A detailed description of a two-axis goniometer paired with an x-ray source is provided, encompassing measurements of double-crystal integrated reflectivity for diffractors employed in JET spectrometers. Polarization adjustments to these measurements are computed to estimate single-crystal integrated reflectivity. Synchronized parallel and dispersive diffractor motion profiles at this facility exhibit favorable angular error distributions, engaging all motors with deviations of ∼2 arcsec across the full range of accessible Bragg angles (0°–86°).
A. M. Patel (2026) studied this question.