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