Monte-Carlo simulation of a single monochromator neutron Brillouin spectrometer

We have simulated the possible performance of a single monochromator neutron Brillouin scattering (NBS) spectrometer using Monte-Carlo ray-tracing methods. The NBS spectrometer is based on time-of-flight (tof) techniques and resembles quite realistically the thermal neutron NBS spectrometer BRISP planned to be installed at the HFR of the ILL in Grenoble. Using new collimator types, a monochromator with anisotropic mosaic crystals and a large position-sensitive detector, a considerable gain in the expected count rate in comparison to earlier calculations could be obtained while keeping the resolution in momentum and energy transfer within the desired limits.