Magnetic cooling is a reliable technique for refrigeration, however, understanding of fundamental science and materials is essential for utilizing the technique fully. Fe2P is an excellent model system for magnetic cooling materials. In this proposed experiment the diffuse scattering will be measured and the magnetic interactions on several lengthscales examined thoroughly. This will be performed by measuring the magnetic pair distribution functions at the instrument Polaris. Polaris is the most suitable instrument given the large Q-range coverage and high count rate. The results from the experiment will improve the understanding of the interactions responsible for magnetic cooling and therefore further the entire research field.