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McStas: ViewModISIS Component

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

The ViewModISIS Component

ISIS Moderators


  • Author: G. Skoro, based on ViewModerator4 from S. Ansell
  • Origin: ISIS
  • Date: February 2016
  • Version:(Unknown)


Produces a neutron distribution at the ISIS TS1 or TS2 beamline shutter front face (or corresponding moderator) position.  
The Face argument determines which TS1 or TS2 beamline is to be sampled by using corresponding Etable file.
Neutrons are created having a range of energies determined by the E0 and E1 arguments.
Trajectories are produced such that they pass through the shutter front face (RECOMENDED) or moderator face (defined by 
xw and yh) and a focusing rectangle (defined by focus_xw, focus_yh and dist). 

Example 1:   ViewModISISver1(Face="TS1_S04_Merlin.mcstas", E0 = E_min, E1 = E_max,
                              dist = 1.7, focus_xw = 0.094, focus_yh = 0.094, modPosition=0,

	MERLIN simulation. 
	modPosition=0 so initial surface is at (near to) the moderator face.
	In this example,  focus_xw and focus_yh are chosen to be identical to the shutter opening dimension.
	dist = 1.7 is the 'real' distance to the shutter front face => This is TimeOffset value (=170 [cm])
	from TS1_S04_Merlin.mcstas file.

Example 2:   ViewModISISver1(Face="Let_timeTest_155.mcstas", E0 = E_min, E1 = E_max,
             modPosition=1, xw=0.196, yh = 0.12, focus_xw = 0.04, focus_yh = 0.094, dist = 0.5)

	LET simulation. 
	modPosition=1 so initial surface is at front face of shutter insert.

	(IMPORTANT) If modPosition=1, the xw and yh values are obsolete. The dimensions of
	initial surface are automatically calculated using "RDUM" values in Let_timeTest_155.mcstas file.

	In this example,  focus_xw and focus_yh are arbitrary chosen to be identical to the shutter opening dimension.

N.B. Absolute normalization: The result of the Mc-Stas simulation will show neutron intensity for beam current of 1 uA.

WARNING: This is a contributed Component.

Input parameters

Parameters in boldface are required; the others are optional.
Name Unit Description Default
Face string Etable filename "TS1_S04_Merlin.mcstas"
E0 meV Lower edge of energy distribution  
E1 meV Upper edge of energy distribution  
modPosition at shutter insert [int] Defines the initial surface for neutron distribution production. Possible values = 0 (at moderator) or 1 0
xw m Moderator width 0.12
yh m Moderator height 0.12
focus_xw m Width of focusing rectangle 0.094
focus_yh m Height of focusing rectangle 0.094
dist m Distance from source surface to the focusing rectangle 1.7
verbose int Flag to output debugging information 0
beamcurrent uA ISIS beam current 1


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

Generated automatically by McDoc, Peter Willendrup <> / Wed Jan 12 15:13:31 2022

Last Modified: Wednesday, 12-Jan-2022 16:13:31 CET
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