The sensor 31 includes a displacement portion 31b which is brought into contact with a displacement target 31b of a measurement object and changes with displacement of the target object, and a capacitor (not shown) whose gap interval is displaced in association with the displacement portion 31b. The displacement amount of the object is measured by converting the capacitance change of the capacitor due to displacement of the gap distance of the capacitor into the displacement amount and measuring the displacement amount.

In this embodiment, the position of the X-ray transmission window 10b is measured by using the contact type position sensor 31, and the visible light optical system 200 and the X-ray optical system 10 are processed in the same manner as in the first embodiment.
By correcting the deviation of the focus position from 0, the optical distance in visible light is converted into that of X-rays, and the focus of the X-ray optical system 100 reaches the position specified by the visible light optical system 200. You can make it fit.

According to this embodiment, since the contact-type position sensor 31 is used as the measuring means, the sensor 31 can be easily arranged and the adjustment after that is easier than the non-contact-type measuring means of the first embodiment. Is also easy.

A third embodiment of the X-ray microscope according to the present invention will be described with reference to FIG.

This embodiment basically has the same structure and operation as those of the first embodiment, but is different only in the concrete structures of the sample container 4 and the measuring means. In FIG.
An example of the arrangement of the measuring means, the sample container 4, and the sample stage 24 in this embodiment is shown. Here, of the configurations shown in FIG. 4, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

In this embodiment, the sample container 4 has an X-ray transmission window container 41 for fixing the X-ray transmission windows 10a and 10b. Further, the sample stage 24 has a stage position measuring device 42 for measuring the stage position, for example, including a linear scale.

In the present embodiment, the position of the sample container 4 is measured by the stage position measuring device 42, and in the same manner as in the first embodiment, the shift of the focal position between the visible light optical system 200 and the X-ray optical system 100 is detected. By the correction, the X-ray optical system 100 can be focused on the position specified by the visible light optical system 200.

According to this embodiment, the displacement amount of the sample stage 24 can be measured instead of measuring the position of the X-ray transmission window 10b. Therefore, the sample container 4 and the optical systems 100 and 200 by the measuring means can be measured. The effect on will disappear.

As described in the above embodiments, by using the X-ray microscope according to the present invention, the visible light optical system can easily specify the region desired to be viewed with X-rays. Furthermore, the X-ray optical system 1
00 and the visible light optical system 200 to correct the difference in the refractive index,
In order to match the shift of the focus position caused when the visible light optical system 200 is switched to the X-ray optical system 100, the sample 12
Do not irradiate with extra X-rays. As a result, irradiation damage to the sample 12 can be reduced, and deterioration of the X-ray image due to defocus can be prevented.

[0091]

According to the present invention, in an X-ray microscope including a visible light optical system and an X-ray optical system, based on the position to be observed of the sample, which is focused and specified by the visible light optical system, It is possible to provide an X-ray microscope capable of focusing on the position to be observed by the X-ray optical system.

[0092]

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a part of the configuration of a first embodiment according to the present invention.

FIG. 2 (a): an explanatory view for explaining the operation of the present invention. FIG. 2 (a): an explanatory view for explaining the operation according to the present invention.

FIG. 3 is an explanatory diagram showing a part of the configuration of the second embodiment according to the present invention.

FIG. 4 is an explanatory diagram showing a part of the configuration of the third embodiment according to the present invention.

FIG. 5 is an explanatory diagram showing a configuration of a conventional X-ray microscope.

FIG. 6 is a graph showing absorption of X-rays by a substance.

FIG. 7 is a block diagram showing the configuration of a first embodiment according to the present invention.

[Explanation of symbols]

1 ... X-ray generator, 2 ... Exhaust device, 3 ... X-ray illumination system, 4 ... Sample container, 5 ... X-ray magnifying optical system,
6 ... Vacuum container, 7 ... X-ray imaging device, 8 ... Display device, 10a, 10b ... X-ray transmission window, 11 ...
Solution medium such as culture solution, 12 ... Biological sample, 21 ...
.Laser emission source, 22 ... Position detection device, 23 ...
Computation means, 23a ... Control device, 23b ... Input device, 24 ... Sample stage, 25 ... Visible light source, 26 ... Visible light illumination system, 27 ... Visible light objective lens , 28 ... Visible light imaging device, 31 ... Contact type position sensor, 41 ... X-ray transmission window container, 42 ... Stage position measuring device.

Claims (6)

[Claims] 1. An X-ray optical system comprising: an X-ray optical system for obtaining an X-ray image of a sample contained in a sample container; and a visible light optical system for obtaining a visible light image of the sample. The sample focused by the visible light optical system should be observed from the sample container displacement mechanism that displaces the sample container along at least each optical axis direction of the visible light optical system and the predetermined measurement origin. Visible light observation position measuring means for measuring the optical distance in visible light to a position, the measured optical distance in visible light, and the visible light in the sample container, which has been obtained in advance. And an X-ray observation position calculation means for calculating an optical distance of the X-ray from the origin to the position to be observed, based on the relative relationship of the refractive index with respect to the X-ray used for observation. Based on the result, control the sample container displacement mechanism,
An X-ray microscope comprising: a control means for displacing the sample container so that the focal position of the X-ray optical system coincides with the position to be observed. 2. The optical distance with visible light according to claim 1, wherein a distance from the predetermined measurement origin to a predetermined reference point on the sample container and the observation from the reference point. Consisting of the distance to the position to be observed, the visible light observation position measuring means, from the position of the sample container in the state of being focused to the reference point, in the state of being focused to the position to be observed. Sample container displacement distance measurement to measure the displacement distance in the optical axis direction of the visible light used in the visible light optical system to the position of the sample container as the optical distance from the reference point to the position to be observed. An X-ray microscope having means. 3. The visible light optical system according to claim 2, wherein a determination as to whether or not the focus is at a predetermined reference point and a position to be observed is externally received, and a signal indicating the determination is received from the sample container displacement. Further having an operation receiving means for outputting to the distance measuring means, the sample container displacement distance measuring means, based on the signal,
An X-ray microscope characterized by determining that those positions are in focus. 4. The X-ray observation position calculation means according to claim 3, wherein the relative relationship between the refractive index for the visible light and the refractive index for the X-ray in the sample container is used. An X-ray microscope characterized by converting an optical distance in visible light into an optical distance in the X-ray. 5. The sample container according to claim 4, wherein the sample container has a medium filled therein for holding the sample, and the X-ray observation position calculating means is obtained in advance. Converting the optical distance of the visible light into the optical distance of the X-ray by using the relative relationship between the refractive index of the medium with respect to the visible light and the refractive index of the medium with respect to the X-ray. Characteristic X-ray microscope. 6. The sample container according to claim 5, further comprising a pair of transmission windows that isolate the sample and the medium from a vacuum portion and transmit X-rays and visible light used for observation. The visible light observing position measuring means may set a predetermined one point on a surface of the one transmission window of the pair of transmission windows facing the vacuum portion as the predetermined reference point. Characteristic X-ray microscope.