biostudies-literatureZhou KJNational Natural Science Foundation of China (National Science Foundation of China)76https://www.ebi.ac.uk/biostudies/studies/S-EPMC12820124biostudies-literatureUnknown15(1)Resonant inelastic X-ray scattering (RIXS) is a photon-in/photon-out spectroscopic technique which has become increasingly important for the condensed matter physics community. The development of the RIXS instrumentation in soft X-ray and hard X-ray range facilitated the research in 3d and 5d transition metal (TM)-based materials, respectively. However, the tender X-ray (2000-3000 eV) RIXS covering most of 4d TM-based materials severely falls behind due to the lack of high-performance energy dispersive optics. Here, we demonstrate the design and fabrication of a laterally graded multilayer grating (MLG) optics for the establishment of the tender RIXS at the I21 RIXS beamline in Diamond Light Source. The successful implementation of the MLG boosts the photon flux by more than an order of maLight, science & applicationsTRIXS: a multilayer grating solution towards highly efficient resonant inelastic tender X-ray scattering.PMC1282012412075170Kozhevnikov IVWen SChoi JWang HHuang QGarcia-Fernandez MQi RRice TZhuang YTippireddy SZhou KJAgrestini SZhang ZWang ZWalters AfalseTRIXS: a multilayer grating solution towards highly efficient resonant inelastic tender X-ray scattering.Resonant inelastic X-ray scattering (RIXS) is a photon-in/photon-out spectroscopic technique which has become increasingly important for the condensed matter physics community. The development of the RIXS instrumentation in soft X-ray and hard X-ray range facilitated the research in 3d and 5d transition metal (TM)-based materials, respectively. However, the tender X-ray (2000-3000 eV) RIXS covering most of 4d TM-based materials severely falls behind due to the lack of high-performance energy dispersive optics. Here, we demonstrate the design and fabrication of a laterally graded multilayer grating (MLG) optics for the establishment of the tender RIXS at the I21 RIXS beamline in Diamond Light Source. The successful implementation of the MLG boosts the photon flux by more than an order of ma2026-01-01T00:00:00Z2026 Jan2026-06-06T18:01:03.501Z2026-06-04T03:09:50.63ZS-EPMC128201244155903810.1038/s41377-025-02172-7