The resonance detector spectrometer for neutron spectroscopy in the eV energy region

The intense fluxes of epithermal neutrons, available at the ISIS facility, make possible Deep Inelastic Neutron Scattering (DINS) measurements in the 1-100 eV energy region. At present these are performed with the VESUVIO spectrometer, a Resonance Filter Spectrometer recently installed at ISIS. The physical quantities derived are the atom momentum distribution and the mean kinetic energy. The scattered neutrons are detected by Li-6-glass scintillation detectors, which however suffer of heavy efficiency loss at neutron energies above 30 eV. With the aim of extending the kinematic region (homega) accessible in DINS measurements, the Resonance Detector Spectrometer (RDS) configuration has been recently revised, and encouraging results have been obtained both on eVS and VESUVIO spectrometers in DINS experiments up to final neutron energies of about 70 eV