The multidetector neutron spin echo spectrometer IN11B

Abstract

The first multidetector neutron spin echo spectrometer IN11B has been designed, constructed and measurements performed. The general features of the spectrometer are presented and the performance is illustrated by some measurements. It was shown that it is possible to acquire the real-time dynamic neutron scattering cross-sections simultaneously, for a wide range of momentum transfers, using a multidetector bank and an especially designed wide angle Larmor precession field magnet. This provides a method for following the temporal evolution of a scattering process remarkably rapidly with energy resolution comparable to that of the IN11 single detector spectrometer. The experimental results obtained with the IN11B spectrometer on the critical dynamics of the compound TbAl 2 in the vicinity of the Curie temperature are presented and discussed.