[ Identification | Description | Input parameters | Links ]

The ILL_H22_D1B Instrument

Identification

• Site: ILL
• Author: FARHI Emmanuel (farhi@ill.fr) and SANCHEZ Javier (sanchez-montero@ill.fr)
• Origin: ILL
• Date: June, 2008

Description

The D1B diffractometer on the H22 curved thermal guide at the ILL.

D1B is a two-axis spectrometer dedicated to diffraction experiments requesting a
high neutron flux. A great number of experiments performed on D1B concern the
determination of magnetic structures. At small angles where the magnetic peaks
are expected, a high spatial resolution can be achieved, the FWHM reaches 0.2°
(for a sample with = 8 mm). Three pyrolitic graphite monochromators focusing
onto the sample position provide a flux of 6.5·106 n cm-2s-1. A second
wavelength with = 1.28 Å is available by using a germanium monochromator. D1B is
equipped with 3He/Xe position-sensitive detector composed of a system of
multi-electrodes with 400 cells, which span a 2 range of 80°. The detector can
be moved so that an angular range of 2°<2<130° can be covered. The specially
designed cryostat is known for its low background crucial for some experiments
with small intensity changes. Because of its high flux at = 2.52 Å together with
the large multi-detector, surface studies such as adsorbed phases as well as
real-time diffraction experiments are possible. Collecting a diffraction pattern
with sufficient statistics in minutes (1-5 min) even seconds allows in situ
studies of reaction kinetics. A fast detection of phase transitions can also be
obtained by scanning the temperature. A complete thermal variation of the
diffraction patterns (1.5 - 300 K) can be achieved in few hours (3-5h).

Input parameters

Links

• Source code for ILL_H22_D1B.instr.

[ Identification | Description | Input parameters | Links ]