Welcome to TripleAxis.org
Resources for neutron triple-axis spectroscopy
Neutron triple-axis spectroscopy (TAS) is an experimental technique used to measure the structure and dynamics of atoms and magnetic moments in materials. The technique takes its name from its three rotation axes (monochromator, sample and analyzer), which select the energy of the incident neutron beam and the energy and momentum transfer of the neutrons scattered from the sample. TAS is a highly configurable and efficient way to measure inelastic neutron scattering. Common applications include phonons and magnetic excitations, the temperature dependence of magnetic diffraction (the order parameter) and structural distortions in single crystals.
Learn about triple-axis spectroscopy
About TAS
What a triple-axis spectrometer measures, why the technique is used, and a short history.
Reading list
Instrument papers, software and simulation papers, and classic science examples measured on triple-axis spectrometers.
Instruments
Instruments worldwide
14 cold and 18 thermal triple-axis spectrometers at ILL, NCNR, MLZ, ANSTO, PSI, HFIR and JRR-3, each linked to its facility page.
Compare instruments
Monochromators, flux at the sample, analyzers, polarization, filters and unique capabilities, side by side, with the working group's observations.
Tools
Software packages
24 packages for planning, resolution, data analysis, modelling (spin waves, phonons, crystal fields), simulation and instrument control.
NCNR tools
Browser tools from the NIST Center for Neutron Research: alignment dashboard, UB-matrix calculator and peak analysis.
Community
International TAS Working Group
Three focus teams (data pipeline and AI, instrumentation, outreach) with members at every reactor-based TAS facility. Contacts and how to contribute.