X-ray examination device

Description

Technical field

[0001] The present invention relates to a device for examining a sample by means of X-ray radiation and further relates to a method for producing a device for examining a sample by means of X-ray radiation. Background of the invention

[0002] Apparatus for examining various samples using X-rays is known from the state of the art.

[0003] US Pat. No. 4,263,510 discloses a combined X-ray diffraction and fluorescence spectroscopy apparatus with an environmentally controllable chamber. Using an environmentally controllable chamber can increase sensitivity, allowing elements with low atomic numbers to be measured in an improved manner. The apparatus has a relatively high number of sealing elements and is highly complex. Furthermore, the range of measurable scattering angles is limited.

[0004] Document US 2017 / 0356862 A1 discloses a measuring chamber for a compact goniometer in an X-ray spectrometer. A first goniometer arm holds an analyzer crystal, and a second goniometer arm holds an X-ray detector. The measuring chamber includes an entrance opening for the entry of X-ray fluorescence radiation into the measuring chamber. The measuring chamber is characterized by having a bearing block for receiving and holding both goniometer arms in a concentric and rotatable manner. However, the device is very bulky, and both the detector and the sample rotate during a measurement. For certain sample types, however, the rotation of the sample during the measurement is disadvantageous and can distort measurement results.

[0005] WO 01 / 46677 A2 discloses a device for examining a sample by means of X-ray radiation, comprising a flexible bellows connection.

[0006] It is therefore an object of the present invention to provide a device for examining a sample by means of X-ray radiation, wherein the measurable scattering angle range is relatively large or sufficiently large, wherein the device is compact and in particular composed of few parts and furthermore enables different sample types to be measured in a reliable manner.

[0007] It is also an object of the present invention to provide an X-ray diffractometer with an easily exchangeable vacuum chamber. Summary of the invention

[0008] This object is achieved by the subject matter of the independent claim. The dependent claims specify particular embodiments of the present invention.

[0009] According to one embodiment of the present invention, a device for examining a sample by means of X-ray radiation is provided, comprising a radiation generation system for generating primary radiation; a first goniometer arm on which the radiation generation system is mounted and which is pivotable about a goniometer axis; a detection system configured to detect secondary radiation emanating from the sample; a second goniometer arm on which the detection system is mounted and which is pivotable about the goniometer axis;an evacuable sample chamber, within which the sample can be arranged in a sample region encompassing part of the goniometer axis. The sample chamber is delimited by a sample chamber wall having a vacuum-tight transmission region that is permeable to the primary radiation, allowing the primary radiation to penetrate the sample chamber and impinge on the sample region at different angles of incidence. The sample chamber has a first opening in a detection beam path, through which the sample chamber and the detection system can be connected in a vacuum-tight manner, so that the detection beam path can be evacuated.

[0010] The radiation generation system can comprise an X-ray tube, with electrons emerging from a filament (cathode) and striking an anode designed as a metal block. Bremsstrahlung can be generated due to the deceleration of the electrons. Furthermore, electrons can be knocked out of the shells of metal atoms by electron collisions. Electrons from higher atomic shells fall back into the lower-energy shells, emitting characteristic X-ray radiation. The anode can comprise, for example, molybdenum, copper, tungsten, cobalt, chromium, or a combination thereof. In particular, the primary radiation can comprise characteristic copper lines, particularly copper Ka radiation, cobalt Ka radiation, or chromium Ka radiation. The wavelength of the primary radiation can, for example, be between 10 nm and 5 pm. The energy of the primary radiation can, for example, be between 1 keV and 50 keV.The radiation generation system may include beam-shaping optics and / or one or more filters. The radiation generation system may be configured to generate a beam of primary radiation with a desired cross-sectional size, a desired cross-sectional profile, and / or a desired wavelength or wavelength range.

[0011] The radiation generation system can, in particular, be operated under ambient pressure, i.e., normal atmospheric pressure, thus operating in a pressure range, e.g., between 950 mbar and 1050 mbar. The radiation generation system can be mounted on the first goniometer such that the generated primary radiation is directed onto the sample region within the goniometer axis for each set pivot angle. Thus, different angles of incidence of the primary radiation onto a sample can be set, which can be arranged in the sample region (a region encompassing the goniometer axis).

[0012] The secondary radiation can have substantially the same wavelength or the same wavelength range as the primary radiation, and can thus be formed in particular by elastic interaction of the primary radiation with the sample, and can thus comprise scattered radiation, in particular elastic scattered radiation. In other embodiments, the secondary radiation can have different wavelengths or different wavelength ranges or a different wavelength range than that which characterizes the primary radiation. By irradiating the sample with the primary radiation, for example, X-ray fluorescence can be excited, so that the secondary radiation at least partially comprises fluorescence radiation that can emanate from a sample or is irradiated.

[0013] In the simplest case, the detection system can be implemented, for example, as a point detector or as two-dimensional or three-dimensional arrays of detection elements that can be individually read. By pivoting the second goniometer, the detection system can be pivoted such that secondary radiation originating from the sample area and emerging at different angles of reflection can be detected by the detection system. Thus, the device allows the angle of incidence of the primary radiation impinging on the sample to be adjusted within a specific range and can also enable the detection of secondary radiation emerging from the sample area at a specific range of angles of reflection.

[0014] The sample chamber is evacuatable in the sense that a pressure can be achieved within the sample chamber which is lower than ambient pressure or atmospheric pressure, in particular a pressure of, for example, less than 100 mbar or less than 50 mbar or less than 30 mbar or even less than 10 mbar. The reduced pressure within the sample chamber corresponds to a reduced air density relative to atmospheric air density. Due to the reduced air density, absorption of X-rays or secondary radiation emanating from the sample and entering the detection system for detection is reduced. In particular, a vacuum can prevail along the entire detection beam path, i.e. between the sample arranged in the sample region and a sensor or a detection element of the detection system, which vacuum essentially corresponds to or is equal to the vacuum within the sample chamber.Due to the reduced absorption of secondary radiation achieved in this way, the measuring sensitivity of the device can be improved compared to the state of the art.

