Abstract
We develop practical expressions for the focusing conditions of fully general crystal analyzer inelastic neutron scattering instruments having two-dimensionally extended sources (moderators), samples, analyzer crystals, and detectors. We show their relationships to focusing conditions for powder diffraction and single-crystal diffraction instruments. We demonstrate that geometries other than the traditional backscattering arrangement, using more general sample, analyzer, and detector orientation angles, can provide high resolution and offer potential advantages in design. The results apply to the use of mosaic as well as perfect single-crystal analyzers.
| Original language | English |
|---|---|
| Pages (from-to) | 784-806 |
| Number of pages | 23 |
| Journal | Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |
| Volume | 483 |
| Issue number | 3 |
| DOIs | |
| State | Published - May 11 2002 |
| Externally published | Yes |
Funding
This work has been carried out in part under US Government Contract No. W-31-109-ENG-38. We are indebted to Henry A. Belch, IPNS, for generating the crystal analyzer spectrometer movie. One of us (JMC) expresses gratitude to the Rutherford-Appleton Laboratory for providing opportunities for uninterrupted thinking on this subject. We are all grateful to John R. D. Copley, Eugene Iolin, and Kenneth W. Herwig for critical readings of this manuscript and for their helpful suggestions, and to one of this paper's referees for the very useful suggestion regarding the definition of the angle ψ.
| Funders | Funder number |
|---|---|
| Government of South Australia | W-31-109-ENG-38 |
Keywords
- Backscattering spectrometers
- Crystal analyzer spectrometers
- Neutron scattering
- Pulsed neutron sources
- Quasielastic scattering
- Resolution
- Time focusing