[ Identification | Description | Input parameters | Links ]

# The `Source_Maxwell_3` Component

Source with up to three Maxwellian distributions

## Identification

- Site:
- Author: Kim Lefmann
- Origin: Risoe
- Date: March 2001

## Description

    A parametrised continuous source for modelling a (cubic) source
    with (up to) 3 Maxwellian distributions.
    The source produces a continuous spectrum.
    The sampling of the neutrons is uniform in wavelength.

    Units of flux: neutrons/cm^2/second/ster
    (McStas units are in general neutrons/second)

    Example:  PSI cold source T1=150.42 K / 2.51 AA     I1 = 3.67 E11
    T2=38.74 K / 4.95 AA      I2 = 3.64 E11
    T3=14.84 K / 9.5 AA       I3 = 0.95 E11

## Input parameters

Parameters in boldface are required; the others are optional.

Name | Unit | Description | Default |
size | m | Edge of cube shaped source (for backward compatibility) | 0 |
yheight | m | Height of rectangular source | 0 |
xwidth | m | Width of rectangular source | 0 |
Lmin | AA | Lower edge of lambda distribution |  |
Lmax | AA | Upper edge of lambda distribution |  |
dist | m | Distance from source to focusing rectangle; at (0,0,dist) |  |
focus_xw | m | Width of focusing rectangle |  |
focus_yh | m | Height of focusing rectangle |  |
T1 | K | 1st temperature of thermal distribution |  |
T2 | K | 2nd temperature of thermal distribution | 300 |
T3 | K | 3nd temperature of - - - | 300 |
I1 | 1/(cm**2*st) | flux, 1 (in flux units, see above) |  |
I2 | 1/(cm**2*st) | flux, 2 (in flux units, see above) | 0 |
I3 | 1/(cm**2*st) | flux, 3 - - - | 0 |
target_index | 1 | relative index of component to focus at, e.g. next is +1 this is used to compute 'dist' automatically. | +1 |
lambda0 | AA | Mean wavelength of neutrons. | 0 |
dlambda | AA | Wavelength spread of neutrons. | 0 |

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

## Links

- Source code for `Source_Maxwell_3.comp`.

[ Identification | Description | Input parameters | Links ]