[ Identification | Description | Input parameters | Links ]

# The `Guide_honeycomb` Component

Neutron guide with gravity and honeycomb geometry. Can be channeled and focusing.

## Identification

- Site:
- Author: G. Venturi
- Origin: ILL (France).
- Date: Apr 2003

## Description

    Models a honeycomb guide tube centered on the Z axis. The entrance lies
    in the X-Y plane. Gravitation applies also when reaching the guide input
    window. The guide can be channeled (hexagonal channel section; nslit,d parameters).
    The guide coating specifications may be entered via different ways (global,
    or for each wall m-value).
    For details on the geometry calculation see the description in the McStas
    reference manual.

    Example: Guide_honeycomb(w1=0.1, w2=0.1, l=12,
    R0=0.99, Qc=0.0219, alpha=6.07, m=1.0, W=0.003, nslit=1, d=0.0005)

## Input parameters

Parameters in boldface are required; the others are optional.

Name | Unit | Description | Default |
w1 | m | Width at the guide entry |  |
w2 | m | Width at the guide exit. If zero, sets w2=w1. | 0 |
l | m | length of guide |  |
R0 | 1 | Low-angle reflectivity | 0.995 |
Qc | AA-1 | Critical scattering vector | 0.0218 |
alpha | AA | Slope of reflectivity | 4.38 |
m | 1 | m-value of material. Zero means completely absorbing. | 1.0 |
W | AA-1 | Width of supermirror cut-off | 0.003 |
nslit | 1 | Number of horizontal channels in the guide (>= 1) [1] | 1 |
d | m | Thickness of subdividing walls [0] | 0.0005 |
mleftup | 1 | m-value of material for leftup. oblique mirror | -1 |
mrightup | 1 | m-value of material for rightdown. oblique mirror | -1 |
mleftdown | 1 | m-value of material for rightdown. oblique mirror | -1 |
mrightdown | 1 | m-value of material for leftup. oblique mirror | -1 |
mleft | 1 | m-value of material for left. vertical mirror | -1 |
mright | 1 | m-value of material for right. vertical mirror | -1 |
G | m/s2 | Gravitation norm. 0 value disables G effects. | 0 |

AT ( | , | , |  | ) RELATIVE |  |
ROTATED ( | , | , |  | ) RELATIVE |

## Links

- Source code for `Guide_honeycomb.comp`.

[ Identification | Description | Input parameters | Links ]