The final configuration of TOSCA neutron spectrometer

The forward and backward scattering parts of a new neutron spectrometer, TOSCA-II, replacing the old TFXA and TOSCA-I, have been successfully installed at the ISIS pulsed neutron source. The results show a significant enhancement in the counting rate due to the larger detector area. The improved resolution (to 1.5÷3% of the energy transfer) as compared with the previous instruments (TXFA 2.5 ÷ 3.5%, TOSCA-I 2÷3.5%) has been achieved by increasing the primary flight path from 12 m to 17 m. A chopper has been added in order to avoid neutron frame overlap and to reduce the fast neutron background. Additional diffraction capability will be installed in the near future.