This module simulates an ensemble of supermirror (SM) planes of up to 10 elements. This can be used for the simulation of more complicated guide systems, with branch geometry. For example one can use 4 elements as a normal guide and put one transparent element into this tilted by an angle relative to the main (beam) axis and use it as polarizer. Both sides of the supermirror plates reflect.
The visualisation of neutron paths or collision points available. The module will visualise only first 10000 trajectories or points. Also you can choose a device for visualisation: display, file or both.
 
 
 

Parameter	Description	Command Option
geometry and reflectivity data file	In this file are given: the shape, position, angle, angular spread, 'up' and 'down' reflectivity, absorbtion (see below)	-P
stop at collisions	At this number of collisions it stops and writes out the trajectory. This can be used for localising the coordinates of the 1th, 2nd, 3rd, etc. collisions.	-M
spin quantisation direction	direction of spin quantisation in accordance with input data (e.g.source module)	-Q
visualisation	If 'yes' (1), it writes out the collisions into a file "collisions.dat". Else: it visualises the trajectories	-T
device	Choose the device for visualisation: 1 - display, 2 - file, 3 - display+file	-o
output frame X',Y',Z' [cm]	The position of the output frame origin in the original frame. It represents the translation vector applied to shift the origin of the original (input) frame to the new (output) position.	-r, -s, -t
output angle  horizontal, vertical [deg]	A rotation about the Z axis and then a rotation about the (new)Y axis defines a new orientation for the neutrons written to the output.	-h, -v

The shape and position of the SM elements has to be given in the file "geometry and reflectivity data".

Example:

1       118.75     5.00    -118.75     5.00     -118.75     -5.00     118.75    -5.00    118.75  -2.98   0.00   -90.000    0.000   0.00    0.00       0.00205    0.00206      1.00  100.000      100.000            0.00205    0.00206      1.00  100.000  00.000      ----- A  1 -----

1       181.25     5.00    -181.25     5.00     -181.25     -5.00     181.25    -5.00    418.75  -2.98   0.00   -90.000    0.000   0.00    0.00       0.00205    0.00206      1.00   00.0002375  000.0000           0.00205    0.00206      1.00   00.0002375  00.0000     ----- B  2 -----

1       300.00     5.00    -300.00     5.00     -300.00     -5.00     300.00    -5.00    300.00   2.98   0.00    90.000    0.000   0.00    0.00       0.00205    0.00206      1.00  100.000      100.000            0.00205    0.00206      1.00  100.000  00.000      ----- C  3 -----

1       181.23     5.00    -181.23     5.00     -181.23     -5.00     181.23    -5.00    418.75  -5.89   0.00   -90.917    0.000   0.00    0.00       0.00205    0.00206      1.00  100.000      100.000            0.00097    0.00098      1.00  100.000  00.000      ----- D  4 -----
 

1       300.01     5.00    -300.01     5.00     -300.01     -5.00     300.01    -5.00    300.00  -0.99   0.00    89.620    0.000   0.30    0.00       0.00202    0.0034900    0.90   00.0002375  000.0000           0.00081    0.00082      1.00   00.0002375  00.0000     ----- E  5 -----

1       150.00     5.00    -150.00     5.00     -150.00     -5.00     150.00    -5.00    150.00   1.99   0.00   -89.620    0.000   0.30    0.00       0.00202    0.0034900    0.90   00.0002375  000.0000           0.00081    0.00082      1.00   00.0002375  00.0000     ----- F  6 -----
 

1         2.98   300.00      -2.98   300.00       -2.98   -300.00       2.98  -300.00    300.00   0.00   5.00     0.000   90.000   0.00    0.00       0.00205    0.00206      1.00  100.000      100.000            0.00205    0.00206      1.00  100.000  00.000      ----- G  7 -----

1         2.98   300.00      -2.98   300.00       -2.98   -300.00       2.98  -300.00    300.00   0.00  -5.00     0.000  -90.000   0.00    0.00       0.00205    0.00206      1.00  100.000      100.000            0.00205    0.00206      1.00  100.000  00.000      ----- H  8 -----

1         0.01     0.01      -0.01   181.25       -5.80   -181.16       0.01  -181.25    418.75  -2.98   5.00     0.000   90.000   0.00    0.00       0.00205    0.00206      1.00  100.000      100.000            0.00205    0.00206      1.00  100.000  00.000      ----- I  9 -----

1         0.01   181.25      -5.80   181.16       -0.01   -181.25       0.01    -0.01    418.75  -2.98  -5.00     0.000  -90.000   0.00    0.00       0.00205    0.00206      1.00  100.000      100.000            0.00205    0.00206      1.00  100.000  00.000      ----- J 10 -----

on/off    y1       z1         y2       z2          y3        z3         y4       z4         X      Y      Z       H/°      V/°     h/°     v/°    Up: thetaC    thetaCSM       R     mue*d     mue_incoh*d    Down: thetaC    thetaCSM       R     mue*d     mu_incoh*d     wall label
 

EXPLANATIONS:

1) on/off tells if the wall is active (i.e. you can switch it off)
2) Let us assume that first the 10 elements lie in a plane perpendicular to the beam. Then y_i, z_i i=1,..,4 defines the positions of the element corners (you can also form a triangle if 3 'corners' are co-linear). For all i we have x_i=0. X,Y,Z gives the translation of the element centres to the rigth place in the final geometry and H/° ,   V/° are the Euler rotation angles which define the final normal vector when the element was rotated into the right direction. Now one has a defined geometry.

3) h/°,   v/° is the full width of the rectangular distribution expected for the uncertainties of the plane adjustment.
4) Up/Down: thetaC [rad],    thetaCSM [rad],       R     give the shape of the reflectivity curve for both spin states. R = reflectivity at thetaCSM  (generally R < 1).
5) mue*d  (wavelength dependent),    mu_incoh*d (wavelength independent) give the attenuation coefficients [1/cm] × d i.e. supermirror thickness in cm.
6) 'wall label' is the name given by the user to the walls (no real input)

Last modified: Fri Jul  4 16:51:30 MEST 2003, G. Zs.