Performance of a hard X-ray split-and-delay optical system with a wavefront division

The performance of a hard X-ray split-and-delay optical (SDO) system with a wavefront division scheme was investigated at the hard X-ray free-electron laser facility SACLA. For the wavefront division, beam splitters made of edge-polished perfect Si(220) crystals were employed. We characterized the beam properties of the SDO system, and investigated its capabilities for beam manipulation and diagnostics. First, it was confirmed that shot-to-shot non-invasive diagnostics of pulse energies for both branches in the SDO system was feasible. Second, nearly ideal and identical focal profiles for both branches were obtained with a spot size of ∼ 1.5   µ m in full width at half-maximum. Third, a spatial overlap of the two focused beams with a sub- µ m accuracy was achieved by fine tuning of the SDO system. Finally, a reliable tunability of the delay time between two pulses was confirmed. The time interval was measured with an X-ray streak camera by changing the path length of the variable-delay branch. Errors from the fitted line were evaluated to be as small as ± 0.4   ps over a time range of 60   ps.

Source: Journal of Synchrotron Radiation - December 6, 2017 Category: Physics Authors: Hirano, T. Osaka, T. Morioka, Y. Sano, Y. Inubushi, Y. Togashi, T. Inoue, I. Matsuyama, S. Tono, K. Robert, A. Hastings, J.B. Yamauchi, K. Yabashi, M. Tags: hard X-ray free-electron laser split-and-delay optics multi-crystal optics X-ray photon correlation spectroscopy research papers Source Type: research