Diffractometer for synchrotron radiation structural studies of high temperature melts

A diffractometer has been constructed for structural studies of high-temperature melt with synchrotron radiation. It was designed to measure diffracted intensities from the free surface of a molten sample by scanning a scintillation counter with a fixed glancing angle of the incident beam. In order to heat samples up to 1500 °C, a small electric furnace is attached to the diffractometer. It carries a hemicircular (100 mm in diameter) cover, which has a window for the passage of x rays. The window is covered with a Kapton film. The sample container made of 30 Rh-Pt is mounted at the center of the furnace. A test measurement was performed on GeO₂. Monochromatic beams with λ = 1.32 A and its second harmonics were taken out of synchrotron radiation by a β-alumina crystal (d₀₀₂ = 11.3 A) and used as incident beams. To partial scattering curves obtained with λ and λ/2 were combined to a single curve after correction for absorption. The radial distribution function obtained from these data is in good agreement with that previously reported which was derived from diffraction data collected on a conventional diffractometer.