Boundary Conditions in the Numerical Integration of Takagi‐Taupin Equations. Application to the Laue and Bragg Cases

Boundary conditions in the numerical integration of the Takagi‐Taupin equations are investigated in both Laue and Bragg reflections. They show how an incident spherical or plane wave may be simulated, and they discuss the accuracy of the calculation. In the Laue case the conclusion is that a spherical incident plane wave is well simulated lightening one elementary source, and a plane wave lightening more than 30 elementary sources. In the Bragg case it is shown that the accuracy of the numerical integration depends upon the distribution of sources and the thickness of the crystal. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA