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McStas: Virtual_mcnp_ss_Guide

[ Identification | Description | Input parameters | Links ]

The Virtual_mcnp_ss_Guide Component

Neutron guide initiated using Virtual_mcnp_ss_input.comp, and replacing Virtual_mcnp_ss_output.comp - see examples//Test_SSR_SSW_Guide.instr


  • Site:
  • Author: Esben klinkby and Peter Willendrup
  • Origin: Risoe-DTU
  • Date: Marts 2012


Based on Kristian Nielsens Guide.comp
Models a rectangular guide tube centered on the Z axis. The entrance lies
in the X-Y plane.
The component must be initiated after Virtual_mcnp_ss_input.comp,
and replaces Virtual_mcnp_ss_output.comp  - see examples/Test_SSR_SSW_Guide.instr.
The basic idea is, that rather than discarding unreflected (i.e. absorbed)
neutrons at the guide mirrors, these neutron states are stored on disk.
Thus, after the McStas simulation a MCNP simulation can be performed based
on the un-reflected neutrons - intended for shielding studies.
(details: we don't deal with actual neutrons, so what is transferred between
simulations suites is neutron state parameters: pos,mom,time,weight. The latter is
whatever remains after reflection.

For details on the geometry calculation see the description in the McStas
reference manual.
The reflectivity profile may either use an analytical mode (see Component
Manual) or a 2-columns reflectivity free text file with format
[q(Angs-1) R(0-1)].

Example: Virtual_mcnp_ss_Guide(w1=0.1, h1=0.1, w2=0.1, h2=0.1, l=2.0,
R0=0.99, Qc=0.021, alpha=6.07, m=2, W=0.003

Upcomming in 2012 based on ESS shielding
Validated by: D. Ene & E. Klinkby

This component does not work with gravitation on. Use component Guide_gravity then
(doesn't work with SSR/SSW unfortunately)

Input parameters

Parameters in boldface are required; the others are optional.
reflectstrReflectivity file name. Format 0
w1mWidth at the guide entry
h1mHeight at the guide entry
w2mWidth at the guide exit
h2mHeight at the guide exit
lmlength of guide
R01Low-angle reflectivity0.99
QcAA-1Critical scattering vector0.0219
alphaAASlope of reflectivity6.07
m1m-value of material. Zero means completely absorbing.2
WAA-1Width of supermirror cut-off0.003


[ Identification | Description | Input parameters | Links ]

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

Last Modified: Wednesday, 03-Jan-2024 19:59:10 CET
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