LAUSR

Abstract Data analysis of Quasi-elastic Neutron Scattering (QENS) experiments often requires multiple steps involving fitting the elastic and quasi-elastic parts of spectra with several empirical functions and analytical models. Parameters of those models can be interdependent and also dependent on the momentum transfer vector Q. Here we present a modern data analysis interface dedicated for QENS data analysis implemented within the open source software Mantid. The interface has been implemented using the state-of-the-art design pattern Model-View-Presenter (MVP). The MVP, an architectural software design pattern, facilitates automated unit tests as well as decoupling of the business logic, presentation logic and the graphical interface. Several models are implemented for analysing both elastic and quasi-elastic parts of the dynamical scattering function S(Q, ω) and intermediate scattering function I(Q, t). To understand the nature of dynamics in a QENS experiments, several models are also implemented for elastic incoherent structure factor (EISF) and jump diffusions. The interface has been validated by analysing a sample of liquid water at room temperature. The nature of hydrogen bond dynamics of the hydrogen bonded organic ferroelectric 2, 4, 5 − Br3 imidazole, for the first time has been analysed using this newly implemented software. It is found that protons exhibit localised random motion in this material.