THE DEVELOPMENT OF THE PRISMA SPECTROMETER AT ISIS

Inelastic neutron scattering experiments on single crystal specimens at a pulsed neutron source require new instrumentation and measuring techniques. In this paper we describe the development and performance of the PRISMA spectrometer which has recently been installed at the ISIS spallation neutron source, Rutherford Appleton Laboratory, UK for the purpose of carrying out such measurements. This spectrometer is particularly suited to the performance of quick overview measurements of the dispersion curves in single crystals over a wide neutron energy transfer range. It is also very efficient at measuring changes in the dynamical scattering function introduced by external parameters such as temperature, pressure or magnetic field. Experimental results from the commissioning phase which demonstrate the potential of the PRISMA spectrometer are presented.