Collecting and Processing Neutron Fibre Diffraction Data from a Single-Crystal Diffractometer

Abstract

The geometries for scanning reciprocal space for a fibre on a neutron single-crystal diffractometer are considered. Geometrical relationships are derived for the particular case of D19 at the Institut Laue-Langevin that can be readily generalized for other instruments and for the same instrument with a different detection system. An optimum data-collection strategy is proposed. Methods for processing neutron fibre data collected using this strategy are described and illustrated by studies on cellulose.

Water in Crystalline Fibers of Dihydrate β-Chitin Results in Unexpected Absence of Intramolecular Hydrogen Bonding

“…The D19 detector has cylindrical geometry, and outputs a data array of size 256(vertically) x 640(horizontally), giving an angular resolution of 0.19° in the equatorial direction. Generic strategies for collecting fiber diffraction data on D19 have been described previously [45] , [46] , and the instrument has been used for the study of a wide range of synthetic and biological polymer systems [47] – [54] . A data set was collected at ambient conditions, using a neutron beam of wavelength 1.4558 Å, using several different sample goniometer settings, and over a measuring time of about 24 hours.…”

Neutron crystallographic and molecular dynamics studies of the structure of ammonia-cellulose I: rearrangement of hydrogen bonding during the treatment of cellulose with ammonia

“…Both samples consisted of a number of capillaries that had been assembled and then glued together to form a 2 cm 9 1 cm 9 2 mm array in order to best exploit the relatively weak flux of the neutron beam. Data collection for each sample involved 25 different (crystal) goniometer settings to completely cover cylindrical reciprocal space out to a resolution of *1 Å , and took around 12 h. Generic strategies for collecting fiber diffraction data from cellulose fibers on D19 have been previously described (Langan et al 1996). The recorded detector images were corrected for variations in detector response, sample volume, and attenuation effects, and then remapped and merged into cylindrical reciprocal space, as previously described (Nishiyama et al 2008).…”

“…We have been studying molecular aspects of the conversion of cellulose between the various crystal forms associated with ammonia treatment, using a variety of techniques including crystallography, 13 C CP/MAS NMR, FT-IR, differential scanning calorimetry, and theoretical modeling (Langan et al 1996(Langan et al , 1999Langan 2005;Nishiyama et al 2002Nishiyama et al , 2003Nishiyama et al , 2008Nishiyama et al , 2010aWada 2001;Wada et al 2001Wada et al , 2004Wada et al , 2006Wada et al , 2009a. Large cellulose fibers from seaweeds have been adopted as a model system, because they are highly crystalline and therefore provide high-resolution crystallographic and spectroscopic data.…”

Synchrotron X-ray structures of cellulose Iβ and regenerated cellulose II at ambient temperature and 100 K

“…C++ software was written to automatically recognize pixels associated with those regions and to produce a file in which the affected pixels are flagged by a negative value. Further C++ software was written to encapsulate the fiber diffraction geometries formulated by Fraser et al (1976) and Langan et al (1996) so that the diffraction images could be folded into cylindrical reciprocal space whilst excluding flagged pixels, Figure 3.…”