A low‐temperature x‐ray goniometer for use between liquid nitrogen temperature and approximately −100°C has been designed for use with a Weissenberg camera, General Electric powder camera, or a Geiger counter system. The crystal is mounted on a goniometer head inside a vertical cylindrical stainless‐steel Dewar, and is irradiated through a polystyrene tip at the lower end of the Dewar. The crystal is cooled by conduction through the goniometer head, which is silver‐soldered to the base of a liquid nitrogen chamber inside and concentric with the outer wall of the Dewar. The Dewar vacuum is maintained by an oil diffusion pump and a forepump, through a rotating seal and the post which supports the goniometer.
The Weissenberg camera mounts on a carriage and is driven by a 60‐rpm reversing motor which also rotates the Dewar and crystal.
The carriage driving screws may be uncoupled from the motor shaft, and a Geiger counter spectrometer may be mounted on the carriage in place of the camera. The carriage is also adaptable for holding a G.E. powder camera.
A General Electric CA‐7 x‐ray tube mounted horizontally supplies the x‐ray beam.