T. Weber, Nov 2020: updated for McStas 3 / OpenACC
Description
An inelastic sample with completely uniform scattering in both Q and
energy. This sample is used together with the Res_monitor component and
(optionally) the mcresplot front-end to compute the resolution function of
triple-axis or inverse-geometry time-of-flight instruments.
The shape of the sample is either a hollow cylinder or a rectangular box. The
hollow cylinder shape is specified with an inner and outer radius.
The box is specified with dimensions xwidth, yheight, zdepth.
The scattered neutrons will have directions towards a given disk and
energies betweed E0-dE and E0+dE.
This target area may also be rectangular if specified focus_xw and focus_yh
or focus_aw and focus_ah, respectively in meters and degrees.
The target itself is either situated according to given coordinates (x,y,z), or
setting the relative target_index of the component to focus at (next is +1).
This target position will be set to its AT position. When targeting to centered
components, such as spheres or cylinders, define an Arm component where to focus at.
Example: Res_sample(thickness=0.001,radius=0.02,yheight=0.4,focus_r=0.05, E0=14.6,dE=2, target_x=0, target_y=0, target_z=1)
Input parameters
Parameters in boldface are required;
the others are optional.
Name
Unit
Description
Default
thickness
m
Thickness of hollow cylinder in (x,z) plane
0
radius
m
Outer radius of hollow cylinder
0.01
focus_r
m
Radius of sphere containing target.
0.05
E0
meV
Center of scattered energy range
14
dE
meV
half width of scattered energy range
2
target_x
0
target_y
m
position of target to focus at
0
target_z
.5
focus_xw
m
horiz. dimension of a rectangular area
0
focus_yh
m
vert. dimension of a rectangular area
0
focus_aw
deg
horiz. angular dimension of a rectangular area
0
focus_ah
deg
vert. angular dimension of a rectangular area
0
xwidth
m
horiz. dimension of sample, as a width
0
yheight
m
vert. dimension of sample, as a height
0.05
zdepth
m
depth of sample
0
target_index
1
relative index of component to focus at, e.g. next is +1