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McStas: Monitor_Sqw

[ Identification | Description | Input parameters | Links ]

The Monitor_Sqw Component

This component is a Sqw Monitor that records the dynamic structure factor S(q,w) from a scattering location, seen from a detector location.

Identification

Description

This component is a specialized Monitor_nD variation, which records the S(q,w)
scattering law. It accepts about the same parameters as the Monitor_nD, but makes
use of the 'q' and 'w' user variables. The neutrons are restored in their previous
state after neing detected (restore_neutron=1).

The monitor records the intensity as a function of q=kf-ki and w=Ef-Ei were the
'f' refers to the component location, and the 'i' refers to the component located
at 'index' relative to the component location.

The component uses automatic limits, and is thus not recommended with MPI/multiprocessing.
In this case, the limits should be set manually, e.g. user1=q and user2=w
options="user1 limits=[0 10] bins=100, user2 limits=[-50 50] bins=200"

A usage example is for instance:
COMPONENT sample = Isotropic_Sqw(...)

COMPONENT sqw = Monitor_Sqw(index=-1, radius=2, yheight=2, bins=128)

This component can be used to generate dynamic structure factors comvolved with
the instrument response, and compare with molecular dynamics results (using e.g. nMoldyn).
The incoming beam (e.g. at the sample) must be monochromatic.

Input parameters

Parameters in boldface are required; the others are optional.
NameUnitDescriptionDefault
user3FLT_MAX
xwidthmWidth of detector.0
yheightmHeight of detector.0
zdepthmThickness of detector (z).0
xminmLower x bound of opening0
xmaxmUpper x bound of opening0
yminmLower y bound of opening0
ymaxmUpper y bound of opening0
zminmLower z bound of opening0
zmaxmUpper z bound of opening0
radiusmRadius of sphere/banana shape monitor0
bins1Number of bins to force for all variables. Use 'bins' keyword in 'options' for heterogeneous bins0
min-1e40
max1e40
index1Index of the component where scattering occurs with respect to the location of the Monitor_Sqw location in the instrument description. The index is usually negative, and should point to e.g. a Isotropic_Sqw, , PowderN, or Single_crystal instance. index=-1 for the previous component.-1
optionsstrString that specifies the configuration of the monitor The general syntax is "[x] options..." (see Descr.).0
filenamestrOutput file name. If not set an automatic file name is used.0
geometrystrName of an OFF file to specify a complex geometry detector0
username30
nowritefile1If set, monitor will skip writing to disk0
AT ( , , ) RELATIVE
ROTATED ( , , ) RELATIVE

Links


[ Identification | Description | Input parameters | Links ]

Generated on 2024-01-03 11:47:43


Last Modified: Wednesday, 03-Jan-2024 19:59:11 CET
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