A program for processing neutron data in the tradition of Homer and Horace, eniius is a utility for embedding neutron instrument information using (nx)spe files.

Proper analysis of inelastic neutron scattering (INS) data requires taking the instrument resolution function into account [1], and this in turn requires particular information about the neutron spectrometer (instrument) recording the data. Hitherto this information has been obtained post-facto from the program(s) performing the resolution convolution.

In the interest of FAIR data and to improve usability, this information should be embedded in the raw datafiles produced by the instrument, and the aim of eniius is to provide a utility for just this purpose.

• Instrument data is embedded in a NeXus data file as a NXinstrument group.
• The embedded instrument is at a minimum enough to be imported into Horace for resolution calculation.
• eniius also has the facility to export this information as McStas instrument files for ray tracing simulations of the resolution function, and can also import certain McStas instrument files to embed in raw data files.
• Is compatible with the IBEX data acquisition program as well as the Mantid data reduction suite.
• Has a GUI for visualising the instrument data.