MQfit, a new program for analyzing quasi-electric neutron scattering data

The analysis of Quasi-elastic Neutron Scattering (QENS) data of complex systems such as biological or soft matter samples in a comprehensive and explicit way often requires great efforts. Most popular software only allows to fit spectra originating from one single instrument and does not permit to extract parameters from a model that is fitted simultaneously to data taken at different instrumental resolutions. We present here a new program, mQfit (multiple QENS dataset fitting), that enables to fit QENS data taken at different spectrometers (with typical resolutions between 0.01 and 0.1 meV) and momentum transfer ranges. This allows drastically reducing the number of fitting parameters. The routine is implemented with a user friendly Graphical User's Interface (GUI), and freely available. As an example, we will present results obtained on E. coli bacterial pellets, and compare them to values published in the literature. The comparison results show that using data sets originating from different spectrometers to analyze the same sample presents great advantages, especially in such samples with complex dynamics spanning timescales of several orders of magnitude