Depth capabilities of neutron and synchrotron diffraction strain measurement instruments. II. Practical implications

In part I [Withers (2004). J. Appl. Cryst. 37, 596±606], a framework was presented for estimating the maximum feasible penetration length for neutron and synchrotron X-ray strain measurement. This calculation re ̄ected the attenuation and scattering capability of the material under examination, the incident ̄ux and detector arrangement, the likely background signal, the required strain measurement accuracy, the sampling volume, and the diffracting geometry. In the present paper (part II), preliminary calibration data acquired for a very wide range of neutron and synchrotron sources are presented. This database is used to explore the implications of the framework for delineating those conditions under which a speci®c instrument can provide useful information within a feasible timescale, in order to identify the most appropriate radiation, energy and instrumental con®guration for undertaking measurements in transmission and re ̄ection as a function of depth, and to establish guiding principles for improving the performance of existing instruments.