X-ray systems and methods

Abstract

An x-ray system is disclosed comprising: an electron impact x-ray source configured to generate an x-ray beam; a radiation-shielded enclosure having an x-ray exit port; an x-ray optic disposed within the radiation-shielded enclosure and configured to direct the x-ray beam toward the exit port; a shutter disposed at the exit port, the shutter movable between an open position that allows x-ray output through the exit port and a closed position that prevents x-ray output through the exit port; and a detector directed toward the exit port and positioned to detect x-ray radiation from the x-ray source, the detector configured to detect x-ray radiation within a first energy range. Corresponding methods of operating the x-ray system are also disclosed.

Description

Technical Field

[0005] ,

[0004] , , , ,

[0001] The present invention generally relates to an X-ray system.

Background Art

[0002] An X-ray system typically includes an X-ray source and an X-ray optical system arranged to collect and direct the X-ray radiation generated by the X-ray source. Thus, the amount of useful X-ray radiation that can be made available from the X-ray system is partially determined by the amount of radiation that can be collected by the optical system. The prior art is limited in this regard by the overall safety requirements and geometric constraints that limit how much of the generated radiation is collected and can be usefully made available as the output from the X-ray system.

Summary of the Invention

[0003] A typical prior art X-ray system includes an X-ray source having a shutter and an X-ray optical element for collecting the generated X-ray radiation and providing a useful output. As will be appreciated, more useful X-ray radiation can be made available if the X-ray optical system is placed closer to the X-ray source. However, in the prior art, the minimum distance between the source and the optical system is determined by the internal geometry of the source and the dimensions of the shutter. [[ID=I20]] <000001 '6> The shutter is required for safety reasons, as it must always be able to protect the surroundings, especially humans, from unintentional exposure to X-rays. If the X-ray optical system is not properly adjusted, when the source is turned on, the radiation could potentially reach almost anywhere. Thus, in the prior art, the X-ray optical system is placed downstream of the shutter, which limits how short the distance between the source and the optical system can be, and thus also limits how much useful X-ray radiation can be made available.

[0005] The present invention provides a safe method for placing the optical system closer to the radiation source, preferably by providing a radiation shielding housing having only one intended X-ray outlet. The housing may be an extension of the X-ray source enclosure, or it may be connected to the enclosure, either rigidly or flexibly. To prevent any leakage of X-ray radiation, it may even be conceivable that the source and housing be separated from each other, if a radiation trap exists where the source and housing meet. The present invention is particularly useful in electron shock X-ray systems, where X-ray radiation is generated by the interaction between an electron beam and a target. The target may be a solid target, such as a reflective or transmission target, or a liquid target, such as a liquid jet target.

[0006] The general idea underlying the present invention is that one or more X-ray optical elements may be positioned closer to the X-ray source when arranged within such a radiation shielding enclosure, and therefore upstream of the shutter, where the shutter, which prevents unintended output of X-ray radiation, is located at the exit port of the radiation shielding enclosure. The X-ray optical system is configured to direct the X-ray radiation generated by the X-ray source toward the exit port. Thus, the radiation shielding enclosure serves the purpose of preventing leakage of X-ray radiation and allowing only output through the exit port, and the shutter is used to control whether output through the exit port is allowed or not.

[0007] Conventionally, safety shutters have been integrated with the X-ray source, i.e., incorporated into the X-ray source, and the X-ray optics and / or monochromator have been located downstream of the safety shutter. Therefore, moving the safety shutter to a position downstream of the optics / monochromator instead might seem counterintuitive to those skilled in the art. However, according to the present invention, this is made possible by a radiation shielding housing in which the X-ray optical elements are located.

[0008] Conveniently, one or more detectors may be provided inside the radiation shielding housing to detect X-ray emission directed toward the exit port. For example, the detector may be attached to the shutter on the side facing the interior of the radiation shielding housing. Such detectors may preferably be embodied as one or more diodes. Alternative detectors may include pixelated detectors that provide more information during alignment, or scintillator-based detectors that can provide better sensitivity. Embodiments include a detector configured to detect X-ray emission within a first energy range. The energy range may have an upper limit, a lower limit, or both upper and lower limits. In exemplary embodiments, a filter is arranged to prevent X-ray emission with energies outside the first energy range from reaching the detector. Other embodiments may include separate detection of X-ray emission from at least first and second energy ranges. Specifically, separate detection of X-ray photons having energies within a desired energy range and X-ray photons having energies above the desired energy range may be advantageous. A first signal generated by photons within the desired energy range may be used during the alignment procedure. The alignment between the X-ray source and the X-ray optical element, and / or between the X-ray optical element and the exit port, may be adjusted to amplify this signal. A second signal generated by photons having energy above the desired energy range may be used to mitigate malfunctions, as described below.

