Analysis of the axial misalignment error in precision lattice parameter measurement by the Bond technique

This paper presents an analysis of the errors in lattice parameter measurements by the Bond method due to axial misalignment of the collimator and the crystal normal. These errors were considered separately in the original presentation by Bond, but primarily with the intent of reducing the errors to acceptable limits by defining the limits of misalignment. In cases where misalignment cannot be prevented, it becomes necessary to determine the error quantitatively so that corrections can be made. The analysis leads to the result that the error in lattice parameter is related to the difference, rather than the sum, of the misalignment errors considered by Bond, and a useful method of determining the error is described. The analysis is supported by measurements of the lattice parameter of copper.