[0015] The device can further comprise an adjustment system for spatially arranging the sample (which is, for example, received in a sample holder or held by means of a sample holder) in a predetermined or desired manner relative to the goniometer axis or the sample region. For example, a surface of the sample or a central region of the sample can be adjusted so that the surface region or the central region of the sample lies in a part of the goniometer axis. The primary radiation can also be directed onto this part of the goniometer axis (in particular the sample region) for all different angles of incidence. Likewise, the secondary radiation emanating from or originating from this part of the goniometer axis can be detectable by the detection system for all different pivot angles of the detection system.

[0016] The sample chamber can have a sample interior in which the sample is arranged during the measurement. The sample can have a fixed position during the measurement and can be attached or held to a base component (e.g. via a sample holder and / or sample holder). The sample chamber can be movable relative to the base component or the sample holder, in particular rotatable, in particular rotatable about the goniometer axis. In order to be able to set a desired angle of reflection for detection, the sample chamber can be pivoted together with the detection system. The sample chamber can thus be pivoted or rotated synchronously with the detection system, if the latter is connected to the sample chamber. When pivoting the detection system by pivoting the second goniometer arm (e.g.By means of a motor or actuator, a torque can be applied to the sample chamber via a connecting system in order to pivot the sample chamber essentially synchronously with the detection system.

[0017] Both the radiation generation system and the detection system can be configured to set a desired angle of incidence or angle of reflection with high precision using high-precision bearings. For example, the angle of incidence and / or angle of reflection can be adjusted with an accuracy of, for example, 1 / 100 of a degree or better than 1 / 100 of a degree, or 1 / 1000 of a degree or better than 1 / 1000 of a degree, or 1 / 1000 of a degree to 1 / 10,000 of a degree.

[0018] The sample chamber can be pivoted about the goniometer axis during a measurement, which can in particular be arranged concentrically with a second opening described in detail below. Although it is particularly advantageous to perform a measurement with the sample inside the sample chamber and with the sample chamber evacuated, in certain cases a measurement can also be performed without a sample chamber. In this case, the detection beam path does not necessarily have to be evacuated.

[0019] The sample chamber or the sample chamber wall can be made essentially of metal, e.g. steel. The transmission area can allow primary radiation generated outside the sample chamber to enter an interior of the sample chamber, in particular allowing the primary radiation to enter or impinge on the sample area within the sample chamber at different angles of incidence. The transmission area can be made of one or more materials that are transparent to the primary radiation or cause a slight attenuation. Transparent to the primary radiation can mean that, for example, between 50% and 80% of an intensity upstream of the transmission area can pass to the downstream of the transmission area. The transmission area can be essentially airtight and, for example, sealed against other materials of the sample chamber wall by means of sealing elements, e.g.The sample chamber can be sealed with elastic sealing elements such as rubber seals. The sample chamber can optionally also have a viewing window, for example on one end, which allows a user to inspect the sample area or the sample within the sample chamber. The sample chamber can also include a door, for example, to allow the sample to be introduced into the sample chamber. This makes it possible to provide a compact device, whereby a sample can be measured using X-rays with high sensitivity and over a wide scattering angle range.

[0020] According to one embodiment of the present invention, the device further comprises a connection system which is designed for the detachable, vacuum-tight, in particular elastic or rigid, connection of the sample chamber to the detection system at the first opening, wherein the connection system comprises at least one first sealing element, wherein the first opening is in particular circular or rectangular.

[0021] The detachable connection via the connection system allows the sample chamber to be separated from the detection system. This can also allow the sample chamber to be removed, so that, for example, the sample area can also be exposed to ambient pressure. The connection system can comprise one or more parts. The connection system can, for example, comprise a vacuum flange and / or other elements. Even if the sample chamber is connected to the detection system via the connection system, a certain flexibility or mobility of the sample chamber relative to the detection system can be enabled, while a vacuum-tight connection can be ensured.Due to the (slight) relative mobility of the detection system relative to the sample chamber, overdetermination of the mechanical system can be avoided, especially if the detection system is characterized by a high-precision bearing or highly accurate mobility or pivotability via the second goniometer arm. Despite an elastic connection between the sample chamber and the detection system, sufficient torque can be exerted on the sample chamber when the detection system is pivoted, so that the sample chamber is rotated or pivoted synchronously with the detection system when the detection system is pivoted.

[0022] The first sealing element may comprise one or more seals to enable a vacuum-tight connection.

[0023] At the first opening, for example, a vacuum flange can be rigidly connected, or an (elastically connected) sleeve with a flange can be provided. The detection system can be connected to the flange, for example, in an elastic or vacuum-tight manner. The connection system can, for example, have essentially cylindrical symmetry. The connection system can be arranged such that the secondary radiation can propagate along a longitudinal axis of the connection system, specifically outside the sample chamber to a sensor element of the detection system.

[0024] According to one embodiment of the present invention, the connection system has an external thread and a union nut, wherein the at least one first sealing element has an annular seal made of elastic material, which can be compressed by means of the union nut for sealing, in particular between opposite end faces.

[0025] The external thread can be an element of the detection system or can be an element, for example, of a sleeve (or flange), which can be arranged within the first opening and can be arranged in a vacuum-tight manner. The union nut can also be either an element of the detection system or, for example, an element of the aforementioned sleeve (or flange). The external thread together with the union nut can be designed, for example, as a bayonet lock. For this purpose, the external thread can have a special thread of a bayonet lock. By screwing the union nut onto the external thread, the detection system can be connected to the sample chamber in a detachable and, at the same time, vacuum-tight manner.The annular seal of the first sealing element can be arranged and compressed, for example, between an end face of an element of the detection system and an end face of a vacuum flange, for example, or a sleeve, to ensure a seal.

