On the use of a small two-dimensional position-sensitive detector in neutron diffraction

Abstract

A small position‐sensitive 3He gas detector has been developed for diffraction studies using short‐wavelength neutrons. It covers 32 × 32 pixels with a 2 mm resolution, which in the present set up corresponds to 0.25°, and the efficiency is 75% at a wavelength of 0.8 Å. The detector has been used for standard data collection, as well as for studies of twinned crystals and measurements involving parasitic reflections. In all cases it has improved the mode and speed of the measurement, with gain factors compared with single detectors which range from more than two in standard measurements to several hundred for the study of details of the Bragg peak(s). The computation time in data analysis and the storage of the data are no major limitations, partly due to the smallness of the data array, and partly due to efficient packing routines.

On the crystal structure and compressional behavior of talc: a mineral of interest in petrology and material science

“…D9 is equipped with a small two-dimensional area detector (Lehmann et al 1989), which for this measurement allowed optimal delineation of the peak from the background. Reflections of the type ±h, ±k, ±l to 2θ max = 61° were scanned, out of which 635 were "observed" (Table 1).…”

Magnetic structure and magnetocalorics ofGdPO4

“…For the other elements, the coherent scattering lengths reported in the literature have been taken, i.e., b P = 5.130 × 10 −12 cm, b O = 5.803 × 10 −12 cm, similarly for the Gd magnetic form factor [9]. For this experiment, D9 was equipped with a small area detector of 64 × 64 mm 2 consisting of 1024 pixels at 40 cm from the sample [10], which allowed determination of the centroids of all observed reflections and optimal delineation of each peak from the background. The crystal was a platelet normal to the (101) crystal direction, 0.5 mm thick with face dimensions 1 × 1.5 mm 2 .…”

Glycyl-L-alanine: a multi-temperature neutron study

“…Neutron diffraction measurements were conducted at the Institut Laue-Langevin (ILL), Grenoble, on the high-resolution four-circle diffractometer D9 equipped with a small-size position-sensitive 3 Hegas detector (Lehmann et al, 1989) that allows an optimal discrimination of the Bragg peak from the background. A wavelength of 0.8313 (2) Å from a Cu(220) monochromator was chosen for the parametric data collection at four temperatures, i.e.…”