|
|
| |
| |
|
| |
|
Neutron optics is
widely used in the field of neutron instrumentation. Lately the single crystals
such as Si or PG for the monochromatic and polarizing neutron beam have been
replaced with the heart of neutron optics, ¡®neutron mirror¡¯, because of it¡¯s total reflection, the
beam flux is higher than in case of using the single crystals.
Through using the total reflective effect it is
also possible to manufacture the ¡®Neutron Guide¡¯. The total reflection is due
to the index of refraction of neutron, which is smaller than 1 for the most
elements. The Ni-Monolayer is widely used as Neutron Guide.
|
|
The diffraction happens also by the reaction with periodic multi-layers(bragg'
peaks). This points out that
for the monochromator the layer
structure can be used, and the
critical angle is expanded up
to 2-4 times through gradually
changing the layer thickness(super-mirror,
F.Mezei).
|
Polarizing neutron super-mirror
|
|
|
| |
Following the invention of
neutron supermirrors by F. Mezei, the polarizing
super-mirror with Fe89Co11-Si
multilayers [2] has been built.
Here
the mixture of the Fe-Co alloy is chosen
such that its scattering length density
for the spin down component matches to the
one of silicon.
Above the critical angle
of silicon such a super-mirror reflects
only the spin up component while the spin
down component is transmitted.
|
|
|
|
Applications:
|
|
|
|
