Public procurement notice: Voluntary Ex Ante Transparency Notice
Published: 2021-06-01
Buyer: Aarhus Universitet
Country: DK
Contract type: Supplies
Procedure: Negotiated without a prior call for competition
CPV classification: 33000000 | 38000000
Estimated value: 354847 EUR
Award criteria: Lowest price

Technical requirements: Aarhus University intends to buy a Rigaku Single Crystal X-Ray Diffractometer (SCXRD) for advanced research purposes. The SCXRD instrument will be employed to measure extremely accurate single crystal X-ray diffraction data, up to the highest attainable resolutions. It is of particular importance to be able to measure at the same time both the weakest and the strongest X-ray scattering intensities accurately and to have an extremely low background intensity.
The Department of Chemistry at Aarhus University is an internationally recognized leader in extremely accurate high-resolution single crystal diffraction data collection and analysis. Our research on SCXRD is two-fold: We utilize the technique to study novel materials and we are active in research on data processing. On the materials side, one particularly important research focus has been the experimental studies of the solid-state electron density distributions in order to investigate the chemical bonding in materials. More recently, it has involved the studies of diffuse scattering to investigate the local order of materials. On the technical side we are active in developing novel strategies for raw data handling, data reduction, and new data refinement strategies. This research has been the center of several projects at the Department of Chemistry, and has involved substantial activities at advanced synchrotron facilities. However, in order to also participate in further developing these techniques to carry out extremely accurate experiments using lab-based experiments, we require access to new state-of-the-art instrumentation. The research samples to be investigated are single crystals. Many of the materials to be studied are heavy element containing inorganic crystals that are very strongly X-ray absorbing. For these materials, the most reliable data can be collected with the short wavelength X-ray sources, either Mo Kα or Ag Kα, depending on the specific crystal. To further minimize the systematic errors in the data caused by crystal absorption effects, deliberately the smallest crystals of the material of interest are chosen. In other cases, e.g. organic or organometallic materials, the X-ray scattering is much weaker; however, only the very tiniest of crystals are available. For all material types it is thus required to collect the best quality data from weakly scattering crystals, and therefore ultra-high brightness X-ray sources are needed with both Mo Kα and Ag Kα X-ray wavelengths.
Even with a bright and tunable X-ray source, the scattered intensity will be very low, e.g. for organic crystals or diffuse scattering, or contain a mixture of high and low intensity scattered signals, e.g. for inorganic crystals and diffuse scattering experiments. To obtain data of sufficient quality in both cases, we require a detector capable of providing essentially background and distortion-free images and measure both low and high intensity signals with low statistical uncertainty in a single frame. To reduce errors from frame scaling and avoid parallax type distortions in the reflection profiles towards the edge of the detector, we further require a curved detector covering a large range of diffraction angles. For benchmarking and comparing data processing strategies, it is also of vital importance that the uncertainty in the measured signal is well-described by standard counting statistics. Consequently, it is also of vital importance that the subtracted background intensity is a tiny fraction of the total measured intensity, even for the smallest signals. This combination of requirements is only achieved by a direct photon counting detector that utilizes a semiconductor pixelated sensor to directly detect X-ray photons. This must be essentially free of dark-current/background or read-out noise as well as streaking, blooming or afterglow effects in the images. It must also be capable of simultaneous readout of all pixels to prevent rolling shutter geometrical distortion in the images. X-ray photon energy discrimination must be employed to exclude X-ray fluorescence effects in the image. This combination of requirements ensures a low background intensity, reduces carry-over of background-intensity to the next frame, and the high dynamic contrast necessary to measure a broad range of intensities in a single frame.
In conclusion, we require a bright and tunable X-ray source with both Mo and Ag radiation and a direct photon counting detector with large diffraction angle coverage and a curved profile. This is only provided by the Rigaku XtaLAB Synergy-S diffractometer with a PhotonJet-S Mo and Ag source and HyPix-Arc 100
Following the notification, a standstill period of 10 calendar days will be held in accordance to paragraph 3 of Act No 593 of 2 June 2016 on the Danish Act on the Complaints Board for public Procurement. This implies that the Contracting Authority cannot sign the Contract with the winning Tenderer before the standstill period has expired.
In case of complaints about tenders or decisions, e.g. award of contracts covered by Section II or III in the Danish Public Procurement Act must be submitted to the Complaints Board for Public Procurement (Klagenævnet for Udbud) within 45 calendar days from the day after the contractor published a notice in the Official Journal on the conclusion of a contract. At the latest concurrently with submission of an appeal to the Complaints Board for Public Procurement, the complainant must inform the Contracting Authority of the alleged infringement, and whether the appeal is to be referred to the board.


Winner: Rigaku Europe SE
Award value: 354847