[0026] This allows the sample chamber to be detachably connected to the detection system in a simple and cost-effective manner.

[0027] According to one embodiment of the present invention, the connection system comprises a sleeve arranged within the first opening, wherein the at least one first sealing element comprises a further annular seal made of elastic material arranged between an inner surface of a region of the sample chamber wall delimiting the first opening and an outer surface region of the sleeve, wherein the sleeve is connected to the detection system in particular by means of the union nut screwed onto the external thread.

[0028] The sample chamber and the detection system can also be connected or connected by screwing flange elements, for example.

[0029] A longitudinal axis or an axis of the sleeve can essentially correspond to a propagation direction of the secondary radiation, which is detected by the detector when a specific angle of reflection is set. The further annular seal between the inner surface of a region of the sample chamber wall bounding the first opening and an outer surface region of the sleeve can create a vacuum-tight connection, but can also allow a certain relative mobility or elasticity or tolerance between the sample chamber and the detection system. This can enable tolerance compensation, in particular to limit mechanical stresses.

[0030] The annular seal of the first sealing element can allow for a mobility tolerance substantially in the axial direction of the sleeve. The further annular seal of the first sealing element, in contrast, can allow for a mobility tolerance between the detection system and the sample chamber in a direction perpendicular to the axial direction of the sleeve, particularly in a direction in which a torque acts when the detector is pivoted to change the recordable angle of incidence, resulting in a substantially synchronous entrainment of the sample chamber.

[0031] According to one embodiment of the present invention, the irradiation region has an opening angle of between 100° and 165°, furthermore in particular between 120° and 165°, even furthermore in particular between 140° and 165° and / or wherein the irradiation region is formed from X-ray permeable material, in particular plastic and / or beryllium and / or light metal and / or graphite and / or aluminum, wherein the irradiation region is formed in particular as a segment of a cylindrical surface, wherein a cylinder symmetry axis lies substantially in the goniometer axis.

[0032] The aperture angle of the transmission range can measure the angular extent of the transmission range, specifically the angular extent of the transmission range relative to the goniometer axis. For example, if measured in a Bragg-Brentano geometry, the aperture angle of the transmission range can correspond to twice the maximum angle of incidence, which can also correspond to twice the maximum angle of reflection. In the Bragg-Brentano geometry, both the radiation generation system and the detection system are pivoted in opposite directions by the same angle from a zero position.

[0033] The transmission area can, for example, be designed as a circular arc segment, with the arc segment having an angular extent between 100° and 165°. With an angular extent (or aperture angle) of 140°, for example, an angle of incidence of 70° and an angle of reflection of 70° can be achieved in the Bragg-Brentano geometry.

[0034] If the angular extent or aperture angle is even 165°, an angle of incidence of 82.5° and an angle of reflection of 82.5° can be achieved, for example, in the Bragg-Brentano geometry. This enables precise measurement of the sample.

[0035] The irradiation area can be made of a different material than other parts of the sample chamber wall, which can be made of steel, for example. Sealing elements, e.g., in the form of sealing lips, can be provided between the material of the irradiation area and the material of the sample chamber wall.

[0036] According to one embodiment of the present invention, the device comprises at least one of the following: a sample holder receptacle, in particular height-adjustable, which is designed to receive a sample holder; and / or a sample holder which can be held by means of the sample holder receptacle or a fixed base component and which is designed and arranged to hold the sample in the sample region.

[0037] The sample holder receptacle can be configured to accommodate various types of sample holders in order to hold them in a fixed position and orientation during the measurement. The sample holder receptacle can have a longitudinal axis that runs substantially along or collinear with the goniometer axis. A longitudinal direction of the sample holder receptacle can be finely adjustable in its position and / or coarsely adjustable, for example, to adjust a height or enable adjustment in another lateral direction. The sample holder receptacle can in turn be part of a base component or can be mounted on a base component, in particular a fixed base component.

[0038] One or more sample holders can be provided, in particular to support different types of samples. The sample holder can, for example, comprise a capillary to contain a liquid sample. The sample can be a solid, a powder, polycrystalline, crystalline, can be a liquid and / or can comprise a single crystal. The sample holder itself can, but does not have to, be height-adjustable or laterally adjustable. The sample holder can, for example, comprise a sample container (for example for a liquid and / or a powder) or can, for example, comprise a substrate or a flat element on which a solid sample can be fixed. Thus, different sample types are supported. In particular, the sample holder receptacle or the sample holder can be held in a fixed position and orientation during the measurement.

[0039] According to one embodiment of the present invention, the sample chamber comprises a second opening through which a fixed base component and / or the sample holder receptacle and / or the sample holder extends at least partially, wherein the device further comprises at least one second sealing element, in particular annular, made of elastic material, which is arranged between an outer surface region of the base component and / or the sample holder receptacle and / or the sample holder and an inner surface region of the sample chamber wall delimiting the second opening for sealing purposes, wherein the sample chamber is in particular removable.

[0040] The sample chamber can be rotatably (and vacuum-tightly) connected to the stationary base component and / or the sample holder receptacle via the second opening. A sample holder receptacle can, for example, extend partially or completely through the second opening into the sample chamber, so that the sample holder receptacle or the sample holder is arranged in the sample area, or such that the sample located on or in the sample holder is held in the sample area.

