[ Identification | Description | Input parameters | Links ]

# The `StatisticalChopper` Component

Statistical (correlation) Chopper

## Identification

- Site:
- Author: C. Monzat/E. Farhi/S. Rozenkranz
- Origin: ILL
- Date: Nov 10th, 2009

## Description

    This component is a statistical chopper based on a pseudo random sequence that the user
    can specify. Inspired from DiskChopper, it should be used with SatisticalChopper_Monitor component.

    Example: StatisticalChopper(nu=1487*60/255) use default sequence

## Input parameters

Parameters in boldface are required; the others are optional.

Name | Unit | Description | Default |
radius | m | Radius of the disc | 0.5 |
yheight | m | Slit height (if = 0, equal to radius). Auto centering of beam at half height. | 0 |
nu | Hz | Frequency of the Chopper, omega=2*PI*nu |  |
jitter | s | Jitter in the time phase | 0 |
delay | s | Time 'delay'. | 0 |
isfirst | 0/1 | Set it to 1 for the first chopper position in a cw source | 0 |
abs_out | 0/1 | Absorb neutrons hitting outside of chopper radius? | 1 |
phase | deg | Angular 'delay' (overrides delay) | 0 |
verbose | 1 | Set to 1 to display Disk chopper configuration | 0 |
n_pulse | 1 | Number of pulses (Only if isfirst) | 1 |
sequence | str | Slit sequence around disk, with 0=closed, 1=open positions. | "NULL" |

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

## Links

- Source code for `StatisticalChopper.comp`.
- R. Von Jan and R. Scherm. The statistical chopper for neutron time-of-flight spectroscopy. Nuclear Instruments and Methods, 80 (1970) 69-76.

[ Identification | Description | Input parameters | Links ]