GEM Overview

GEM is designed to be a high intensity, high resolution neutron diffractometer for structural studies of disordered materials and crystalline powders.

GEM has an incident flight path L₁=17 metres.

The beam on GEM is rectangular with a maximum size which is 40mm high and 20mm wide, and can be changed using a set of adjustable apertures and a beam-scraper.

GEM has a nimonic chopper for removing the prompt pulse of neutrons which comes from the neutron source.

GEM has disc choppers for restricting the wavelength range and thus preventing frame overlap.

GEM has zinc sulphide scintillator detectors covering a solid angle ~3.5 steradians.

The detectors cover a very wide range in scattering angle from 1.1° to169.3°.

Last updated on 03 Sep 2004 by Alex Hannon (a.c.hannon@rl.ac.uk)