The precision of interplanar distances measured by an energy-dispersive diffractometer

According to the papers so far published about diffractometers with energy-dispersive detectors, the precision of a measured lattice spacing has been estimated to be about 0.05% at best. In the present paper, it is shown that a precision of about 0.01% is attainable without much difficulty by the use of a suitable Soller-slit system and a suitable scattering angle. This was demonstrated on an Al powder sample. It has been concluded that the limitation of precision is in the electronics rather than in the detector, when the necessary conditions are realised in the present improved system.