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McStas: StatisticalChopper Component

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

The StatisticalChopper Component

Statistical (correlation) Chopper


  • Author: C. Monzat/E. Farhi/S. Rozenkranz
  • Origin: ILL
  • Date: Nov 10th, 2009
  • Version:(Unknown)


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

WARNING: This is a contributed Component.

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 algebraic sign defines the direction of rotation [Hz] Frequency of the Chopper, omega=2*PI*nu  
jitter s Jitter in the time phase 0
delay s Time 'delay'. 0
isfirst it then spreads the neutron time distribution [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 overrides delay [deg] Angular 'delay' 0
verbose 1 Set to 1 to display Disk chopper configuration 0
n_pulse Only if isfirst [1] Number of pulses 1
sequence str Slit sequence around disk, with 0=closed, 1=open positions. NULL or "" will set a default sequence. "NULL"


  • 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 | Output parameters | Links ]

Generated automatically by McDoc, Peter Willendrup <> / Wed Jan 12 15:13:20 2022

Last Modified: Wednesday, 12-Jan-2022 16:13:20 CET
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