[0009] Inclusion of a detector configured to detect X-ray radiation within a certain energy range directed toward the exit port is advantageous in that it can be used as a alignment tool, allowing for easier or automated adjustment of the position and / or orientation of the X-ray optical elements by the operator. Furthermore, such a detector can also be used, together with a shutter positioned at the exit port, to prevent X-ray radiation with energies outside the desired energy range from being emitted through the exit port. These and other advantages are further described below in various exemplary embodiments.

[0010] Typically, X-ray systems are designed to deliver X-ray radiation within a predetermined photon energy range, and monochromatic X-ray optics are commonly used for this purpose. However, in the event of malfunctions such as misalignment of components in the X-ray system, X-ray radiation with photon energies outside the predetermined range may pass through the optics. In some embodiments, such situations are addressed by configuring detectors to separately detect photons with energies outside the predetermined energy range, for example, those with energies above the predetermined energy range. If it is detected that the amount of photons with energies outside the predetermined energy range exceeds a predetermined threshold, the system may be configured to ensure that a shutter is in the closed position to prevent the output of any X-ray radiation of such energies through the exit port. The movement of the shutter between the closed and open positions is preferably carried out using an electromechanical actuator, motor, or similar.

[0011] The X-ray system may also be provided with an outer radiation shield or cabinet configured to block radiation. The cabinet may enclose at least some of the following: the X-ray source, the X-ray optics, the sample position, and the detection device. For example, such an outer cabinet may be configured to block radiation at photon energies corresponding to those energies that the X-ray optics are designed to provide as output. Thus, in some implementations, the detector may be configured to detect radiation that is insensitive to radiation corresponding to the intended output but which may risk passing through the outer cabinet. In this way, X-ray radiation with energies higher than a given energy range, which would otherwise be inadvertently emitted and, in some cases, could penetrate the outer radiation shield, can be contained within the inner radiation shield by ensuring that it is detected and that a shutter is closed when such X-ray radiation is detected.

[0012] Providing a detector for detecting X-ray emission directed toward the exit port can also be used for aligning components of the X-ray system. By detecting X-ray emission directed toward the exit port, for example, emission within a predetermined range, and by supplying the detector signal from the detector to the control device, the alignment between the X-ray source and the X-ray optics, and / or between the X-ray optics and the exit port, can be adjusted by the control device so that the detector signal increases. For this purpose, the control device is preferably coupled to a manipulator that can be used to move the X-ray spot of the X-ray source and / or the position or orientation of the X-ray optics. Conveniently, such alignment can be performed while the shutter is in its closed position, thus preventing any X-ray emission from being output through the exit port. Therefore, the manipulator arranged to adjust the position and / or orientation of the X-ray optical elements is preferably controllable from outside the radiation shielding housing. This is advantageous in that insufficient alignment can cause X-ray emission with energy outside a predetermined range to reach the exit port.

[0013] Movement of the X-ray spot relative to the X-ray optical system can be achieved, for example, by moving the entire X-ray source, by deflecting the electron beam that strikes the target to generate X-ray emission onto the target, or by moving the X-ray target. Different modes of translation can be used in different directions; for example, movement of the X-ray spot in a first direction can be achieved by deflecting the electron beam, while movement along another direction, such as perpendicular to the first direction, can be achieved by moving the target.

[0014] The movement of the X-ray optical system can be achieved, for example, using a motor such as a stepping motor, or an actuator such as an electromagnetic actuator or a piezoelectric actuator.

[0015] Several modifications and variations are possible within the scope of the present invention. In particular, X-ray sources having multi-material targets, one or more targets, or one or more electron beams are conceivable within the scope of the present invention. Also contemplated are X-ray optical systems designed to direct X-ray emission of one or more clearly defined wavelengths. Furthermore, the types of X-ray systems described herein may be advantageously constructed for specific applications exemplified by, but not limited to, medical diagnostics, non-destructive testing, lithography, crystal analysis, microscopy, materials science, microscopic surface physics, protein structure determination by X-ray diffraction, X-ray photospectroscopy (XPS), critical dimension small-angle X-ray scattering (CD-SAXS), and X-ray fluorescence (XRF).