[0041] The second sealing element can be arranged substantially concentrically to the goniometer axis and can enable a vacuum-tight connection between the base component and / or the sample holder receptacle and / or the sample holder on the one hand and the vacuum chamber on the other, whereby a rotatable connection or coupling is achieved between the sample chamber on the one hand and the base component or the sample holder receptacle or the sample holder. When the sample chamber is pivoted, friction occurs between the inner surface region of the sample chamber wall delimiting the second opening and an outer surface of the second sealing element. In a contact region, for example, a lubricant, such as vacuum-compatible grease, can be provided in order to reduce frictional resistance and also to reduce abrasion. The second sealing element can enable a vacuum-tight connection and also rotatability of the sample chamber relative to the base component.The sample chamber may be removable, for example to mount a sample holder or a sample on the sample holder receptacle or in the sample holder or on the sample holder.

[0042] The second opening can, for example, be circular. Likewise, the second sealing element can be circular and arranged essentially concentrically to the goniometer axis. This enables sealing against air ingress and additionally allows the sample chamber to be rotated relative to the fixed base component.

[0043] According to one embodiment of the present invention, the annular seal and / or the further annular seal of the at least one first sealing element and / or the second sealing element is arranged concentrically and is circular and / or comprises at least one of the following: a lip seal, an O-ring, a shaft seal, or a sliding ring. The second sealing element can, in particular, be arranged concentrically to the goniometer axis. This supports various types of sealing elements, which can be selected depending on specific requirements.

[0044] According to one embodiment of the present invention, the device further comprises a bearing which is designed to rotatably support the sample chamber relative to the sample holder receptacle and / or sample holder and / or a fixed base component, wherein the bearing is exposed to the ambient pressure in particular outside the sample chamber.

[0045] The bearing can, for example, comprise a ball bearing, a plain bearing, a roller bearing, or a combination thereof. The bearing can hold the sample chamber in a defined geometric position and enable the sample chamber to be rotated relative to the stationary base component. In other embodiments, the device does not need to have such a bearing. If a bearing is provided, however, sealing can be improved because the second sealing element is not used exclusively for the intended or desired guidance of the sample chamber. Rather, guidance of the pivoting of the sample chamber is effected by the bearing. In particular, the bearing can thus ensure that the sample chamber, or in particular the second opening, always remains concentric with the goniometer axis during pivoting.

[0046] According to one embodiment of the present invention, the second sealing element is arranged between the bearing and the interior of the sample chamber. The bearing can thus be exposed to ambient pressure and located outside the sample chamber. The bearing can be lubricated without contaminating or degrading the vacuum in the interior of the sample chamber. Thus, conventional bearings can also be supported.

[0047] According to one embodiment of the present invention, the device further comprises: a first actuator configured to pivot the radiation generation system by means of the first goniometer arm; a second actuator configured to pivot the detection system together with the sample chamber connected thereto by means of the second goniometer arm, wherein the first actuator and / or the second actuator is arranged outside the sample chamber.

[0048] The actuators can, in particular, comprise electric motors, which can also comprise a gear, for example. The second actuator can be dimensioned in such a way that its applyable torque is not only capable of pivoting the detection system via the goniometer arm, but also of pivoting the connected sample chamber together with the detection system. The second actuator can exert a corresponding torque on the detection system via the goniometer arm, which, due to its connection to the sample chamber, can exert a torque on the sample chamber, so that the sample chamber pivots or rotates synchronously with the detection system when the second actuator is controlled accordingly. If the actuators are arranged outside the sample chamber, they can be exposed to ambient pressure and can therefore be designed conventionally.

[0049] According to one embodiment of the present invention, the radiation generation system is pivotable from a zero position (0°) by pivoting the first goniometer arm by up to between 60° and 82.5°, in particular up to between 70° and 82.5°, and / or wherein the detection system is pivotable from a zero position (0°) by pivoting the second goniometer arm by up to between 60° and 82.5°, in particular up to 70° and 82.5°, opposite to a pivoting direction of the radiation generation system.

[0050] This allows for angles of incidence and reflection between 60° and 82.5°, for example, and angles of reflection between 60° and 82.5°, for example, to be achieved, thus enabling comprehensive measurement of a sample. Conventional equipment for measuring samples using X-ray scattering can often only achieve smaller angles of incidence and reflection.

[0051] According to one embodiment of the present invention, the radiation generation system is arranged outside the sample chamber and exposed to ambient pressure, and / or wherein the radiation generation system comprises a radiation source and optics to generate the primary radiation with a predetermined wavelength range and / or predetermined cross-sectional size.

[0052] The radiation generation system can thus also be a conventional radiation generation system. The device can be configured, depending on requirements, to provide a specific wavelength range or a specific cross-sectional size and / or cross-sectional profile of the primary radiation. This supports various measurement variants or measurement methods.

[0053] According to one embodiment of the present invention, the device further comprises at least one vacuum connection on the sample chamber and / or on the detection system and / or at least one vacuum pump which is designed to generate a pressure of less than 30 mbar within the sample chamber and / or the detection beam path.

[0054] This allows for reliable evacuation of the sample chamber's interior. Using a vacuum pump, the pressure can be adjusted to between 2 mbar and 10 mbar within the sample chamber, or even between 1 mbar and 10 mbar. A diaphragm pump, for example, can be used as a vacuum pump.

[0055] A detector surface of one or more detector elements of the detection system can be evacuated as part of the detection beam path. In particular, no window needs to be provided in front of a detector surface of the detection system. Electronics or evaluation or readout electronics of the detection system can also be evacuated.

[0056] According to one embodiment of the present invention, the detection system comprises a detection optics and / or a filter and a detector, wherein the filter is arranged in the detection beam path, in particular at the first opening and / or the fastening element.

[0057] The filter can, for example, be provided to attenuate unwanted wavelengths or radiation of unwanted wavelengths before they impinge on a detection element or a sensor element, or to substantially reduce their intensity, for example, to between 0% and 10% of the intensity of the respective wavelength or wavelength range impinging on the filter. The filter can, for example, also be replaceable to enable application-specific filtering. The filter can be arranged at any location within the detection beam path, for example, within the aforementioned sleeve or in an input region of the detection system.

