A Device for Carrying Out High-Precision Measurements of Small-Angle X-Ray Scattering on Liquid Samples
摘要
A liquid sample holder for small-angle X-ray scattering measurements has been developed and tested that allows for a significant increase in the signal-to-noise ratio with a small amount of sample material. The proposed device consists of a vertically positioned capillary made of a chemically resistant material with a diameter of 0.005–5.0 mm, the lower edge of which is rigidly fixed above the center of the incident X‑ray beam at a distance equal to the radius of the drop. A drop of liquid sample is squeezed out through the lower end of the capillary. Surface tension forces ensure the spherical shape of the droplet and hold it at the end of the capillary. The scattering of a beam passing through a drop is axisymmetric since the spherical shape of the sample drop best meets this requirement. The presence of a sample in such a device eliminates the presence of additional elements in the radiation beam that could introduce distortions into the signal, which allows for high-precision measurements using the small-angle X-ray scattering method. Test measurements were carried out that showed a significantly more isotropic scattering pattern, and the optimal relative positions of the radiation beam and the sample drop were determined. The simplicity of the proposed holder design and its versatility for measuring various samples are undeniable advantages.