【Hard X-ray High Energy Resolution Spectroscopy Beamline】

Hard X-ray High Energy Resolution Spectroscopy Beamline (H²O) is the first dedicated hard X-ray inelastic scattering spectroscopy beamline in China. By exploiting the features of high energy synchrotron facility HEPS, the beamline offers high energy resolution nuclear resonance scattering (NRS), X-ray Raman scattering (XRS) and resonant inelastic X-ray scattering (RIXS) techniques. These methods focus on detection of nuclear hyperfine interaction, phonon density of states and core level/valence electron excitations. These techniques can be applied in frontiers of multidisciplinary research fields, e.g. quantum science, energy science, materials science, condensed matter physics, chemistry, biochemistry, geoscience, high pressure science and environmental science, etc.

H²O beamline is located at the low-beta section ID33 of HEPS and uses in-vacuum undulator as the source. The beamline is equipped with a liquid-nitrogen-cooled double crystal high-heat-load monochromator (Si(111)/Si(311) switchable) with an energy resolving power of 10^-4~10^-5, which filters the beam to eV bandwidth. To achieve 50~100 meV energy-resolved spectroscopy, a medium energy resolution monochromator with an energy resolving power of 10^-5~10^-6 is installed. For the meV-bandpass nuclear resonant scattering, high energy resolution monochromators with an energy resolving power of 10^-7~10^-8 is adopted. The experimental station is equipped with nano-second resolution detector system, a large solid-angle multi-purpose spectrometer and various sample environments (high pressure, high&low temperature, magnetic field, electrochemical workstation, etc.).

The key parameters are listed below:

Energy range: 7~26 keV

Energy resolution:

NRS—— 1 meV @14.4 keV

XRS—— 0.7 eV @9.7 keV

RIXS—— 100 meV @8.9 keV

Focused spot size: down to 2 μm×2 μm

Photon flux at the sample:

NRS—— ~1.5×10¹⁰ phs/s/meV @14.4 keV

XRS—— ~3×10¹³ phs/s @9.7 keV

RIXS—— ~5×10¹² phs/s @8.9 keV

Director: Xu Wei (86-010-88235156, xuw@ihep.ac.cn )

High resolution spectroscopy beamline optical layout