Small-angle scattering (SAS) addresses density fluctuations in nano- and microstructures. The full morphology and structure of the material under investigation can be extracted, e.g. shape, geometry and arrangement of nanoparticles. In SAS, the use of two-dimensional detectors is mandatory. As key scientific examples, namely:

  • Kinetics in the millisecond to microsecond time regime in two dimensions. This involves initial stages of nucleation in modern nano-composite and hybrid materials as well as non-equilibrium solution kinetics
  • Magnetisation dynamics
  • (Magnetic) nanostructures, e.g. magnetic domain switching
  • Structural biology, which goes even to nanosecond time-scales
  • Time-resolved scattering experiments (selection of right parameters)

From the methodological point of view, scanning experiments using micro- and nano-focus X-ray beams as provided by MiNaXS are one prominent example. The aim is to reconstruct images in terms of visualization ("maps") in quasi-real-time. This enables us to prepare a “smart experiment” with the possibility for experiment strategy optimization. This needs feedback to the instrument itself. The data rates are estimated on the basis of today’s (!) commercially available detectors, such as the PILATUS (Dectris). It must be noted that often complementary information is gained in-situ by using additional wide-angle scattering detectors: 200Hz x 2 Detectors, PILATUS 300k => 400MB/s. However, within the PoF2-period, we estimate a factor of 30 increase in data rate due to the advent of second generation PILATUS type detector ("XFS") with a read-out time in the 100#s range (compared to 2.7ms today) and an increase in active pixel area from 300k to 1M. These detectors run at 1 kHz dead-time free. This leads to 4GB/s. This requires the following operational constraints:

  • ROI might be used
  • Online assessment and control
  • Lossless compression A note on lossless compression: Especially in grazing incidence SAS (GISAS) depending on the experiment the full detector image is needed. For high-speed applications, in special cases, part of the GISAS pattern might be extracted from the full image and thus the data volumes reduced.

The analysis demands can be summarized as follows:

  • Joint refinements for multi-probe experiments (SR and N)
  • Real time analysis for lower data rates (in terms of radiation damage, low scattering power, flux, choppers, …)

Taking into account the pulsed sources like SNS, ESS, and XFEL, plus the novel instrumentation being implemented, a tremendous increased count rate on the detectors ("one image per shot") is expected. Especially for neutrons, this will lead to a count rate increase of up to a factor of 100 compared to today’s highest flux reactor, the ILL. However, this time scale is expected to extend into PoF III, showing that HDRI must be a long-term strategy. These new sources enable pump-probe experiments with 1M of data every millisecond.