PkFit—a tool to fit the data from neutron three-axis spectrometers

PkFit — a user friendly software for the Macintosh, Open VMS and UNIX workstations - is intended for the data processing of neutron three-axis spectrometers. Inelastic, quasi-elastic or elastic spectra are fitted by a linear background plus a series of peak functions. The program offers several built-in peak functions but the user may add its own peak shapes through stand-alone code resources. The model can include the Bose factor, the kf or ki correction, the neutron absorption and the convolution of the signal with a one-dimensional or a four-dimensional resolution function. The latter is calculated from the configuration parameters of the spectrometer through the help of the Cooper-Nathans method or the Popovici method. Fast 4D integration is performed by means of new methods, one based on a Monte-Carlo integration technique and the other based on a Gaussian approximation.