7C2, the new neutron diffractometer for liquids and disordered materials at LLB

6th European Conference on Neutron Scattering

Cuello, G.J.^1 ; Darpentigny, J.^2 ; Hennet, L.^2,3 ; Cormier, L.^4 ; Dupont, J.^2 ; Homatter, B.^2 ; Beuneu, B.^2

Institut Laue Langevin, av des Martyrs 71, Grenoble

38042, France^1

Laboratoire Léon Brillouin, CEA-CNRS, CEA Saclay, Gif sur Yvette Cedex

91191, France^2

CEMHTI, University of Orléans, Orléans Cedex 02

45071, France^3

Institut de Minéralogie de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 7590, Museum National d'Histoire Naturelle, IRD UMR 206, 4 place Jussieu, Paris

75005, France^4

关键词: Comparative advantage;    Cylindrical surface;    Diffraction measurements;    Diffractograms;    Disordered materials;    Multi-detectors;    Neutron diffractometer;    Sample position;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/746/1/012020/pdf
DOI  :  10.1088/1742-6596/746/1/012020

来源: IOP

【 摘 要 】

The disordered-materials diffractometer 7C2 at the Laboratoire Leon Brillouin (LLB), Saclay, France has been upgraded through the replacement of its detector. The old one, a banana like BF3detector, has been replaced by a new ensemble of3He tubes arranged on a cylindrical surface concentric with the sample position, covering an angular range of 133°, with an angular step of 0.52°. At the shortest wavelength, 0.57 Å, this represents a maximum momentum transfer of 20 Å-1. The gas pressure in the3He tubes is 30 bars, which increases the efficiency to 80% for 0.72 Å neutrons, compared to 17% for the previous detector. A larger solid angle of detection and an improved efficiency have increased the total counting rate by a factor of 22, thereby reducing random error in the diffraction measurements. The banana-like multidetector gives to 7C2 the possibility of registering a complete diffractogram over the whole angular range in one shot, which is a comparative advantage with respect to other hot-neutrons two-axis diffractometers.