High-angle double-crystal X-ray diffractometry (HADOX): combination with a sealed-tube X-ray source

A new arrangement of goniometers has been introduced to a HADOX diffractometer for measuring a change in the lattice constant with a high degree of accuracy. The distance between the X-ray source and the first crystal has been shortened by a factor of five. This gives a remarkable gain in diffracted X-ray intensities without reducing the accuracy, and makes it practicable to couple HADOX with a sealed-tube type of source. Also introduced is a new program for temperature control which is suitable for varying specimen temperatures near phase transitions. The performance of the diffractometer is examined for silicon 444 diffraction with CuKα 1 .