Delivery, installation and commissioning of an X-ray diffractometer for X-ray diffraction studies on powders in Bragg Brentano geometry
The scope of service is the delivery and commissioning of an X-ray diffractometer in Bragg-Brentano geometry and theta/theta configuration for qualitative and quantitative phase determination in building materials and their raw materials. A high proportion of the device is intended for use in teaching, therefore a high degree of user-friendliness and the setup of user-defined measurement sequences is required, as well as economical operation, ideally largely maintenance-free. The X-ray tube must be user-replaceable, regardless of whether an aged tube is being replaced or a tube is inserted with another anodenmal material. Copper and cobalt can be used as anode material for the device advertised here. The initial equipment must be fitted with a copper tube.
The sample to be measured must be able to rotate at different speeds during measurement, between standstill and max. 1 revolution per second. The device must be equipped with an automatic sample changer, which has at least 30 positions in the standard configuration for automatic sample change for measurement. The sample changer must not impair accessibility to the gonio meter or must be able to release it easily if necessary, in order to be able to change the pro bench, for example. The sample changer should be expandable by another 30 positions for future applications.
The detector must be able to record and process the highest possible counting rate (at least 100,000 cps) in a short time. The detector must also be used as a point detector as well as a 1D and 2D detector.
In addition, the detection system must be able to hide spectral X-ray tube artifacts such as the K-line of the anode material without solid-state filters (metal foils). 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. This must apply to both Cu anode and co-anode X-ray tubes. For these two anodes, the efficiency of the detector must be > 94%.
The divergence aperture system (primary and secondary side) must be used both as a fixed aperture and programmable as a variable aperture to illuminate a constant length over the entire scan range. Axial divergence divergence divergence (Soller divergence) must be present in 2° - 2.5° divergence and 4° - 4.5° divergence and be user-replaceable. An additional lens shade must be installed and adjustable to minimize scattering intensities at small angles (e.g. measuring clay preparations). This should ideally provide an automatic adjustment of the distance to the sample as the diffraction angle increases.
It must be possible to use different preparation holders (Ø 51 mm), e.g. standard holders for front-side preparation, backloading preparation, specimen holders for wet samples (kapton foil cover), specimen holders with small surfaces (Si single crystal), sample holders for oriented clay mineral preparations. Sample carriers for backloading preparation, wet samples and clay minerals (10 pieces each) as well as specimen holders with small substrates (2 pieces) must be available in the basic configuration.
The radius of the goniometer should be variable without any necessary adjustment. The goniometer must have an accuracy of 0.01° or better, with a reproducibility of at least +/- 0.0002°. The extendable angle range must be from -100° to 165° 2 theta.
The device must be a full protection device according to StrSchV with type approval (BAZ).
The computer to control the diffractometer must have up-to-date hardware components, including at least one Intel Core i or AMD Ryzen series CPU, 8GB of memory. The operating system must be installed in German, as a 64 bit version. In addition to the manufacturer-specific assignment of external ports, at least 3 USB 3.0 ports must be free to use, and an RJ 45 port with at least 100 Mbit for connection to the in-house network.
The monitor must have a diagonal of at least 22 inches with at least FHD resolution (1920 x 1080). The keyboard must have German layout (QWERTZ). All hardware should also support the next generation operating system
Phase identification software must be supplied with sufficient licenses for simultaneous use by at least 10 users. The software must be able to use the “Crystallography Open Database” (COD) to search for phases, as well as PDF 2 (version 2003) and the PDF4/4+ database. The software must also enable the creation of a user database for search 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 Rietveld refinement software mentioned below for direct use.
Appropriate software must be supplied for evaluation using Rietveld refinement, quantification of phase inventory and refinement of crystal structures. This must also be usable by at least 10 users at the same time. The software must provide functions for determining X-ray amorphous proportions using internal and external standards. The software must still have functions in order to calibrate peak lists as a phase or to be able to also use phases for quantification based on the symmetry lust alone (PONKCS approach).