Parameter Fitting in Neutron Scattering

Area: Chemistry

Neutron scattering is an important research tool destined to understand the molecular dynamics of solids and liquids. Its purpose is to figure out precise details of the positions, motions, and magnetic properties of atoms by investigating neutrons colliding with atomic nuclei and measuring their change of momentum and energy. Experimental data obtained from neutron scattering experiments is compared to a theoretical model implemented as a computer program. The adjustment of model parameters to experimental data is carried out by solving an unconstrained minimization problem. The optimization algorithm makes use of the derivatives of the objective function. The forward mode of automatic differentiation is applied to accurately and efficiently compute the corresponding derivatives.