Spectrometer design amps up performance of neutron scattering measurements

Neutron scattering is a powerful tool that allows researchers to directly measure atomic-level dynamics and structures, with modern studies requiring increasingly powerful neutron beams to answer increasingly complex questions. However, attaining the high power outputs of a neutron source needed for state-of-the-art studies is prohibitively expensive and technically difficult. With these limitations in mind, Wang et al. focused instead on improving researchers’ ability to measure the outputs of current neutron-sources by developing a spectrometer that almost doubles performance.

The team’s spectrometer, called BOYA (or “broad and elegant” in Chinese), succeeds because of a double-column analyzer that improves the counting efficiency of traditional Rowland focusing spectrometers by nearly a factor of two. The approach optimizes crystal, sample, analyzer, and detector placement to increase measurement coverage while minimizing neutron double-scattering — a major limitation in previous approaches. Altogether, the new multiplex BOYA design is two orders of magnitude more efficient than the Nobel prize-winning triple-axis neutron spectrometer invented in 1956.

“Some multiplex neutron spectrometers use cylinder focusing in their design, which leads to a conflict in energy and momentum resolutions,” author Wei Bao said. “Rowland focusing can resolve this conflict, but the conventional method leads to waste of about half of the scattered neutron beam. The Double-Column Rowland Focusing design reported here fills the gaps to remedy the shortcoming of the traditional method.”

The new design is based on the team’s years of experience using advanced neutron spectrometers, and on the lessons they learned from invited experts who had recently built their own neutron spectrometers.

The authors plan to further decrease the noise in BOYA’s measurements by implementing appropriate shieldings.

Source: “Design and construction of the multiplexing cold neutron spectrometer BOYA with double-column Rowland focusing analyzers,” by Jinchen Wang, Daye Xu, Juanjuan Liu, Wei Luo, Peng Cheng, Hongxia Zhang, and Wei Bao, Review of Scientific Instruments (2025). The article can be accessed at https://doi.org/10.1063/5.0256044 .