Observation of total external reflection of x rays from a liquid-solid interface

A new experimental scheme for the measurement of the x-ray reflectivity R from a liquid-solid interface in the range of angles of total external reflection is proposed. An x-ray beam is transmitted through a plane channel filled with a liquid under investigation. The channel is formed by two optically polished plates, one of which being the substrate under study. To eliminate the edge effects caused by surface tension, polymer films with a lyophilic coating are used as windows of the channel. For wate-silicon and glycerol-silicon interfaces, the angular dependences of R and the parameters of the interfaces are measured with the scheme developed using the CuK _α (8.05 keV) and CuK _β (8.91 keV) lines.