METHOD OF THREE-DIMENSIONAL SCANNING USING FLUORESCENCE INDUCED BY ELECTROMAGNETIC RADIATION AND A DEVICE FOR EXECUTING THIS METHOD

Abstract

For volumetric analysis of the elemental composition of a measured sample (3) the method of three-dimensional scanning is executing using fluorescence induced by electromagnetic radiation, in which the primary beam (1) of electromagnetic radiation is flattened and is directed at the measured sample (3) in which it irradiates the measured area (6). From the measured area (6) there exits fluorescence radiation, which is almost completely shielded by the shielding means (7) to a secondary beam (9), which is released towards the shielded detector (4) through the permeable area (8) formed in the shielding means (7). The secondary beam (9) projects the image of the measured area (6) onto the shielded detector (4), which records the data of the measured area (6) and subsequently uses the data to obtain an elemental composition of the measured sample (3), including the distribution of concentration of elements in the sample volume.

Claims

1. A method of scanning using fluorescence induced by electromagnetic radiation in which there is generated a primary beam (1) of electromagnetic radiation from a source (2), the primary beam (1) is directed to at least one part of the measured sample (3), and by using at least one detector (4, 5) fluorescence electromagnetic radiation is detected exiting from the material of the measured sample (3), and on the basis of its spectral analysis the elemental composition of the measured sample (3) is determined, characterized in that the shape of the primary beam (1) is flattened, the flattened primary beam (1) is directed to the measured sample (3) at an angle (α) whose magnitude ranges from 0° to 90°, whereupon the penetration of the flattened primary beam (1) and the measured sample (3) forms the measured area (6), inside which there is emitted fluorescent electromagnetic radiation, the fluorescence electromagnetic radiation is shielded using a shielding means (7) positioned between the measured sample (3) and the shielded detector (4), wherein the shielding means (7) is provided with at least one permeable area (8) to create a secondary beam (9) of fluorescence electromagnetic radiation and for a clear connection of the site of radiation of the secondary beam (9) of the measured area (6) and the site of impact of the secondary beam (9) on the shielded detector (4), subsequently on the shielded detector (4) there is detected a secondary beam (9) exiting from the permeable area (8), whereupon on the basis of the shielded detector (4) of the measured data, on the value of the angle (α) and the position of the permeable region (8) towards the measured sample (3) and/or the shielded detector (4), the elemental composition is modeled in at least part of the volume of the measured sample (3).

2. A method of scanning according to claim 1, characterized in that simultaneously with the scanning of the measured sample (3) the overall spectrum of the fluorescence electromagnetic radiation is detected by the exposed detector (5), and simultaneously the transmission detector (10) detects the primary beam (1) exiting from the measured sample (3), in particular its intensity, scattering, and diffraction.

3. A method of three-dimensional scanning according to claim 1 or 2, characterized in that the measured sample (3) is moved during scanning towards the primary beam (1) so that the entire volume of the measured sample (3) may be scanned, or that the kinematic motion is reversed.

4. A device (11) for three-dimensional scanning using fluorescence induced by electromagnetic radiation according to the method stated in at least one of claims 1 to 3, comprising a source (2) of the primary beam (1) of electromagnetic radiation and at least one detector (4, 5, 10) of the electromagnetic radiation, characterized in that the source (2) of the primary beam (1) is provided with at least one modeling means for flattening the primary beam (1), the device (11) is provided with an adjustable carrier (12) for the measured object (3), towards which the primary beam (1) is angularly adjustable, further the device (11) is provided with a shielding means (7) positioned between the measured sample (3) and the shielded detector (4), wherein the shielding means (7) has at least one permeable area (8) for the passage of fluorescence electromagnetic radiation through the shielding means (7) and for the generation of a secondary beam (9).

5. A device according to claim 4, characterized in that the height (h) of the flattened primary beam (1) is in the range from 1 μm to 1 mm.

6. A device according to claim 4 or 5, characterized in that the source (2) of the primary beam (1) emits at least one type of electromagnetic radiation from the following group: monochromatic X-ray, polychromatic X-ray, gamma radiation.

7. A device according to any of claims 4 to 6, characterized in that the modeling means is formed by X-ray optics and/or a collimator.

