[ Identification | Description | Input parameters | Links ]

# The `Moderator` Component

A simple pulsed source for time-of-flight.

## Identification

- Site:
- Author: KN, M.Hagen
- Origin: Risoe
- Date: August 1998

## Description

    Produces a simple time-of-flight spectrum, with a flat energy distribution

    Example: Moderator(radius = 0.0707, dist = 9.035, focus_xw = 0.021, focus_yh = 0.021, Emin = 10, Emax = 15, Ec = 9.0, t0 = 37.15, gamma = 39.1)

## Input parameters

Parameters in boldface are required; the others are optional.

Name | Unit | Description | Default |
radius | m | Radius of source | 0.07 |
Emin | meV | Lower edge of energy distribution |  |
Emax | meV | Upper edge of energy distribution |  |
dist | m | Distance from source to the focusing rectangle | 0 |
focus_xw | m | Width of focusing rectangle | 0.02 |
focus_yh | m | Height of focusing rectangle | 0.02 |
t0 | mus | decay constant for low-energy neutrons | 37.15 |
Ec | meV | Critical energy, below which the flux decay is constant | 9.0 |
gamma | meV | energy dependence of decay time | 39.1 |
target_index | 1 | relative index of component to focus at, e.g. next is +1 this is used to compute 'dist' automatically. | +1 |
flux | 1/(s cm 2 st meV) | flux | 1 |

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

## Links

- Source code for `Moderator.comp`.

[ Identification | Description | Input parameters | Links ]