D4 - Disordered Materials Diffractometer
D4, a two-axis diffractometer, uses short-wavelength neutrons from the hot source to measure diffraction patterns over a large Q-range. Combining very high counting-rate stability with very low background counts, D4 can determine the local atomic structure of disordered materials (liquids, amorphous solids, nano-structured materials, disordered crystals) with excellent accuracy.
A large array of microstrip detectors provides not only a high counting rate but also a very good counting-rate stability. Combined with a very low+stable background counting rate, D4c (the present version of the D4 instrument) is thus well-adapted for high-accuracy measurements on small samples, and for sensitive difference measurements as in the case of small scattering-length contrast.
D4 shares the beam tube H8 with the IN1 triple-axis and Lagrange (Be-filter) spectrometers, and is therefore available for only about 50 % of the time.