An inverse geometry neutron scattering spectrometer with graphite Venetian blind crystal analyser and a para-hydrogen filter

The design of a neutron spectrometer for inelastic scattering with inverse geometry configuration is presented. The main new characteristics of the proposed design are the use of a Venetian blind arrangement for the crystal analysers and the insertion of a para-hydrogen filter for the suppression of higher-order reflections. Based on this design, a prototype arm was built and tested at ISIS Spallation Neutron Source (UK). The results of the test measurements, showing the performances of the system, are presented and discussed.