[0058] According to one embodiment of the present invention, the detector of the detection system comprises a two-dimensional or three-dimensional array of detector elements used as a point detection system or a line detection system.

[0059] The detector elements can, for example, comprise CCD detector elements and / or CMOS detector elements. Evaluation software or evaluation electronics can interconnect or be configured to combine intensity signals originating from multiple detector elements, for example, to determine an integral recorded intensity.

[0060] According to one embodiment of the present invention, the device further comprises a controller which is communicatively connected to the radiation generation system and / or the first actuator and / or the detection system and / or the second actuator and / or the vacuum pump for carrying out a measurement in order to transmit control signals and / or receive measurement signals.

[0061] The control can be implemented, for example, in software and / or hardware. Various programs can be provided and available to perform different measurement methods.

[0062] According to one embodiment of the present invention, the device is designed to carry out at least one of the following measuring methods: X-ray diffraction (XRD), in particular in Bragg-Brentano geometry, X-ray fluorescence analysis (XRF), small angle X-ray diffraction (SAXS), in each case in reflection and / or transmission, and / or wherein the goniometer axis runs substantially horizontally or vertically, and / or wherein the sample comprises a powder and / or a crystal and / or many crystals and / or a liquid, and is immobile during the measurement, and / or wherein the sample chamber is substantially cylindrical.

[0063] This enables comprehensive investigations of a wide variety of samples. This allows, for example, elemental analysis or the analysis of chemical compounds. The sample chamber, which can be essentially cylindrical, can have its cylinder axis aligned substantially with the goniometer axis. This allows for simple manufacturing of the sample chamber.

[0064] It should be understood that features mentioned, explained, provided or employed alone or in any combination in connection with an apparatus for examining a sample by means of X-ray radiation may also be applied, individually or in any combination, to an evacuable sample chamber for an apparatus for examining a sample by means of X-ray radiation and vice versa, according to embodiments.

[0065] According to one embodiment, an evacuable sample chamber is provided for a device for examining a sample using X-rays. The sample chamber has a sample chamber wall that delimits a sample chamber interior, within which the sample can be arranged in a sample region, wherein the sample chamber wall has a vacuum-tight X-ray transmission region that is permeable to the X-rays and allows the X-rays to penetrate into the sample chamber and strike the sample region at different angles of incidence. The sample chamber has a first opening, e.g., in a detection beam path, at which the sample chamber and a detection system can be connected in a vacuum-tight manner, in particular by means of a connection system having a first sealing element, such that the detection beam path can be evacuated.The sample chamber has a second opening and, in particular, a second sealing element that can be arranged for sealing purposes at an inner surface region of the sample chamber wall that delimits the second opening. The irradiation region has an opening angle of between 100° and 165°, in particular between 120° and 165°, and furthermore, in particular between 140° and 165°, wherein the irradiation region is formed, in particular, as a segment of a cylindrical surface.

[0066] The invention will now be explained with reference to the accompanying drawings. The invention is not limited to the illustrated or described embodiments. Short description of the drawing

[0067] Fig. 1A, 1B, 1C illustrate schematically an apparatus for examining a sample by means of X-ray radiation according to an embodiment of the present invention in a reference configuration or zero configuration; Fig. 2A, 2B, 2Cillustrate schematically the Fig. 1A, 1B, 1C illustrated device in another configuration during a measurement; Fig. 3 schematically illustrates in a sectional view connecting elements for connecting a base component to the sample chamber; Fig. 4 illustrates schematically in a sectional view connecting elements for connecting a detection system to a sample chamber, as used in Fig. 1A, 1B, 1C , 2A, 2B, 2C illustrated device can be used. Detailed description

[0068] In Fig. 1A , 2A the device 1 for examining a sample by means of X-ray radiation according to an embodiment of the present invention is schematically illustrated in a side view along an x-axis of a coordinate system, in Fig. 1B , 2B the device 1 is shown in a plan view along the z-axis of the coordinate system and in Fig. 1C , 2Cthe device 1 is schematically illustrated in a perspective three-dimensional representation, each in two different measuring positions or measuring configurations.

[0069] The device 1 comprises a radiation generation system 2 for generating primary radiation 3. The device 1 further comprises a first goniometer arm 4, on which the radiation generation system 2 is mounted and which is pivotable about a goniometer axis 5. The device 1 further comprises a detection system 6, which is designed to detect secondary radiation 7 emanating from the sample. The device 1 further comprises a second goniometer arm 8, on which the detection system 6 is mounted and which is pivotable about the goniometer axis 5. The device 1 further comprises an evacuable sample chamber 9, within which a sample 10 can be arranged in a sample region 11 comprising part of the goniometer axis.The sample chamber 9 is delimited by a sample chamber wall 12, wherein the sample chamber wall 12 has a vacuum-tight transmission region 13 which is permeable to the primary radiation 3 in order to enable the primary radiation 3 to penetrate into the sample chamber 9 and to strike the sample region 11 at different angles of incidence θ_ein. In the in . Fig. 1A, 1B, 1C illustrated reference configuration or reference position or zero position, the angle of incidence is θ_ein=0°, while the angle of incidence in the Fig. 2A, 2B, 2C illustrated measurement configuration or measurement position is not equal to zero and is approximately 45°.

[0070] The sample chamber 9 has a first opening 15 in a detection beam path 14, at which opening the sample chamber 9 and the detection system 6 can be connected in a vacuum-tight manner, so that the detection beam path 14 can be evacuated. The device 1 further has a connection system 16, which is designed for the detachable, vacuum-tight, in particular elastic, connection of the sample chamber 9 to the detection system 6 at the first opening 15.

[0071] The connection system 16 is in Fig. 4 illustrated in greater detail in a cross-sectional view through a YZ plane. On the left side, the Fig. 4 a part of the sample chamber 9 is illustrated and on the right side a part of the detection system 6 is illustrated.

