Outstations
ILL - Institute Laue Langevin,
France
ISIS, Great Britain
ILL - Institute Laue Langevin, Grenoble, France
On this page we present our new instrument at the Institute Laue-Langevin
in Grenoble, France. It started operation in Septemper 1998. We show some
drawings and pictures of the interferometer-setup. Ultra Small Angle Neutron
Scattering as well as Polarized Neutron Experiments can be performed with
this instrument. First test measurements were made and the results were
satisfying. More information can be found at http://www.ill.fr/YellowBook/S18/.
Click on the images to see the enlarged
pictures.
ISIS, Great Britan
Layout of the instrument VESTA
(the Viennese nEutron STorage Apparatus). Monochromatic cold neutrons (wavelength
= 6.27 Å) are reflected out of the white spectrum of the IRIS
beam line (1) at the pulsed neutron spallation source ISIS
by means of a pyrolytic graphite crystal (2). Arriving at the silicon crystal
mirror plate (3) the neutrons' transmission probability is changed due
to their interaction with the magnetic entrance field (4). Without it the
neutrons to be stored would not be able to pass the crystal plate but get
reflected. Being behind the first crystal plate within the cavity the neutrons
travel inside an uncoated glass guide (5) and arrive at the second crystal
mirror plate (6). With no magnetic field present they are reflected towards
the first crystal plate where the short-pulsed magnetic entrance field
has already been turned off and the neutrons are trapped inside the storage
apparatus. To release the stored neutrons from the cavity a short-pulsed
magnetic exit field (7) is switched on at the second crystal plate. The
transmission probability for the neutrons is altered again to allow them
to pass the mirror plate and get registered at the detectors (8). A high
speed shutter (9, HISS) was installed recently for efficient background
reduction. Klick on the image to enlarge the picture.
This page was created by M. Hainbuchner
Last changes: 15.12.99 by M. Hainbuchner
References and suggestions to hainbuch@ati87.ati.ac.at
