The instruments DREAM and T-REX of the new European neutron source ESS were simulated using VITESS. The figure shows the intensity as a function of wavelength (x-axis) and horizontal divergence (y-axis) after the switch of DREAM, which merges the beams from cold and thermal moderators. The switch consists of a neutron mirror, that couples the neutrons originating from the cold moderator into the neutron guide, while neutrons from the thermal pass straight through the mirror into the neutron guide. As a result the instrumental capabilities are increased thanks to the extended spectral range.