[0072] The connection system 16 has an external thread 19 and a union nut 20, and a first sealing element has an annular seal 21 made of elastic material, which can be compressed by means of the union nut 20 for sealing, namely between opposite end faces 22 and 23.

[0073] The sample chamber 9 has the first opening 15. A sleeve 17 is arranged within the first opening 15. In the illustrated embodiment, the end face 22 is an end face or flange surface of a flange 40 of the sleeve 17. The end face 23 is a part or element associated with the detection system 6. When the union nut 20 is screwed onto the external thread 19, the flange surface 22 or end face 22 of the sleeve 17 is pressed against the annular seal 21, thus creating a vacuum-tight connection. The union nut 20 engages a rear surface of the flange 40 of the sleeve 17.

[0074] A further annular seal 24 (belonging to a first sealing element of the connection system 16) is arranged between an inner surface of a region of the sample chamber wall 12 defining the first opening and an outer surface region 18 of the sleeve 17. The sleeve 17 can be connected to the detection system 6 by means of the union nut 20 screwed onto the external thread 19.

[0075] The detection beam path 14 extends through the sleeve 17 to strike a detector element 25 of the detection system 6, which is sensitive to the secondary radiation 7, and to be registered there with regard to its intensity. The entire detection beam path 14 and, in particular, the detection element 25 of the detection system are evacuated from ambient pressure, as are the entire sample chamber or the interior of the sample chamber 9.

[0076] The transmission area 13 has an opening angle a, which can, for example, be between 0° and 165°. The transmission area 13 seals the sample chamber 9 vacuum-tight but is permeable to X-rays, i.e., it exhibits relatively low absorption for X-rays.

[0077] The device further comprises a sample holder mount 26. The sample holder mount 26 can be height-adjustable, i.e., its position can be adjusted along the Z-axis. The sample holder mount allows a sample holder 27 to be held, on which or on which a sample 10 can be mounted or held.

[0078] The sample chamber 9 has a second opening 27 through which a fixed base component 31 and / or the sample holder receptacle 26 and / or a sample holder 27 extends at least partially. The goniometer arms 4 and 8 are pivotable relative to the base component 31, as well as relative to the sample holder receptacle 26.

[0079] Fig. 3 Illustrates, in a schematic sectional view of a section through the XY plane, a portion of the sample chamber 9, which has the sample chamber wall 12, as well as a portion of the base component 31, relative to which the sample chamber 9 is pivotable. A second sealing element 29 for sealing is arranged between an outer surface region of the base component 28 and an inner surface region of the sample chamber wall 12, which delimits the second opening 28. The second sealing element 29 can, for example, have a lip seal.

[0080] Furthermore, a bearing 30 is provided, which is designed to rotatably support the sample chamber 9 relative to the sample holder receptacle and / or the stationary base component 31. A sample chamber interior 32 within the sample chamber 9 is evacuatable. However, the bearing 30 is arranged outside the sample chamber 9, i.e., outside the interior 32 of the sample chamber 9, and is thus exposed to the ambient pressure. The second sealing element 29 is thus arranged between the bearing 30 and the sample chamber interior 32.

[0081] A first actuator 33 (see Fig. 1A to 2C) is designed to pivot the radiation generation system 2 by means of the first goniometer arm 4. A second actuator 34 is designed to pivot the detection system 6 together with the sample chamber 5 connected thereto by means of the second goniometer arm 8. Both actuators 33, 34 are arranged outside the sample chamber 9. By means of the actuator 33 and the first goniometer arm 4, the radiation generation system 2 can be pivoted by up to between 60° and 82.5° in order to be able to adjust an angle of incidence θ_ein within this range as required.

[0082] Similarly, the detection system 6 can be pivoted by up to 60° and 82.5° by pivoting the second goniometer arm 8 (by means of the second actuator 34), in order to be able to adjust an angle of incidence θ_out in this range as required.

[0083] The sample chamber 9 and / or the detection system 6 may have a vacuum connection (not illustrated in detail) to which a vacuum pump may be connectable in order to generate a pressure of <30 mbar in the sample chamber interior 32.

[0084] The detection system 6 may comprise a detection optics and / or a filter 35, which, for example, Fig. 4 and is arranged in front of the detection element 25 of the detection system 6 in the propagation direction of the secondary radiation 7. The filter 35 can thus be arranged near the fastening element 16 or, for example, also within the sleeve 17.

[0085] The device 1 further comprises a controller 36 which, for carrying out a measurement, is communicatively connected to the radiation generation system 2, the first actuator 33, the detection system 6, the second actuator 34 and to a vacuum pump (not illustrated) in order to transmit control signals and / or to receive and evaluate measurement signals.

[0086] In the illustrated embodiment, the goniometer axis 5 runs in the horizontal direction.

[0087] The Fig. 1A, 1B, 1C , 2A, 2B, 2CThe device illustrated is manufactured according to a method of the present invention. The radiation generation system 2 is mounted on the first goniometer arm 4. Furthermore, the detection system 6 is mounted on the second goniometer arm 8. Furthermore, the evacuable sample chamber 9 is provided, which has a vacuum-tight irradiation region 13 that is permeable to primary radiation. Furthermore, the sample chamber is manufactured such that it has a first opening 15 in a detection beam path 14, at which opening the sample chamber and the detection system can be connected in a vacuum-tight manner, in particular by means of the connection system 16.