[0016] In the embodiments for carrying out the following invention, references are made to the attached drawings. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 shows a schematic example of an X-ray system. [Figure 2] Figure 2 schematically shows another example of an X-ray system. [Figure 3] Figure 3 schematically shows another example of an X-ray system. [Figure 4] Figure 4 schematically shows an exemplary detector arrangement. [Figure 5] Figure 5 shows a schematic flowchart of the method according to the present invention. [Modes for carrying out the invention]

[0018] Figure 1 schematically shows an example of an X-ray system. The X-ray system includes an enclosure 3 from which X-ray radiation is emitted through an X-ray transmission window 4. The X-ray radiation is generated when electrons are emitted from an electron source 1 and collide with a target 2 in the interaction region, thus creating an X-ray spot. A radiation shielding housing 5 is positioned adjacent to the enclosure 3 and receives the X-ray radiation emitted through the window 4. An X-ray optical system 6 is provided inside the radiation shielding housing 5. In this example, housing 5 and enclosure 3 are independently movable relative to each other. Therefore, alignment can be performed by moving either housing 5 or enclosure 3, or both. To prevent radiation leakage, a radiation trap 9 may be placed at the interface between housing 5 and enclosure 3. Housing 5 is provided with an exit port through which X-ray radiation can be output. To prevent unintended X-ray emission, the exit port is provided with a shutter 7 that can move between an open position that allows X-ray emission through the exit port and a closed position that prevents X-ray emission through the exit port. When the shutter 7 is closed, no X-ray emission is emitted into the surrounding environment. When the shutter 7 is open, X-ray emission may be emitted through the exit port in the housing, which would otherwise be covered by the shutter. To detect any X-ray emission directed toward the exit port, one or more detectors (shown as reference numeral 8 in Figure 1) may be provided, for example, on the shutter 7. Thus, when the shutter 7 is closed, the detector(s) 8 provide a signal indicating the amount of X-ray emission that has reached the shutter. During the alignment procedure, the relative position of the X-ray optical system and the X-ray spot may be adjusted to increase this signal.

[0019] Alternatively, the alignment procedure could be performed based on feedback from a detector located at the sample location (i.e., the location where the sample under investigation should be placed) or in the beam path upstream or downstream of the sample location. In this case, the shutter 7 would remain open during the alignment procedure so that X-ray radiation reaches the detector.

[0020] The X-ray optical element 6 may be a mirror such as a multilayer mirror, a zone plate, a monocapillary optical element, or a polycapillary optical element. In some preferred embodiments, the X-ray optical element is a Montell mirror. In other embodiments, the X-ray optical element may be implemented as a crystalline optical system, such as a double-curved crystal optical system (DCC optical system).

[0021] The inside of the radiation shielding enclosure 5 may be under reduced pressure, or it may be filled with an inert gas such as helium or nitrogen. One reason for keeping the inside of the enclosure 5 under reduced pressure or filling it with an inert gas may be to reduce the accumulation of contaminants on the optical system 6, and / or to reduce the scattering and absorption of X-ray radiation.

[0022] Another exemplary implementation is schematically shown in Figure 2. In this example, the housing 5 is rigidly attached to the enclosure 3. In this implementation, alignment can be performed by adjusting either the position or orientation of the X-ray optical system 6, or the location of the X-ray spot on the target 2, by moving the electron beam produced by the electron source 1 using the manipulator 10. Since the housing 5 is rigidly connected to the enclosure 3 to shield from radiation, as long as the shutter 7 is closed, no X-ray radiation is present outside the housing, regardless of how the alignment procedure is performed. In this implementation, the electron source 1 may include suitable electro-optical components such as deflection plates or alignment coils for adjusting the location of the X-ray spot on the target 2. The manipulator 10 may provide manual or motorized movement of the X-ray optical system. Preferably, the manipulator 10, the X-ray source 1, and the detector 8 are connected to a control device 11 for automatic alignment (shown as a dashed line in the figure) so that the alignment adjustment can be conveniently performed to increase the detector signal. This implementation configuration can provide a shorter distance between the optical system 6 and the X-ray spot on the target 2. Since the X-ray source 1 is contained within the enclosure 3, there is no need to provide a reduced pressure inside the housing 5. The window 4 acts as the interface between the reduced pressure region inside the enclosure 3 and the housing 5. Since the housing 5 only needs to provide radiation shielding, the structure of the manipulator 10 can be simplified to some extent. The housing 5 can be flushed with an inert gas such as helium to reduce air scattering and absorption and also to prevent contamination of the X-ray optical system.

