Recent advances in backscattering spectroscopy

Since its invention 50 years ago, neutron backscattering spectroscopy has seen impressive advances in count rate, whereas the dynamic range and energy resolution have remained largely the same. At present efforts are made to improve the energy resolution by an order of magnitude by replacing the Si 111 crystals by GaAs 200 and to extend the accessible energy window significantly by introducing an inverted ToF option (BATS: Backscattering And Tof-Spectroscopy) with a fast chopper system on IN16B at the ILL. First experimental results will be presented with emphasis on the BATS option.