[0088] Embodiments of the present invention may include one or more of the following features: 1. X-ray diffraction Bragg-Brentano diffractometer (XRD) with an angular accuracy of 1 / 10000° a. The diffractometer has a horizontal goniometer axis. However, it is also possible to have a diffractometer with a vertical goniometer axis. b. The device can also be converted for X-ray fluorescence analysis (XRF). 2. Goniometer unit with radiation source a. The radiation source is located outside the vacuum chamber on a goniometer arm. b. The X-ray source rotates via the goniometer arm during the measurement. Therefore, the vacuum chamber has a large window (approx. 160°) so that the radiation can hit the sample at the correct angle. c. The X-ray source can be a Cu-K(alpha) source; the anode material can also be Cr, Fe, Co, Cu, Mo, Ag d. The window is made of plastic or beryllium; beryllium is avoided because beryllium compounds are toxic. 3. Sample a. The sample can be a powder, crystal, or a liquid in a capillary. b.The sample is in a vacuum chamber. c. The sample is positioned on the sample stage at the position of the goniometer axis. d. The sample can be adjusted in height before the measurement for more precise positioning. e. The sample does not change position during the measurement. 4. Unit goniometer with detector with vacuum chamber a. The detector goniometer arm is fixedly connected to the vacuum chamber via a detachable connection. This means that the detector is also fixedly connected to the vacuum chamber. If the detector goniometer rotates, the vacuum chamber also rotates. b. There is therefore no window between the sample and detector. Windows attenuate or scatter the beam from the sample and increase the background signal, which degrades the measurement signal. Window materials with little attenuation are problematic, e.g. beryllium is toxic. c. The vacuum chamber and the detector are in the same vacuum. Air scatters or scatters.attenuates the beam; the less air, the better the signal. The vacuum chamber and detector are evacuated simultaneously (weak vacuum, 1-10 mbar). d. The vacuum connection can be located on the vacuum chamber and / or near the detector. e. There are two connections for the vacuum, so the chamber can be filled or purged with inert gas. f. The vacuum chamber is rotatably mounted (bearing diameter approx. 12 cm) and the bearing is vacuum-tight (sliding rotating seal). g. Since the detector is also in a vacuum, the detector connections must be vacuum-tight. h. Because the goniometer also rotates the vacuum chamber, the goniometer and the goniometer drive are designed to be more powerful (higher torque) than normal (special safety measures are in place for this). This is also necessary to ensure the necessary precision. i. The detector is flanged to the vacuum chamber. This means that the vacuum chamber can also be removed if necessary for the measurement.j. The flange connection between the detector and the vacuum chamber is elastic to compensate for small differences. k. The detector is a 256 x 256 pixel detector, which is used as a point detector.

[0089] The device for examining a sample has a simple design and enables measurements over a wide angular range. There is no need for windows or air in the detection beam path between the sample and the detector, so that the signal from the sample is not unnecessarily attenuated. The detector goniometer can be supported on two bearings: once via the conventional goniometer bearing (without a seal) and the second via the bearing near the vacuum chamber (with a rotating lip seal). The detector and detector goniometer are connected to each other with a flange; this connection is designed to compensate for tolerances. This connection is detachable and has a vacuum seal that is subject to minimal movement. The drive of the second goniometer arm 8 is more powerful than conventional ones, since this second actuator 34 must also rotate the sample chamber or vacuum chamber 9.

[0090] Since there is no window between the sample and the detector in the invention, the beam stop is unnecessary. Modern detectors are not damaged by the incident primary X-ray beam and are partially capable of measuring the primary intensity. This enables better measurement results, as no scattering from the beam stop influences the measurement result.

[0091] The vacuum-tight sample chamber can be rigidly connected to the vacuum-tight housing for the optics and the detection system. The vacuum-tight sample chamber can be mounted on a vacuum rotary feedthrough (as in Fig. 3 illustrated). The vacuum rotary union can be mounted on a mounting flange 37 (e.g. part of the base component 31, see Fig. 3 ) which is arranged so that the vacuum rotary feedthrough is concentric with the goniometer axis 5.

[0092] If the pivot angle of the detection system 6 is changed (change of θ_off), the vacuum-tight sample chamber 9 rotates with it. The transmission area or the entrance window 13 on the sample chamber 9 can, for example, cover the largest possible angular range so that the measurable angular range is not restricted. The fastening system 16 is provided in the detection beam path 14, which runs through the first opening 15 of the sample chamber, to connect the vacuum-tight sample chamber 9 to the vacuum-tight optics housing of the detection system 6 in front of the optics. This ensures that there is no window or air gap behind the sample, which is located on the axis of the X-ray diffractometer. A filter 35 can also be optionally integrated into the fastening system 16 or the fastening element, for example to suppress or attenuate the Kβ radiation from a copper X-ray source using nickel foil.

Claims

1. A device (1) for examining a sample (10) by means of X-ray radiation, comprising: a radiation generating system (2) for generating primary radiation (3); a first goniometer arm (4) at which the radiation generating system (2) is mounted and which is pivotable about a goniometer axis (5); a detection system (6) which is configured for detecting secondary radiation (7) emanating from the sample; a second goniometer arm (8) at which the detection system (6) is mounted and which is pivotable about the goniometer axis (5); an evacuable sample chamber (9), within which the sample (10) can be arranged in a sample region (11) encompassing a part of the goniometer axis, wherein the sample chamber (9) is delimited by means of a sample chamber wall (12) which comprises a radiation transmission region (13) which is permeable to the primary radiation (3) and is vacuum-tight, in order to enable the primary radiation (3) to penetrate into the sample chamber (9) and to be able to impinge on the sample region (11) at different angles of incidence (θ_in); wherein the sample chamber (9) comprises, in a detection beam path (14), a first opening (15) at which the sample chamber (9) and the detection system (6) can be connected in a vacuum-tight manner, such that the detection beam path (14) can be evacuated, wherein the radiation transmission region (13) closes the sample chamber (9) in a vacuum-tight manner, wherein the radiation transmission region (13) comprises an opening angle of between 100° and 165°, wherein the opening angle of the radiation transmission region measures the angular extent of the radiation transmission region with respect to the goniometer axis.