[0023] Another exemplary implementation is schematically shown in FIG. 3. In this implementation, the radiation shielding housing 5 is extended to also include an enclosure for the X-ray source 1. In this case, the distance between the target 2 (and thus the X-ray spot) and the X-ray optical system 6 can be further reduced since no X-ray transmission window is required therebetween. The decompression region is provided within the radiation shielding housing 5 in this case. Thus, the X-ray transmission window 4 is preferably provided at the exit port and will thus be covered by the shutter 7 when the shutter 7 is in its closed position. An implementation of the type shown in FIG. 3 can be useful for X-ray systems designed to provide soft X-ray radiation (energy below about 4 keV). The X-ray source 1, the manipulator 10 for the X-ray optical system, and the detector(s) 8 can be connected to the control device 11 in a similar manner as in the implementation of FIG. 2.

[0024] An exemplary detector arrangement is schematically shown in FIG. 4. A plan view of the shutter 7 is shown as seen along the X-ray beam path inside the housing 5. The exit port through which the X-ray radiation is emitted from the housing 5 is schematically shown as a dotted circle in FIG. 4. Two diodes 101, 1,02 are provided on the shutter 7 at locations that will be positioned in front of the exit port when the shutter is in the closed position. The first diode 101 is arranged closest to the X-ray optical system and is used to detect X-ray radiation within a predetermined desired energy range. The second diode 102 is arranged behind the first diode as seen in the direction of the emitted X-ray radiation. In FIG. 4, a part of the second diode 102 is drawn in dashed lines to illustrate that it is located behind the first diode, 101. Thus, the first diode can function as a high-pass filter for the second diode. The second diode can then be used to detect whether X-ray radiation having an energy outside the predetermined energy range has been emitted from the X-ray optical system. If further energy filtering is required, an optional filter (not shown in FIG. 4) can be arranged between these two diodes.

[0025] Generally, an embodiment may include one or more electromechanical actuators, motors, or the like for effecting movement of the shutter between its closed and open positions. Such an actuator, motor, or the like may be connected to the control device described above or may have one or more separate dedicated control devices. In implementations where the position of the shutter is to be controlled based on an input from a detector, it is preferred to connect the detector and the actuator / motor to a common control device. The X-ray system may be implemented using a single control device that processes all control inputs and outputs.

[0026] Referring to FIG. 5, an exemplary method of operating an X-ray system according to the present invention comprises generating an X-ray beam 501 using an electron-impact X-ray source and directing the X-ray beam into a radiation shield housing having an X-ray exit port 502. The X-ray beam is directed towards the exit port 503 using X-ray optical elements disposed within the radiation shield housing. A shutter disposed at the exit port is used 504 to enable or prevent X-ray output through the exit port, where the shutter is moved between an open position that enables X-ray output through the exit port and a closed position that prevents X-ray output through the exit port. The method may also include detecting 505 X-ray radiation directed towards the exit port. Optionally, the method may include a further step 506 of aligning the relative orientation of the X-ray source spot and the X-ray optics to increase the amount of X-ray radiation emitted through the exit port. This may preferably be done by using a control device connected to both one or more detectors and an alignment manipulator in the X-ray system to adjust the relative orientation while the shutter is closed. The adjustment may be made such that the detected amount of X-ray radiation directed towards the exit port increases. The control device may be configured to stop further adjustment when the achieved increase is below a threshold value. Further, the method may include a step of ensuring that the shutter is closed by the control device when the detector detects X-ray radiation having an energy outside a predetermined range.

[0027] In a further embodiment, the method comprises adjusting the relative orientation between the X-ray spot and the X-ray optical system, and / or between the X-ray optical system and the exit port, such that the amount of detected X-ray radiation having an energy outside a predetermined range is below a predetermined threshold. Preferably, this adjustment is performed by a control device while the shutter is closed, thereby preventing X-ray radiation having an energy outside a predetermined range from being emitted through the exit port.

