Future Trends in High Intensity Neutron Powder Diffraction

摘要

High-intensity neutron powder diffraction offers opportunities in time- and parameter-resolved diffraction, in investigation of small samples, or the precise intensity measurement to determine structure factors of disordered samples or weak peak intensities by differential diffraction. One-shot experiments show the structural evolution of solids in situ during a chemical reaction. Faster, cyclic phenomena can be observed with a stroboscopic data acquisition mode. At ILL, D20 provides the highest flux in constant-wavelength neutron powder diffraction, a stationary, curved linear position sensitive detector (PSD) and a large choice in Q-space, resolution, wavelength and flux. A new diffractometer for rapid acquisition could provide an enormous gain in detected intensity by covering a larger solid angle with a two-dimensional PSD. GEM at ISIS sets the standards in time-of-flight (TOF) instrumentation. At a future European Spaliation Source (ESS) a single-pulse diffractometer could allow for acquisitions down to the length of one pulse (20 ms) and below.