KVASIR: A backscattering neutron spectrometer for hard condensed matter at ESS

We present the instrument concept for KVASIR, a backscattering indirect time-of-flight neutron spectrometer for the European Spallation Source (ESS). KVASIR will probe low lying excitations of single crystal hard condensed matter that many advanced technologies rely upon. The instrument is simultaneously optimized for high resolution of energy-and momentum transfer, while ensuring perturbation by high magnetic fields. Detailed ray tracing simulations, considering the true geometry and aberrations of the analyser configuration have been performed. The proposed concept has room for polarisation analysis and extreme sample environments. Inelastic neutron scattering studies of single crystal hard condensed matter, with a particular focus on quantum, at yet unseen spatial and dynamic precision under extreme conditions are hereby enabled.