RZera 3.0 unifies neutron data reduction across China’s spallation source instruments

Researchers at the China Spallation Neutron Source (CSNS) have unveiled RZera 3.0, a major upgrade of the software platform that turns raw neutron scattering data into usable scientific results. The work, led by Rong Du of the Institute of High Energy Physics, Chinese Academy of Sciences, and the Spallation Neutron Source Science Center, is described in a peer-reviewed publication and marks a shift from a single-instrument tool to a centralized platform serving a significant portion of the CSNS user community.

The scale of the challenge is considerable. In time-of-flight experiments at CSNS, which probes material structure and dynamics across physics, chemistry and materials science, a single measurement can generate billions of raw events. Before these become scientific quantities such as diffraction patterns, pair distribution functions (PDFs) or dynamic structure factors, they must pass through complex corrections, including absorption, multiple scattering, detector efficiency and background subtraction.

The core innovation in version 3.0 is a unified, modular dataflow architecture. Instead of the original “one-click” paradigm, the reduction pipeline is split into discrete modules that users can execute, inspect or bypass, with each step’s output plotted so its evolution can be monitored. This gives beamline scientists transparency and control while retaining a quick-reduction mode for routine users who simply need processed data.

Three technical advances follow from this redesign. The first concerns PDF analysis, where RZera 3.0 integrates a Hermite function fitting method that exploits the fact that Hermite functions are eigenfunctions of the Fourier transform. Data from all detector groups are fitted simultaneously, each convolved with its own resolution function. The result is a PDF effectively deconvolved from instrumental resolution and free of the artifacts introduced by manual stitching. In tests on a standard silicon sample, the method achieved refinement quality comparable to a well-optimized conventional workflow, with an Rwp of 12.54 percent versus 12.36 percent, while eliminating low-r oscillations and operator dependence.

The second advance is an automated attenuation correction algorithm for cylindrical sample cells. The algorithm accounts for the sample’s attenuation of the cell’s scattering at each detector pixel, using a geometric scattering model combined with the Beer-Lambert law. When tested on the NIST SRM 640d silicon standard, the correction produced reduced Rietveld Rw values across the low-, middle- and high-angle detector groups.

The third advance extends the platform beyond powder diffraction for the first time. RZera 3.0 now includes a complete workflow for the high-energy direct geometry inelastic spectrometer (HD), China’s first time-of-flight inelastic neutron scattering spectrometer. A comparison of the same sample measured at CSNS-HD and at ISIS showed excellent agreement, supporting the reliability of the new inelastic workflow.

RZera 3.0 is now deployed across the multi-physics, high-pressure and high-resolution powder diffractometers as well as the HD spectrometer. It provides both offline and online data reduction through a consistent interface, following a “unified architecture, specific instrument” design philosophy. The online toolset includes real-time data viewers, beam monitoring and an AI-based indexing tool that predicts crystal system, space group and lattice parameters.

The authors note that the platform has evolved from a single-instrument tool into a centralized resource with an open, modular framework designed for collaboration and future algorithm integration.

By combining modular transparency, improved PDF and background corrections, and the first inelastic-spectrometer workflow at the facility, RZera 3.0 aims to streamline the path from billions of raw detector events to publishable scientific quantities for users across the CSNS instrument suite.

Subject of Research: A unified modular software platform for neutron scattering data reduction at the China Spallation Neutron Source

Article Title: RZera 3.0: A unified and modular platform streamlines neutron scattering data reduction at China's spallation source

Article References: RZera 3.0: A unified and modular platform streamlines neutron scattering data reduction at China's spallation source. Original publication (Bibliographic details unavailable.)

Image Credits: AI Generated

DOI: Not provided

Keywords: neutron scattering, China Spallation Neutron Source, data reduction, pair distribution function, powder diffraction, inelastic neutron scattering, Rietveld refinement, background subtraction, time-of-flight, software platform, RZera, unified