Delivery, installation and commissioning of a universal X-ray diffractometer for small-angle X-ray scattering (SAXS), micro-X-ray diffractometry (μXRD) and X-ray powder diffractometry (PXRD) including a sample table for in-situ measurements

The object of service is the delivery and commissioning of a universal X-ray diffractometer with a standing goniometer and theta-theta configuration. The goniometer must have an accuracy of 0.01° or better, with a reproducibility of at least +/- 0.0002°. The angle range that can be traveled must be at least from -100° to 165° 2 theta. The device must be a complete protection device according to StrSchV with type approval (BAZ) and fulfill the following measurement tasks: X-ray powder diffractometry (PXRD), micro X-ray diffractometry (µXRD), small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS). The components for the various measuring tasks should largely remain in the device when not in use, which is why a large radiation protection housing in a fully protective design is required (minimum interior dimensions 1300 mm x 1000 mm) .The conversion between the device configurations must be carried out by trained laboratory personnel.

The device is intended to allow an adjustment-free exchange of the optical modules, sample carriers and detectors. All components should be automatically recognized by the system. The X-ray source must be a long-fine focus tube that can be changed by the user. The tube should be able to be operated with at least 50 kV (Ag tubes) for a short time. Cu and Ag are to be used as anode materials, whereby the device must be equipped with Cu tubes for initial use. The Ag tube is intended to be used primarily for PDF analyses. When changing PXRD and µXRD, the tube must be able to be switched from line focus to point focus without interrupting the cooling water circuit.

The primary optics must contain all components that are necessary for the various measurement tasks. These include corresponding k filters, target diaphragms, masks, attenuators and, above all, a motorized and automated divergence diaphragm for operation with a constantly irradiated sample surface as well as with a constant aperture. A focusing mirror for Cu radiation must also be present in the primary optics. All primary diaphragms should preferably be programmable. In the µXRD configuration, the primary beam must be focused on focal spot sizes of 0.1 mm, 0.3 mm and 0.5 mm or be able to be conditioned as a parallel beam. This can be done with monocapillaries or motorized diaphragms. Furthermore, it should be possible to limit the primary beam only with the aid of masks. PDF analyses require the use of hard radiation (Ag, Mo). Suitable filters, attenuators and diaphragms (for automatic iris or fixed aperture) must be included for hard radiation operation. The tube must be able to be replaced quickly and by laboratory personnel. For SAXS measurements, the primary optics are needed to extend corresponding components with which high-resolution transmission measurements are possible.

The secondary optics include the detectors as well as the associated anti-scatter diaphragms and setter diaphragms. All secondary diaphragms should preferably be programmable. A 2D pixel detector will be used for SAXS, WAXS and µXRD experiments. At least one detector must be suitable for the use of hard radiation. For SAXS measurements, both optimal angular resolution and minimizing air scattering are essential. It is therefore important to measure with the smallest possible pixel size and small measuring circle radii. The pixel size of the 2D detector should be as small as possible for a good resolution of the SAXS signals and may not exceed 75 µm. The angular resolution with a fixed detector and 280 mm measuring circle radius must be ≤ 0.015°. At least one collimator must be available for beam focusing. In order to avoid overradiation at low Q values, a beam stop must be present for the SAXS experiments.

An energy-dispersive line detector (1D detector) is to be used for powder diffractometry. The latter must be able to mask out spectral artifacts of the X-ray tube, such as the K line of the anode material, without a solid-state filter (metal foils). Furthermore, the detector must discriminate against interfering Fe fluorescence of the sample when using Cu radiation. It must also be possible to use this discrimination to use the K line of the respective tube anode instead of the usual use of the K lines. The energy resolution of the 1D detector must be ≤ 380 eV for Cu-K radiation. The efficiency of the Cu-K radiation detector must be ≥ 94%.

Both the primary optics and the secondary optics must be configurable for grazing incident measurements (GIXRD). This relates to the primary-side beam parallelization and to a secondary-side axial setpoint orifice.

Depending on the measurement configuration, different sample stages and sample feeds must be used. For standard powder diffractometry, the instrument must have a programmable automatic sample changer with at least 45 positions and a sample stage with rotation function. The sample stage must be usable both for reflection and for transmission measurements. The rotation speed of the sample should be programmable between standstill and at least 1 rpm.

For the µXRD measurements, a programmable sample stage must be available that can be moved electrically in all spatial directions (x y z sample stage). The maximum sample height should be at least 50 mm. A device must be provided to fix samples on the table. A camera and a laser positioning system must be available for sample positioning. The image acquisition by the camera should be integrated into the software and used to control the x-y-z table.

