Aerodynamic levitation for neutron scattering experiments on liquid droplets at high temperature

Kurzfassung

We present the design and the performance of a compact aerodynamic levitation apparatus optimized for in-situ neutron scattering investigations of high-temperature liquids. This system addresses the critical challenge of low scattering volumes in containerless processing by enabling the stable levitation of large metallic and oxide droplets up to 4 mm in diameter. The device features a dual-sided CO2 laser heating configuration that minimizes axial thermal gradients, ensuring a homogeneous temperature throughout the sample. To achieve an exceptional signal-to-background ratio, the device employs a sophisticated neutron shielding concept for masking and a novel chamber geometry that effectively suppresses undesired Bragg scattering. Furthermore, a modular system of variable nozzle geometries and materials provides the device's adaptability to diverse sample classes ranging from metallic glass-formers to oxides applicable to a variety of scattering techniques. The capabilities of the apparatus are validated through neutron diffraction and time-of-flight spectroscopy experiments at the Institut Laue-Langevin. We report first results on the static structure factors of Pd-Ni-S melts, the atomic dynamics of supercooled Pd-Cu-Ni-P glass-formers, and the time-resolved crystallization behaviour of lunar regolith simulants.