Datasets for determination of the resolution function of the Wombat High Intensity Neutron Diffraction instrument: single-crystal Ge335 monochromator

Wombat is a high-intensity neutron diffraction instrument located at the OPAL reactor, Sydney, Australia. This dataset is one of a series collected to completely characterise the resolution of the instrument in different configurations.

For this dataset, data were collected from LaB6 and  Na2Ca3Al2F14 (NAC) samples at varying takeoff angles and wavelengths, with a circular Ge335 single crystal at the monochromator position. This is the so-called "high resolution" mode of Wombat.

The files ending in .nx.hdf are raw data files closely conforming to the NeXus standard (see nexusformat.org). The files ending in .xye are three-column ASCII reduced data derived from the corresponding raw data NeXus file, with the columns being angle, intensity and standard uncertainty of that intensity. The compound (LaB6/NAC) and monochromator hkl used are included in the reduced data file name. '_nnnmtth_' refers to a takeoff angle of 'nnn' degrees.

In order to obtain the reduced data from the raw data, Monitor 1 counts were used to scale the data to 1000 monitor counts. Following this each pixel was multiplied by the corresponding value in the efficiency map contained in file eff_2023_09_DX.gumtree.hdf, after which all non-zero pixels at each angle were summed vertically and the final values output after adjusting for the variable number of pixels at each angle.