In order to minimize air scattering and thus unnecessary noise in low-scattering samples, it must be possible to evacuate as much of the beam guidance as possible (vacuum) in the SAXS configuration. For this purpose, special evacuable chambers or tubes must be provided. A vacuum pump must be supplied for evacuation. The test recording must be done with the help of capillaries. For this purpose, a suitable capillary holder must be able to be installed in the device. Different specimen holders must be offered. These include standard holders for powder samples in various sizes (30 pieces large, 15 pieces small), sample holders for thicker solid samples (15 pieces), sample holders for wet samples (kapton film cover) (3 pcs.), sample holders with low substrate (e.g. Si single crystal) (2 pcs) and sample holders for oriented clay mineral preparations (10 pcs.) as well as special tools for preparation. In addition, sample holders for measurement under exclusion of air are to be offered, which can be prepared in the glove box.

The computer for controlling the diffractometer must have current hardware components, at least one Intel Core i5 8.gernation or comparable CPU as CPU and 8 GB of memory. The operating system must be installed in German, as a 64-bit version. In addition to any manufacturer-related assignment of external connections, at least 3 USB 3.0 ports must be freely available for use, as well as a free RJ 45 connection with at least 100 Mbit for connection to the in-house network.

Phase identification software must be included, with sufficient licenses for simultaneous use by at least 10 users. The software must be able to use the Crystallography Open Database (COD) for phase search, in addition PDF 2 (version 2003) and the PDF4/4+ database. A multi-year license for the PDF4+ database can be offered as an option. In addition, the software must enable the creation of a user database for searching, and enable the import of CIF files into the user database. In addition to the manufacturer's own scan data format, the software must also be able to import data in text format. The software should also make it possible to transfer the positively identified phases from suitable databases in the form of structure files to the software mentioned below for Rietveld refinement for direct use.

Appropriate software must be supplied for evaluation by means of Rietveld refinement, for quantifying the phase stock and for refining crystal structures. This must also be usable by at least 10 users at the same time. The software must offer functions for determining X-ray amorphous components using internal and external standards. The software must also have functions in order to calibrate peak lists in summary as a phase or to be able to use phases for quantification on the basis of the symmetry framework alone (PONKCS approach).

To evaluate the SAXS experiments, appropriate software must be supplied that allows particle size distributions and the specific surface area to be calculated. Ready-made analysis methods (Guinier or Porod) as well as adaptation methods and simulation methods must already be available.

For device cooling or connection to in-house cooling, a device with a water-cooled evaporator (water-water cooler) must be provided.

A temperature-controlled sample table is to be delivered and installed for measurements of hydration processes. The entire unit consists of a controller unit for measuring and controlling the temperature of the sample and a sample table, which must be temperature-controllable with a Peltier element. It must be possible to drive temperature profiles. The control system must be accessible with the included software. The in-situ measuring cell is advertised as a second lot. The main device manufacturer must provide the appropriate interfaces and adapters.

The object of service is the delivery and commissioning of a universal X-ray diffractometer with a standing goniometer and theta-theta configuration. The goniometer must have an accuracy of 0.01° or better, with a reproducibility of at least +/- 0.0002°. The angle range that can be traveled must be at least from -100° to 165° 2 theta. The device must be a complete protection device according to StrSchV with type approval (BAZ) and fulfill the following measurement tasks: X-ray powder diffractometry (PXRD), micro X-ray diffractometry (µXRD), small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS). The components for the various measuring tasks should largely remain in the device when not in use, which is why a large radiation protection housing in a fully protective design is required (minimum interior dimensions 1300 mm x 1000 mm) .The conversion between the device configurations must be carried out by trained laboratory personnel.

The device is intended to allow an adjustment-free exchange of the optical modules, sample carriers and detectors. All components should be automatically recognized by the system. The X-ray source must be a long-fine focus tube that can be changed by the user. The tube should be able to be operated with at least 50 kV (Ag tubes) for a short time. Cu and Ag are to be used as anode materials, whereby the device must be equipped with Cu tubes for initial use. The Ag tube is intended to be used primarily for PDF analyses. When changing PXRD and µXRD, the tube must be able to be switched from line focus to point focus without interrupting the cooling water circuit.

The primary optics must contain all components that are necessary for the various measurement tasks. These include corresponding k filters, target diaphragms, masks, attenuators and, above all, a motorized and automated divergence diaphragm for operation with a constantly irradiated sample surface as well as with a constant aperture. A focusing mirror for Cu radiation must also be present in the primary optics. All primary diaphragms should preferably be programmable. In the µXRD configuration, the primary beam must be focused on focal spot sizes of 0.1 mm, 0.3 mm and 0.5 mm or be able to be conditioned as a parallel beam. This can be done with monocapillaries or motorized diaphragms. Furthermore, it should be possible to limit the primary beam only with the aid of masks. PDF analyses require the use of hard radiation (Ag, Mo). Suitable filters, attenuators and diaphragms (for automatic iris or fixed aperture) must be included for hard radiation operation. The tube must be able to be replaced quickly and by laboratory personnel. For SAXS measurements, the primary optics are needed to extend corresponding components with which high-resolution transmission measurements are possible.

