A double-radius Gandolfi X-ray camera for the generation of powder-like diffractograms of small single crystals, using an imaging plate detector

This is a report on the construction and the main features of an X-ray camera following the Debye-Scherrer geometry, combined with a sample mounting and rotation device for single crystals as first suggested by Gandolfi. Doubling of the camera radius and replacing of the wet-film technology by a highly dynamic imaging plate system allows well resolved digital diffraction patterns to be recorded within a short exposure time. Sophisticated calibration, correction and evaluation possibilities are supported by suitable software. Further optional improvements, such as the evacuation of the camera, the adaptation of totally reflecting collimators for an almost parallel primary X-ray beam and a built-in instead of an external imaging plate readout device, will further improve the resolution and peak to background ratio. The simple and versatile apparatus is indispensable for the fast and non-destructive identification of unique mineralogical or technical micro-samples in the form of single-crystal pieces. Initial representative data sets attest to the accuracy, efficiency and sensitivity of the method presented.