Use of 2π-PSD systems for quasielastic neutron time-of-flight experiments^§

Abstract

Very-large-area detector systems for low-energy-transfer time-of-flight spectrometers are discussed. Four different kinds of linear position-sensitive detector arrays with spherical- or cylindrical-zone geometries are considered. A non-uniform sample–detector distance is involved, varying by up to 40% for cylindrical symmetry using 5 m long linear position-sensitive detectors (PSDs). Integration over large solid-angle regions causes practical consequences for data treatment, but no serious problems for spectrometer performance. We demonstrate that energy-resolution function, PWR optimization, and duration of spectral periods are essentially not deteriorated. Consequences for the normalization of measured neutron scattering data and mechanical detector implementation are discussed.

Keywords:

• Quasielastic TOF instruments
• Large PSD systems
• Energy resolution
• Optimization

Acknowledgements

I thank the Hahn-Meitner-Institut for its hospitality, and I am grateful to Prof. Franz Fujara, Inst. f. Festkoerperphysik, Technical University Darmstadt, for his continuous support concerning the planning and realization of this work.

Notes

^§This paper was presented at the WINS Conference Proceedings in Cairns, Australia, December 2005.