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A new neutron diffractometer with multiple detectors combining the advantages of time‐of‐flight and double‐axis diffractometers
Author(s) -
Turba W.,
PeterlinNeumaier T.,
Steichele E.
Publication year - 1993
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889892008252
Subject(s) - diffractometer , optics , neutron , detector , spectrometer , neutron diffraction , powder diffractometer , resolution (logic) , materials science , angular resolution (graph drawing) , diffraction , physics , nuclear physics , mathematics , computer science , scanning electron microscope , combinatorics , artificial intelligence
In this paper, the principle of a new neutron diffractometer is presented. In this diffractometer are combined the advantages of a high‐resolution time‐of‐flight (TOF) diffractometer and some essential characteristics of a classical double‐axis spectrometer (DAS), specific disadvantages of both instruments being eliminated. Its name, MARTIN (multiple‐angle high‐resolution time‐of‐flight instrument for neutrons), is derived from the particular instrumental set‐up. With the MARTIN diffractometer, a neutron pulse from a narrow wavelength band (0.2–0.5 Å) impinges on the sample. The diffracted radiation is registered and time‐analyzed by detectors located at several scattering angles. The angular arrangement of the detectors is such that each detector samples a different portion of the diffractogram, with the portions detected by adjacent detectors partially overlapping. These partial diffractograms can be conjoined to yield the complete diffractogram of interest. This new machine has all the advantages of a TOF diffractometer: no contamination of the primary beam by higher orders, higher counting rates because of the possible utilization of the entire Debye–Scherrer ring, higher flexibility because no monochromators are needed and less strict requirements of mechanical precision as a result of the fixed detector arrangement. In addition, the use of a narrow wavelength band reduces the problem of absorption and extinction corrections in TOF diffractometry to one solvable by the well known data treatment of two‐axis diffractometry. A prototype of the MARTIN diffractometer was designed for powder diffraction and installed as an extension of the TOF diffractometer at the Munich Research Reactor (FRM) in Garching, where its characteristics were tested on a powder sample of Al 2 O 3 .