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McStas: Reflectometer

[ Identification | Description | Input parameters | Links ]

The Reflectometer Instrument

Horizontal reflectometer, multi-angle of incidence


  • Site: Templates
  • Author: Anette Vickery, contact:
  • Origin: KU
  • Date: November 2011


A horizontal reflectometer. The instrument is built of a 2.5 m long mirror and an inclined elliptical guide. The grazing angle is defined by a set of
slits. The sample size is 4cm x 4cm (horizontal sample).
The role of the mirror is to provide an angle of incidence of up to 4 deg and at the same time avoid a direct line of sight to the source.
The reflectivity is the ratio between the direct beam reflected beam intensities. Therefore two simulations are needed to get the reflectivity curve:

Example: mcrun Reflectometer.instr -n1e10 directbeam=1,thetasample=0.4,Qmin=0,Qmax=0.15 -d directbeam
Example: mcrun Reflectometer.instr -n1e10 directbeam=0,thetasample=0.4,Qmin=0,Qmax=0.15 -d reflectedbeam

Input parameters

Parameters in boldface are required; the others are optional.
directbeamIf 1, the sample is a mirror with reflectivity 1. If 0, the mirror reflects like a D2O surface with zero roughness1
Lam_minAAMinimum wavelength emitted by the cold moderator2.0
Lam_maxAAMaximum wavelength emitted by the cold moderator10
deltatheta%The angular resolution2
theta_sampledegThe grazing angle1
defineAngleIf 0, the angle defining slits are wide open. If 1 the angular resolution is deltatheta1
QminAA^-1The minimum value of the interesting Qrange0
QmaxAA^-1The maximum value of the interesting Qrange0.5
straightIf 1, the guide walls are straight1
widthmThe width of the guide in the case of straight guide walls0.05


[ Identification | Description | Input parameters | Links ]

Generated on 2023-09-19 20:01:36

Last Modified: Tuesday, 16-Apr-2024 20:05:20 CEST
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