Single mirror plate (used to build guides in compound components).
The component Mirror models a single rectangular neutron mirror plate.
It can be used as a sample component or to e.g. assemble a complete neutron
guide by putting multiple mirror components at appropriate locations and
orientations in the instrument definition, much like a real guide is build
from individual mirrors.
Additionally, it may be centered in order to be used as a sample or
monochromator plate, else it starts from AT position.
Reflectivity is either defined by an analytical model (see Component Manual)
or from a two-columns file with q [Angs-1] as first and R [0-1] as second.
In the local coordinate system, the mirror lies in the first quadrant of the
x-y plane, with one corner at (0, 0, 0). Plane is thus perpendicular to the
incoming beam, and should usually be rotated.
Example: Mirror(xwidth=.1, yheight=.1,R0=0.99,Qc=0.021,alpha=6.1,m=2,W=0.003)
Example values: m=4 Qc=0.02 W=1/300 alpha=6.49 R0=1
Parameters in boldface are required;
the others are optional.
Name of reflectivity file. Format [q(Angs-1) R(0-1)]
width of mirror plate
height of mirror plate
Critical scattering vector
Slope of reflectivity
m-value of material. Zero means completely absorbing.
Width of supermirror cut-off
if true (1), the Mirror is centered arount AT position.
When true, non reflected neutrons are transmitted through
the mirror, instead of being absorbed.