Resolution of the VESUVIO spectrometer for high-energy inelastic neutron scattering experiments

New perspectives for epithermal neutron spectroscopy have been opened up as a result ofthe development ofthe Resonance Detector and its use on inverse geometry time-of-flight spectrometers at spallation sources. A special application ofthe Resonance Detector is the Very Low Angle Detector Bank (VLAD) for the VESUVIO spectrometer at ISIS, operating in the angular range 1deg<2theta<5deg. This equipment allows High-energy Inelastic Neutron Scattering (HINS) measurements to be performed in the q,w kinematical region at low wavevector( q<10 A^-1) and high energy (unlimited) transfer hw>4500 meV, a regime so far inaccessible to experimental studies on condensed matter systems. The HINS measurements complement the Deep Inelastic Neutron Scattering (DINS) measurements performed on VESUVIO in the high wavevector q (20 A^-1250 A^-1) and high energy transfer hw> 1eV, where the short-time single-particle dynamics can be sampled. This paper will revise the main components ofthe resolution for HINS measurements of VESUVIO. Instrument performances and examples of applications for neutron scattering processes at high energy and at low wavevector transfer are discussed.