Development of a compact six‐circle goniometer

A compact versatile six‐axis goniometer has been built which can be used with the scattering plane vertical or horizontal for anomalous X‐ray diffraction and diffraction X‐ray absorption fine structure using a tunable X‐ray undulator at SPring‐8. The diffractometer consists of a four‐circle goniometer for the standard ω, 2θ, ϕ and χ motions and a two‐circle goniometer on the 2θ arm for mounting the detector and analyser crystal. The goniometer is controlled via Ethernet, and standard data‐acquisition software with a graphical user interface has been developed. A closed‐cycle helium cryostat is mounted on the ω axis for temperature‐dependent experiments from 330 K to 14 K. Preliminary experiments on a Bi 2 Sr 2 CaCu 2 O 8 single crystal demonstrate the performance. Superstructure peaks due to the one‐dimensional spatial modulations in the b axis were recorded as a function of temperature above 20 K using an image plate.