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A novel set of superconducting main precession coils has been built and installed in the Jülich-neutron spin-echo (J-NSE) spectrometer at the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching. These unique new coils comprise a field-integral optimizing field shape, fringe field compensation, and high stability. They yield an enhancement of a factor of 2.5 in the intrinsic field-integral homogeneity, i.e., the resolution. The coil concept has been developed for the ESSENSE instrument proposal for the European Spallation Source. We report on the construction of and on the first results from the new superconducting neutron spin-echo spectrometer at the MLZ in Garching where the coils are the main part of a refurbishment of the J-NSE spectrometer after twenty years of operation. [ABSTRACT FROM AUTHOR]

We use incoherent quasielastic neutron scattering to study the atomic dynamics of gold in a eutectic Au81Si19 melt. Despite the glass-forming nature of this system, the gold self-diffusivity displays an Arrhenius behavior with a low activation energy characteristic of simple liquids. At high temperatures, long-range transport of gold atoms is well described by hydrodynamic theory with a simple exponential decay of the self-correlation function. On cooling towards the melting temperature, structural relaxation crosses over to a highly stretched exponential behavior. This suggests the onset of a heterogeneous dynamics, even in the equilibrium melt, and is indicative of a very fragile liquid. [ABSTRACT FROM AUTHOR]

Following demand from the user community regarding the possibility of improving the experimental resolution, the dedicated high-intensity/extended Q-range SANS diffractometer KWS-2 of the Jülich Centre for Neutron Science at the Heinz Maier-Leibnitz Center in Garching was equipped with a double-disc chopper with a variable opening slit window and time-of-flight (TOF) data acquisition option. The chopper used in concert with a dedicated high-intensity velocity selector enables the tuning at will of the wavelength resolution Δλ/λ within a broad range, from 20% (standard) down to 2%, in a convenient and safe manner following pre-planned or spontaneous decisions during the experiment. The new working mode is described in detail, and its efficiency is demonstrated on several standard samples with known properties and on a completely new crystallizable copolymer system, which were investigated using both the conventional (static) and TOF modes. [ABSTRACT FROM AUTHOR]

Isotope production for medical and technical applications, silicon doping and testing of automotive components for higher quality - the neutron source Heinz Maier-Leibnitz (FRM II) was designed not only for scientific research, but also for industrial applications. About 30 percent of the neutrons are used by customers from industry. [ABSTRACT FROM AUTHOR]