2. The device according to the preceding claim, further comprising: a connecting system (16) which is configured for a releasable vacuum-tight, in particular elastic or rigid, connection of the sample chamber (9) to the detection system (6) at the first opening (15), wherein the connecting system comprises at least one first sealing element (21, 24), wherein the first opening (15) is in particular circular or rectangular.

3. The device according to the preceding claim, wherein the connecting system (16) comprises an external thread (19) and a union nut (20), wherein the at least one first sealing element comprises an annular seal (21) made of elastic material which can be pressed by means of the union nut (20) for sealing, in particular between opposite end faces (22, 23).

4. The device according to one of the two preceding claims 2 or 3, wherein the connecting system (16) comprises a sleeve (17) which is arranged within the first opening (15), wherein the at least one first sealing element comprises a further annular seal (24) made of elastic material which is arranged between an inner surface of a region of the sample chamber wall (12) delimiting the first opening and an outer surface region of the sleeve (17), wherein the sleeve (17) is connected to the detection system (6) in particular by means of the union nut (20) screwed onto the external thread (19).

5. The device according to one of the preceding claims, wherein the radiation transmission region (13) comprises an opening angle of between 120° and 165°, in particular between 140° and 165°, and / or wherein the radiation transmission region (13) is formed from material which is permeable to X-ray radiation, in particular comprising plastic and / or beryllium and / or light metal and / or graphite and / or aluminum, wherein the radiation transmission region (13) is formed in particular as a segment of a cylinder lateral surface, wherein a cylinder symmetry axis lies substantially in the goniometer axis (5).

6. The device according to one of the preceding claims, further comprising at least one of the following: a sample holder reception (26), in particular height-adjustable, which is configured to receive a sample holder; and / or a sample holder (27), in particular height-adjustable, which can be held by means of the sample holder reception or a stationary base component and which is configured and arranged to hold the sample in the sample region (11).

7. The device according to one of the preceding claims, wherein the sample chamber (9) comprises a second opening (28) through which a stationary base component (31) and / or the sample holder reception (26) and / or the sample holder (27) at least partially extends, wherein the device further comprises at least one second sealing element (29), in particular annular, made of elastic material which is arranged between an outer surface region of the base component (31) and / or the sample holder reception and / or the sample holder and an inner surface region of the sample chamber wall delimiting the second opening for sealing, wherein the sample chamber is in particular removable.

8. The device according to one of the preceding claims, wherein the annular seal (21) and / or the further annular seal (24) of the at least one first sealing element and / or the second sealing element (29) is arranged concentrically and is circular and / or comprises at least one of the following: a lip seal, an O-ring, a shaft seal, a sliding ring.

9. The device according to one of the preceding claims, further comprising: a bearing (30) which is configured for rotatably supporting the sample chamber (9) relative to the sample holder reception and / or sample holder and / or a stationary base component (31), wherein the bearing is in particular exposed to the ambient pressure outside the sample chamber, in particular wherein the second sealing element (29) is arranged between the bearing (30) and a sample chamber interior (32).

10. The device according to one of the preceding claims, further comprising: a first actuator (33) which is configured for pivoting the radiation generating system (2) by means of the first goniometer arm (4); a second actuator (34) which is configured for pivoting the detection system (6) together with the sample chamber (9) connected thereto by means of the second goniometer arm (8), wherein the first actuator and / or the second actuator is arranged outside the sample chamber.

11. The device according to one of the preceding claims, wherein the radiation generating system (2) is pivotable by means of pivoting the first goniometer arm (4) by up to between 60° and 82.5°, in particular up to between 70° and 82.5°, from a zero position (0°) and / or wherein the detection system (6) is pivotable by means of pivoting the second goniometer arm (8) by up to between 60° and 82.5°, in particular up to 70° and 82.5°, from a zero position (0°) opposite to a pivoting direction of the radiation generating system; and / or wherein the radiation generating system (2) is arranged outside the sample chamber and is exposed to ambient pressure, and / or wherein the radiation generating system (2) comprises a radiation source and optics for generating the primary radiation with a predetermined wavelength range and / or a predetermined cross-sectional size.

12. The device according to one of the preceding claims, further comprising: at least one vacuum connection at the sample chamber and / or at the detection system; at least one vacuum pump configured to generate a pressure of less than 30 mbar within the sample chamber and / or the detection beam path; and / or wherein the detection system (6) comprises a detection optical unit and / or a filter (35) and a detector (25), wherein the filter (35) is arranged in the detection beam path (14), in particular at the first opening (15) and / or the fastening element (16).

13. The device according to one of the preceding claims, wherein the detector (25) of the detection system (6) comprises a two-dimensional or three-dimensional array of detector elements which are used as a point detection system or row detection system; and / or wherein the device further comprises a controller (36) which is communicatively connected to the radiation generating system and / or the first actuator and / or the detection system and / or the second actuator and / or the vacuum pump for carrying out a measurement in order to transmit control signals and / or to receive measurement signals.

14. The device according to one of the preceding claims, wherein the device is configured to carry out at least one of the following measurement methods: X-ray diffraction (XRD), in particular in Bragg-Brentano geometry, X-ray fluorescence analysis (XRF), small-angle X-ray diffraction (SAXS), respectively in reflection and / or transmission, and / or wherein the goniometer axis (5) runs substantially horizontally or vertically, and / or wherein the sample (10) comprises a powder and / or a crystal and / or many crystals and / or a liquid, and is immovable during the measurement, and / or wherein the sample chamber (9) is substantially cylindrical.

15. The device according to one of the preceding claims, wherein the sample chamber (9) comprises: a second opening (28); in particular a second sealing element (29) which can be arranged at an inner surface region of the sample chamber wall delimiting the second opening for sealing, wherein the radiation transmission region (13) is formed in particular as a segment of a cylinder lateral surface.