PKFIT - A TOOL TO FIT THE DATA FROM NEUTRON 3-AXIS SPECTROMETERS

PkFit - a user friendly software for the Macintosh, OpenVMS and UNIX w orkstations - is intended for the data processing of neutron three-axi s spectrometers. Inelastic, quasi-elastic or elastic spectra are fitte d 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 pe ak shapes through stand-alone code resources. The model can include th e Bose factor, the k(f), or k(i) correction, the neutron absorption an d the convolution of the signal with a one-dimensional or a four-dimen sional resolution function. The latter is calculated from the configur ation parameters of the spectrometer through the help of the Cooper-Na thans method or the Popovici method. Fast 4D integration is performed by means of new methods, one based on a Monte-Carlo integration techni que and the other based on a Gaussian approximation.