The diffraction of X-rays by distorted-crystal aggregates. IV. Diffraction by a crystal with an axial screw dislocation

In the reciprocal-lattice representation, the regions of high intensity become discs perpendicular to the dislocation axis.The variation of amplitude of reflexion across a disc can be represented either as an integral or as a finite series involving Bessel functions.Expressions for the integral breadths of lines on powder photographs are obtained in closed form.