8. A device according to any of claims 4 to 7, characterized in that the shielding means (7) is formed by a material absorbing electromagnetic radiation, and the permeable area (8) is formed by an opening, or X-ray optics, or a collimator.

9. A device according to any of claims 4 to 8, characterized in that it is provided with a transmission detector (10) for detecting changes in the intensity of the primary beam (1), and its scattering and diffraction, and further is provided with an exposed detector (5) for detecting total fluorescence radiation.

10. A device according to any of claims 4 to 9, characterized in that the detector (4, 5, 10) for detecting electromagnetic radiation is at least one of the following types of detector: X-ray spectrometer, imaging detector, pixel detector integrating a charge, pixel detector counting individual photons, energy-sensitive pixel detector.

11. A device according to any of claims 4 to 10, characterized in that the adjustable carrier (12) and/or source (2) is motorized to allow for continuous measurement of the connected measured areas zone (6) of the measured sample (3).

Description

DESCRIPTION OF THE DRAWINGS

[0027] The invention is more closely illustrated in the following drawings, wherein:

[0028] FIG. 1 presents a schematic representation of the device in cross-section,

[0029] FIG. 2 shows an axonometric schematic drawing of the scanning of the measured object,

EXAMPLES OF THE PREFERRED EMBODIMENTS OF THE INVENTION

[0030] It is understood that the hereinafter described and illustrated specific examples of the realization of the invention are presented for illustrative purposes and not as a limitation of the examples of the realization of the invention to the cases shown herein. Experts who are familiar with the state of technology shall find, or using routine experimentation will be able to determine, a greater or lesser number of equivalents to the specific realizations of the invention, which are specifically described here. These equivalents shall also be included into the scope of the patent claims.

[0031] FIG. 1 is a schematic illustration of the device 11 for three-dimensional scanning using fluorescence induced by electromagnetic radiation. The basis of the device 11 is a metal frame 13 to which the various components of the device 11 are fixed. The source 2 of the primary beam 1 is formed, in this particular example, by an X-ray tube, before which there is positioned collimator and X-ray optics. From the source 2 there radiates the primary beam 1 which is straight, flattened, its height h is 15 μm, and its width is modeled in the range of millimeters or centimeters as appropriate for the measurement. This is achieved, for example, by collimation, X-ray optics, or another method (e.g. by a synchrotron). The primary beam 1 fails on the measured sample 3.

[0032] The frame 13 and adjustable carrier 12 allow for the precise positioning of the measured sample 3 towards the source 2 and towards the primary beam 1 using motors, so the measured sample 3 can be irradiated successively in sections. In other embodiments of the invention, devices with an arbitrary principle of generating electromagnetic radiation (e.g. X-ray tube, synchrotron, radionuclide source, etc.) may serve as the source 2 of the primary beam 1. The basic condition is that the energy of the primary beam 1 is sufficient to induce fluorescence in the measured sample 3.

[0033] The measured sample 3 is mounted on the adjustable carrier 12. The carrier 12 is a table on which the measured sample 3 is laid or fixed, and secured against arbitrary movement. The carrier 12 is adjustable to correct inaccuracies when placing the measured sample 3 into the device 11.

[0034] In the path of the primary beam 1 there lies a transmission detector 10, which detects the exiting primary beam 1 of the measured sample 3. The detector 10 monitors the intensity of the primary beam 1, its dispersion and bending, thereby obtaining data on the nature of the material of the measured sample 3.

[0035] Upon penetration of the primary beam 1 through the measured sample 3, the irradiated area 6 is measured and emits fluorescence radiation, which spreads in all directions. Inside the device 11, there is therefore also stored an exposed detector 5 which detects this radiation and sends the data to be processed for each measured area 6 of the sample 3.