The secondary optics include the detectors as well as the associated anti-scatter diaphragms and setter diaphragms. All secondary diaphragms should preferably be programmable. A 2D pixel detector will be used for SAXS, WAXS and µXRD experiments. At least one detector must be suitable for the use of hard radiation. For SAXS measurements, both optimal angular resolution and minimizing air scattering are essential. It is therefore important to measure with the smallest possible pixel size and small measuring circle radii. The pixel size of the 2D detector should be as small as possible for a good resolution of the SAXS signals and may not exceed 75 µm. The angular resolution with a fixed detector and 280 mm measuring circle radius must be ≤ 0.015°. At least one collimator must be available for beam focusing. In order to avoid overradiation at low Q values, a beam stop must be present for the SAXS experiments.

An energy-dispersive line detector (1D detector) is to be used for powder diffractometry. The latter must be able to mask out spectral artifacts of the X-ray tube, such as the K line of the anode material, without a solid-state filter (metal foils). Furthermore, the detector must discriminate against interfering Fe fluorescence of the sample when using Cu radiation. It must also be possible to use this discrimination to use the K line of the respective tube anode instead of the usual use of the K lines. The energy resolution of the 1D detector must be ≤ 380 eV for Cu-K radiation. The efficiency of the Cu-K radiation detector must be ≥ 94%.

Both the primary optics and the secondary optics must be configurable for grazing incident measurements (GIXRD). This relates to the primary-side beam parallelization and to a secondary-side axial setpoint orifice.

Depending on the measurement configuration, different sample stages and sample feeds must be used. For standard powder diffractometry, the instrument must have a programmable automatic sample changer with at least 45 positions and a sample stage with rotation function. The sample stage must be usable both for reflection and for transmission measurements. The rotation speed of the sample should be programmable between standstill and at least 1 rpm.

For the µXRD measurements, a programmable sample stage must be available that can be moved electrically in all spatial directions (x y z sample stage). The maximum sample height should be at least 50 mm. A device must be provided to fix samples on the table. A camera and a laser positioning system must be available for sample positioning. The image acquisition by the camera should be integrated into the software and used to control the x-y-z table.

In order to minimize air scattering and thus unnecessary noise in low-scattering samples, it must be possible to evacuate as much of the beam guidance as possible (vacuum) in the SAXS configuration. For this purpose, special evacuable chambers or tubes must be provided. A vacuum pump must be supplied for evacuation. The test recording must be done with the help of capillaries. For this purpose, a suitable capillary holder must be able to be installed in the device. Different specimen holders must be offered. These include standard holders for powder samples in various sizes (30 pieces large, 15 pieces small), sample holders for thicker solid samples (15 pieces), sample holders for wet samples (kapton film cover) (3 pcs.), sample holders with low substrate (e.g. Si single crystal) (2 pcs) and sample holders for oriented clay mineral preparations (10 pcs.) as well as special tools for preparation. In addition, sample holders for measurement under exclusion of air are to be offered, which can be prepared in the glove box.

The computer for controlling the diffractometer must have current hardware components, at least one Intel Core i5 8.gernation or comparable CPU as CPU and 8 GB of memory. The operating system must be installed in German, as a 64-bit version. In addition to any manufacturer-related assignment of external connections, at least 3 USB 3.0 ports must be freely available for use, as well as a free RJ 45 connection with at least 100 Mbit for connection to the in-house network.

Phase identification software must be included, with sufficient licenses for simultaneous use by at least 10 users. The software must be able to use the Crystallography Open Database (COD) for phase search, in addition PDF 2 (version 2003) and the PDF4/4+ database. A multi-year license for the PDF4+ database can be offered as an option. In addition, the software must enable the creation of a user database for searching, and enable the import of CIF files into the user database. In addition to the manufacturer's own scan data format, the software must also be able to import data in text format. The software should also make it possible to transfer the positively identified phases from suitable databases in the form of structure files to the software mentioned below for Rietveld refinement for direct use.

Appropriate software must be supplied for evaluation by means of Rietveld refinement, for quantifying the phase stock and for refining crystal structures. This must also be usable by at least 10 users at the same time. The software must offer functions for determining X-ray amorphous components using internal and external standards. The software must also have functions in order to calibrate peak lists in summary as a phase or to be able to use phases for quantification on the basis of the symmetry framework alone (PONKCS approach).

To evaluate the SAXS experiments, appropriate software must be supplied that allows particle size distributions and the specific surface area to be calculated. Ready-made analysis methods (Guinier or Porod) as well as adaptation methods and simulation methods must already be available.

For device cooling or connection to in-house cooling, a device with a water-cooled evaporator (water-water cooler) must be provided.

A temperature-controlled sample table is to be delivered and installed for measurements of hydration processes. The entire unit consists of a controller unit for measuring and controlling the temperature of the sample and a sample table, which must be temperature-controllable with a Peltier element. It must be possible to drive temperature profiles. The control system must be accessible with the included software. The in-situ measuring cell is advertised as a second lot. The main device manufacturer must provide the appropriate interfaces and adapters.