[0028] [In conclusion] An X-ray system is disclosed comprising: an electron impact X-ray source configured to generate an X-ray beam; a radiation shielding housing having an X-ray exit port; an X-ray optical element disposed within the radiation shielding housing and configured to direct the X-ray beam toward the exit port; a shutter positioned at the exit port, the shutter being movable between an open position that allows X-ray output through the exit port and a closed position that prevents X-ray output through the exit port. In some embodiments, the X-ray emission directed toward the exit port is detected to facilitate the alignment of components in the system and / or to prevent unintended emission for safety reasons. A corresponding method for operating the X-ray system is also disclosed. The following is a direct reproduction of the claims as originally filed. [1] An X-ray system, An electron blast X-ray source configured to generate an X-ray beam, A radiation shielding enclosure having an X-ray exit port, An X-ray optical element is disposed within the radiation shielding housing and configured to direct the X-ray beam toward the X-ray exit port, A shutter is positioned at the X-ray exit port, wherein the shutter is movable between an open position that allows X-ray output through the X-ray exit port and a closed position that prevents X-ray output through the X-ray exit port. The system comprises a detector oriented toward the aforementioned X-ray exit port and positioned to detect X-ray emission from the electron blast X-ray source, An X-ray system in which the detector is configured to detect X-ray radiation within a first energy range. [2] The system according to [1], wherein the detector comprises a filter that prevents the detection of X-ray radiation having an energy outside the first energy range. [3] The system according to [1] or [2], wherein the detector comprises a diode. [4] The system according to any one of [1] to [3], wherein the detector comprises a first detector element for detecting X-ray radiation in a first energy range and a second detector element for detecting X-ray radiation in a second energy range. [5] The system according to any one of [1] to [4], wherein the X-ray optical element is configured to transmit only X-ray photons within a predetermined energy range. [6] The system according to [5], wherein the first energy range is selected to be outside the predetermined energy range, and in particular above the predetermined energy range. [7] The system according to [5] or [6], wherein the system is configured to ensure that the shutter is in the closed position when a detected photon having an energy outside the predetermined energy range exceeds a predetermined threshold. [8] The system further comprising a control device connected to receive a detector signal from the detector indicating X-ray emission within a desired energy range, wherein the control device is arranged to adjust the alignment between the electron blast X-ray source and the X-ray optical element and / or between the X-ray optical element and the X-ray exit port so that the detector signal increases. [9] The system according to any one of [1] to [8], further comprising a manipulator that is controllable from outside the radiation shielding housing and is arranged to adjust the position and / or orientation of the X-ray optical element.

[10] A method for operating an X-ray system, Using an electron blast X-ray source to generate an X-ray beam, The X-ray beam is directed into a radiation shielding enclosure having an X-ray exit port, The X-ray optical element arranged within the radiation shielding housing is used to direct the X-ray beam toward the X-ray exit port, The shutter is used to allow or prevent X-ray output through the X-ray exit port by moving the shutter between an open position that allows X-ray output through the X-ray exit port and a closed position that prevents X-ray output through the X-ray exit port, To detect X-ray emission within a first energy range, directed toward the aforementioned X-ray exit port, A method for providing this.

[11] The method according to

[10] , wherein the X-ray optical element is configured to transmit X-ray radiation within a predetermined energy range.

[12] The method according to

[11] , wherein the first energy range is selected to be outside the predetermined energy range, and in particular above the predetermined energy range.

[13] The method of

[12] , further comprising ensuring that the shutter is in the closed position if a detected photon having an energy outside the predetermined energy range exceeds a predetermined threshold.

[14] The method of any one of

[10] to

[13] , further comprising adjusting the alignment between the electron shock X-ray source and the X-ray optical element and / or between the X-ray optical element and the X-ray exit port so as to increase the detected X-ray emission in a desired energy range directed toward the X-ray exit port.

[15] The method according to

[13] , further comprising adjusting the alignment between the electron shock X-ray source and the X-ray optical element, and / or the alignment between the X-ray optical element and the X-ray exit port, in order to reduce the detected photons having an energy outside the predetermined energy range to below the threshold.