[0036] Part of the fluorescence radiation from the measurement area 6 spreads towards the shielded detector 4 which is hidden behind the shielding means 7. The shielding means 7 absorbs the fluorescence radiation along its entire area except for the permeable area 8 which allows for the penetration of the photons of the fluorescence radiation forming a secondary beam 9 continuing to the shielded detector 4. A pinhole camera is thus created for X-rays. A knowledge of the direction of the primary beam 1 during the irradiation of the measured sample 3 allows, from geometric dependencies, for the determination of the site in the material of the measured area 6 of the measured sample area 3 from where the fluorescence radiation was emitted. The shielding means 7 is formed by a shielding metal (e.g. lead or tungsten) and the permeable area 10 is a normal hole of small dimensions, or in another different example of an embodiment is formed by an X-ray optics, coded aperture or a collimator.

[0037] The primary beam 1 impacting below the angle α of size 10° passes through the measured sample 3 and exits from the measured sample 3. It then impacts upon the detector 10, which measures how the primary beam 1 was affected by its passage through the measured sample 3. Simultaneously with the passage of the primary beam 1 through the material of the measured sample 3 there occurs emission of fluorescence radiation. The radiation spreads in all directions, including the direction towards the shielded detector 4 stored behind the shielding means 7. Through the permeable area 8 there penetrates part of the fluorescence radiation forming a secondary beam 9 to the detection surface of the position-sensitive shielded detector 4. Given the knowledge of the orientation of the primary beam 1 towards the measured object 3, it is possible to read, from the detector 4, the data for the entire course of the primary beam 1 through the material of the measured sample 3 along its height and width. By moving the sample 3 in relation to the detector 4 and to the primary beam 1, information is then obtained from the entire volume of the measured sample 3.

[0038] Detectors 4 and 10 include either a single position- and energy-sensitive X-ray imaging detector, or several detection chips arranged in a common field. The detection chips are, for example, Timepix detectors enabling the measurement of the position and energy of the impacting radiation.

[0039] Detector 10 measures the attenuation of the primary beam 1 after its passage through the measured sample 3. It thus creates an X-ray image of the measured sample 3 during the scanning transmission. Detector 10 may be position-sensitive, and/or spectrometric same as detector 4. It then provides further information about the composition of the measured sample 3. Detector 10 can also be purely spectrometric, like detector 5. If it is a position-sensitive, it can also provide information about the photons of the primary beam 1 scattered through the sample outside this beam 1.

[0040] Detector 5 measures the total fluorescence spectrum emitted from the entire irradiated volume of the sample 3. This detector 5 is not position-sensitive, but has a good energy resolution. An analysis of the spectrum measured by the detector 5 provides an overall concentration of elements in the irradiated volume (i.e. without information on distribution in space). The detector 5 may be, for example, an SDD (silicon-drift detector) type.

[0041] Information from detectors 5 and 10 may be used separately (transmission image and total elemental composition). Or it may be used in the analysis of the spectra measured in the pixels of detector 4. An overall knowledge of the elemental composition obtained by detector 5 will reduce the number of free parameters in the analysis of data from detector 4. Data from detector 10 can be used to obtain a correction for self-shielding in the sample 3 when determining the concentrations of elements from the spectra in detectors 4 and 5.

[0042] Detectors 4, 5, 10 are adjustable on the frame 2, either positionable by handles or by motors.

[0043] During the scanning, the measured sample 3 can be moved on the carrier 12, or the detectors 4, 5, 10 and the source 2 may be moved in individual steps. The decisive factor is the size and shape of the measured sample 3.

INDUSTRIAL APPLICABILITY

[0044] The method and device for three-dimensional scanning according to the invention shall find application in the field of restoration of works of art, in the field of printed circuit boards, integrated circuits, non-destructive testing, or in the field of analysis of layered composite materials.

OVERVIEW OF THE POSITIONS USED IN THE DRAWINGS

[0045] 1 primary beam of electromagnetic radiation [0046] 2 source of the primary beam of electromagnetic radiation [0047] 3 measured sample [0048] 4 shielded detector [0049] 5 exposed detector [0050] 6 measured area [0051] 7 shielding means [0052] 8 permeable area [0053] 9 secondary beam of fluorescence electromagnetic radiation [0054] 10 transmission detector [0055] 11 device for three-dimensional scanning [0056] 12 adjustable holder for the measured sample [0057] 13 frame for attaching the parts of the device [0058] α angle between the primary beam and the measured sample [0059] h height of the flattened primary beam