A resonance detector spectrometer at KENS

We have tested a resonance detector spectrometer at the KENS neutron source, using 181Ta, 121Sb and 149Sm resonances and bismuth germanate (BGO) scintillators. In the process we encountered and solved numerous background problems, and discovered a time-focussing principle. We measured the scattering from a number of materials and have so far analyzed results for bismuth, vanadium and graphite, which we present. Tests of cooled absorbers indicate that resolution of 70 meV is possible with 181Ta.