Claims

1. It is an X-ray system, An electron blast X-ray source configured to generate an X-ray beam, A radiation shielding enclosure having an X-ray exit port, An X-ray optical element is disposed within the radiation shielding housing and configured to direct the X-ray beam toward the X-ray exit port, A shutter is positioned at the X-ray exit port, wherein the shutter is movable between an open position that allows X-ray output through the X-ray exit port and a closed position that prevents X-ray output through the X-ray exit port. The radiation shielding housing comprises a detector positioned in the shutter and configured to detect X-ray radiation directed toward the X-ray exit port, from the electron blast X-ray source, An X-ray system in which the detector is configured to detect X-ray radiation within a first energy range.

2. The system according to claim 1, wherein the detector includes a filter that prevents the detection of X-ray radiation having an energy outside the first energy range.

3. The system according to claim 1 or 2, wherein the detector comprises a diode detector, a pixelated detector, or a scintillator-based detector.

4. The system according to any one of claims 1 to 3, wherein the X-ray optical element is configured to transmit only X-ray photons within a predetermined energy range.

5. The system according to claim 4, wherein the first energy range is selected to be outside the predetermined energy range.

6. The system according to claim 5, wherein the first energy range is selected to fall above the predetermined energy range.

7. The X-ray system is configured to ensure that the shutter is in the closed position when the amount of detected photons having energy within the first energy range detected by the detector exceeds a predetermined threshold, according to claim 5 or 6.

8. The system according to claim 4, wherein the first energy range is selected to be within the predetermined energy range.

9. The system according to claim 8, further comprising a control device connected to receive a detection signal from the detector indicating X-ray emission within the first energy range, wherein the control device is configured to adjust the alignment between the electron shock X-ray source and the X-ray optical element, and / or the alignment between the X-ray optical element and the X-ray exit port, such that the detection signal increases.

10. The system according to any one of claims 1 to 7, wherein the detector comprises a first detector element for detecting X-ray radiation in a first energy range and a second detector element for detecting X-ray radiation in a second energy range, and the X-ray system further comprises a control device connected to receive a detector signal indicating X-ray radiation in a second energy range from the second detector element, the control device being configured to adjust the alignment between the electron shock X-ray source and the X-ray optical element, and / or the alignment between the X-ray optical element and the X-ray exit port, such that the detector signal increases.

11. The system according to any one of claims 1 to 10, further comprising a manipulator that is controllable from outside the radiation shielding housing and configured to adjust the position and / or orientation of the X-ray optical element.

12. A method for operating an X-ray system, Using an electron blast X-ray source to generate an X-ray beam, The X-ray beam is directed into a radiation shielding enclosure having an X-ray exit port, The X-ray optical element arranged within the radiation shielding housing is used to direct the X-ray beam toward the X-ray exit port, The shutter is used to allow or prevent X-ray output through the X-ray exit port by moving the shutter between an open position that allows X-ray output through the X-ray exit port and a closed position that prevents X-ray output through the X-ray exit port, and the shutter is positioned at the X-ray exit port. Using a detector placed within the radiation shielding enclosure, X-ray radiation within a first energy range, directed toward the X-ray exit port, A method for providing this.

13. The method according to claim 12, wherein the X-ray optical element is configured to transmit X-ray radiation within a predetermined energy range.

14. The method according to claim 13, wherein the first energy range is selected to be outside the predetermined energy range.

15. The method according to claim 14, further comprising ensuring that the shutter is in the closed position when the amount of detected photons having energy within the first energy range detected by the detector exceeds a predetermined threshold.

16. The method according to claim 13, wherein the first energy range is selected to be within the predetermined energy range.

17. The method according to claim 16, further comprising adjusting the alignment between the electron shock X-ray source and the X-ray optical element, and / or the alignment between the X-ray optical element and the X-ray exit port, such that the X-ray emission within the first energy range detected by the detector, which is directed toward the X-ray exit port, is increased.

18. The method according to any one of claims 12 to 15, wherein the detector comprises a first detector element for detecting X-ray radiation in a first energy range and a second detector element for detecting X-ray radiation in a second energy range, and the method further comprises adjusting the alignment between the electron shock X-ray source and the X-ray optical element, and / or the alignment between the X-ray optical element and the X-ray exit port, such that the X-ray radiation in the second energy range detected by the second detector element is increased and directed toward the X-ray exit port.

19. The method of claim 18, as dependent on claim 15, further comprising adjusting the alignment between the electron shock X-ray source and the X-ray optical element, and / or the alignment between the X-ray optical element and the X-ray exit port, in order to reduce the amount of detected photons having an energy within the first energy range detected by the detector to below a predetermined threshold.

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