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McStas: Pol_bender

[ Identification | Description | Input parameters | Links ]

The Pol_bender Component

Polarising bender.

Identification

  • Site:
  • Author: Peter Christiansen
  • Origin: RISOE
  • Date: August 2006

Description

Based on Guide_curved written by Ross Stewart.
Models a rectangular curved guide tube with entrance centered on the Z axis.
The entrance lies in the X-Y plane.  Draws a true depiction
of the guide with multiple slits (but without spacers), and trajectories.
It relies on similar physics as the Monochromator_pol.
The reflec function and parameters are passed to this component to
give a bigger freedom.
The up direction is hardcoded to be along the y-axis (0, 1, 0)

The guide is asummed to have half a spacer on each side:
slit1  slit2  slit3
|+     ++     ++     +|
|+     ++     ++     +|
<---------------------> xwidth
<------> xwidth/nslit (nslit=3)
<> d

The reflection functions and parameters defaults as follows:
Bot defaults to Top, Left defaults to Top, Right defaults to left.
Down defaults to down and up defaults to up for all functions and
Top(Up and Down) defaults to StdReflecFunc and {0.99,0.0219,6.07,2.0,0.003}
which stands for {R0, Qc, alpha, m, W}.

Example:
Pol_bender(xwidth = 0.08, yheight = 0.08, length = 1.0, radius= 10.0,
nslit=5, d=0.0, endFlat=0, drawOption=2,
rTopUpPar={0.99, 0.0219, 6.07, 3.0, 0.003},
rTopDownPar={0.99, 0.0219, 6.07, 1.0, 0.003})

See also the example instruments Test_Pol_Bender and
Test_Pol_Bender_Vs_Guide_Curved (under tests).

%BUGS
This component has been against tested Guide_curved and found to
give the same intensities. Gravity option has not been tested.

GRAVITY: YES (when gravity is along y-axis)

Input parameters

Parameters in boldface are required; the others are optional.
NameUnitDescriptionDefault
rTopUpFunc1Top reflection function for spin up (q, *par, *reflecProb)StdReflecFunc
rTopDownFunc1Top reflection function for spin down (q, *par, *reflecProb)StdReflecFunc
rBotUpFuncrTopUpFunc
rBotDownFuncrTopDownFunc
rLeftUpFuncrTopUpFunc
rLeftDownFuncrTopDownFunc
rRightUpFuncrLeftUpFunc
rRightDownFuncrLeftDownFunc
rTopUpPar1Parameters for rTopUpFunc{0.99,0.0219,6.07,2.0,0.003}
rTopDownPar1Parameters for rTopDownFunc{0.99,0.0219,6.07,2.0,0.003}
rBotUpParrTopUpPar
rBotDownParrTopDownPar
rLeftUpParrTopUpPar
rLeftDownParrTopDownPar
rRightUpParrLeftUpPar
xwidthmWidth at the guide entry
yheightmHeight at the guide entry
lengthmlength of guide along center
radius
G9.8
nslit1Number of slits1
dmWidth of spacers (subdividing absorbing walls)0.0
debug1if debug > 0 print out some internal parameters0
endFlat1If endflat>0 then entrance and exit planes are parallel.0
drawOption11: fine(all slits/90 points per arc), 2: normal (max 20/40), 3: rough (max 5/10)1
AT ( , , ) RELATIVE
ROTATED ( , , ) RELATIVE

Links


[ Identification | Description | Input parameters | Links ]

Generated on 2024-01-03 11:47:43


Last Modified: Tuesday, 16-Apr-2024 20:05:22 CEST
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