[ Identification | Description | Input parameters | Output parameters | Links ]

# The `Selector` Component

velocity selector (helical lamella type) such as V_selector component

## Identification

- Author: Peter Link, Andreas Ostermann
- Origin: Uni. Gottingen (Germany)
- Date: MARCH 1999
- Version: 1.8

## Description

    velocity selector (helical lamella type)

    Example: Selector(xmin=-0.015, xmax=0.015, ymin=-0.025, ymax=0.025, len=0.25,
               num=72,width=0.004,radius=0.12,alfa=48.298,feq=500)
    These are values for the D11@ILL Dornier 'Dolores' Velocity Selector (NVS 023)

    %VALIDATION
    Jun 2005: extensive external test, problems are being solved at the moment

    %BUGS
    for transmission calculation, each neutron is supposed to be in the guide centre

## Input parameters

Parameters in boldface are required; the others are optional.

Name | Unit | Description | Default
--- | --- | --- | ---
xmin | m | Lower x bound of entry aperture | -0.015
xmax | m | Upper x bound of entry aperture | 0.015
ymin | m | Lower y bound of entry aperture | -0.025
ymax | m | Upper y bound of entry aperture | 0.025
len | m | rotor length | 0.25
num | 1 | number of spokes/lamella | 72
width | m | width of spokes at beam-center | 0.0004
radius | m | radius of beam-center | 0.12
alfa | deg | angle of torsion | 48.298
feq | 1/s | frequency of rotation | 500

## Links

- Source code for `Selector.comp`.
- See also Additional notes March 1999 and Jan 2000.

[ Identification | Description | Input parameters | Output parameters | Links ]