BEER - science case and status
Beran P.*,1,3, Šaroun J.1, Lukáš P.1, Fenske J.2, Nowak G.2, Siemers D.J.2, Kiehn R.2, Burmester J.2, Müller M.2, Woracek R.3
1Nuclear Physics Institute CAS, Hlavni 130, 25068 Rez, Czech Republic
2Helmholtz-Zentrum Hereon, Max-Planck-Straße, 21502 Geesthacht, Germany
3European Spallation Source ERIC, P.O. Box 176, 22100 Lund, Sweden
*premysl.beran@ess.eu
The time-of-flight engineering diffractometer BEER [1] (Beamline for European Materials Engineering Research), which is under construction at the European Spallation Source (ESS), will offer new opportunities for investigations of microstructures, residual stress evolutions and in-situ phase transformations under near-processing conditions. The layout of the instrument is depicted in Figure 1 and the basic parameters are listed in Table 1.
The construction of the instrument is divided into two stages called Day-1 (coloured parts in Figure 1) and Full-scope (white parts in Figure 1). The Day-1 instrument will provide reduced capabilities mainly in the detector coverage, SANS option and variability of chopper cascade but will be fully operational and comparable with the current engineering instruments worldwide.
Figure 1 – The BEER instrument schematic layout
BEER combines the high brilliance of the ESS source with large instrument flexibility. The diffractometer includes a novel beam-shaping technique, the so-called modulation technique (see Figure 2) [2]. By a time-encoded extraction of several short pulses from the long ESS pulse, a substantial intensity gain of up to an order of magnitude compared to a pulse shaping method (one pulse extraction) for high-crystal-symmetry materials can be achieved without compromising the resolution. More complex crystal symmetries or multi-phase materials can be investigated by the standard pulse shaping method. The variable chopper set-ups and advanced extracting techniques [3] offer broad intensity/resolution ranges that can be adjusted for the experiment's needs. This flexibility opens up new possibilities for in-situ experiments studying materials processing and performance under operating conditions.
Advanced sample environments dedicated to thermo-mechanical processing are foreseen to fulfil this task, e.g. a quenching and deformation dilatometer, and various deformation rigs.
Table 1 - Basic facts about the BEER instrument
|
Instrument Class |
Engineering Diffraction |
|
Moderator |
Bispectral |
|
Primary Flightpath |
158 m |
|
Secondary Flightpath |
2 m |
|
Wavelength Range |
0.8 – 6 Å |
|
Bandwidth |
1.7 Å |
|
d-spacing Range |
0.6 – 7 Å |
|
Pulse-Shaping Mode |
|
|
Resolution Δd/d |
0.15 – 0.6 % |
|
Flux at Sample at 2MW |
0.18 – 1.4∙108 n s-1 cm-2 |
|
Modulation Mode |
|
|
Resolution Δd/d |
0.1 – 0.3 % |
|
Flux at Sample at 2MW |
0.18 – 0.87∙108 n s-1 cm-2 |
