Design, Challenges and Expected Performance of an Ultrahigh Resolution Inelastic X-ray Scattering Beamline for NSLS-II
by Yong Cai (NSLS-II, Brookhaven National Laboratory, Upton, NY , USA)
at Bldg. 25b, room 109
The NSLS-II Project is currently undertaking an aggressive R&D program to develop new optics and instrumentation required to achieve an ultrahigh resolution of ~ 0.1 meV at a moderate energy of ~ 9.1 keV for inelastic x-ray scattering (IXS) experiments. The optical scheme employs a novel optical concept based on the angular dispersion effect of x-ray Bragg diffraction in asymmetric backscattering geometry. These new optics provide the possibility to achieve sub-meV energy resolution with sharp tails and high efficiency for inelastic x-ray scattering. We will present the optical design and performance studies of the beamline and spectrometer and the technical challenges we must overcome in utilizing these new optics. This new instrument is expected to greatly enhance the research capabilities beyond the current state-of-the-art IXS instruments based on conventional symmetric Bragg back reflection x-ray optics, particularly for studying the dynamics of liquids, disordered and biomolecular systems.