Thermal relaxation in a perfect crystal leveraging pump-probe dark-field X-ray microscopy at synchrotron radiation facilities

A pump-probe dark-field X-ray microscopy (DFXM) experiment was carried out at the Advanced Photon Source (APS) with nanosecond drive laser pulses and hybrid mode x-ray probe pulses. We observe a thermal decay due to laser-induced heating, probed during the subsequent thermal diffusion in a Germanium single crystal by capturing DFXM images of a Bragg peak using X-rays from a single electron bunch at a synchrotron source. The importance of this work lies in demonstrating an ability to obtain such an image using a single bunch on a synchrotron beamline. With an anticipated improvement of delivered flux to a sample by at least two orders of magnitude after a brightness upgrade of such a synchrotron source, we expect this work to open a new pathway to study nanosecond to millisecond correlated dynamics.