The module frame renders possible a transformation of the initial co-ordinate system (provided by the former module) by rotation and/or translation and/or mirroring. There are two common applications: One is to get a kink in the beamline by using rotation. The other one is to simulate instruments with geometrical arrangements that are not foreseen by using the provided standard modules. In this case, the co-ordinate system can be changed before this module and changed back after it. Please note that the direction of the gravity effect remains unchanged.
| Parameter Unit |
Description |
Range or Values |
Command Option |
| sequence | One sequence, e.g. rotation - translation - mirroring, covers all options for a transformation. However, in order to provide maximal flexibility and to allow performing the most simple way of transformation, the sequence of rotation(R), transformation(T) and mirroring(M) can be chosen. (The input option "sequence" offers always one out of the six possibilities, default is RTM). | RTM, RMT, TRM, TMR, MTR, MRT | -S |
| rot. angle about z, y, x axis [deg] |
In most cases, only one simple rotation about Z, Y or X axis is needed. This can be done by giving one rotation angle for the corresponding axis while the other two values have to be set to zero (default). IMPORTANT: Positive rotation of a frame means rotation of one positive axis towards a higher index positive axis : +X to +Y, +Y to +Z, +X to +Z . That is: A 90° rotation about the Z axis means X+ rotated on Y+; 90° about the Y axis means X+ rotated on Z+; a 90° rotation about the X axis means Y+ rotated on Z+. Negative angle (e.g. -90°) means rotation in opposite direction. For multiple rotations, it is important to realize that rotation operations are not commutative. On the other hand, three successive rotations of a 3D frame about e.g. Z, Y and X axes cover all possible orientations. This module uses the the following sequence: the first rotation performed is always around the Z axis (horizontal plane), this is followed by a rotation about the new Y (vertical plane containing new X) and finaly about the new X (beam) axes. | -H, -V, -A | |
| Translation x, y, z [cm] |
The input parameters are the components x, y, z of the translation vector which shifts the origin of the coordinate system. This shift is not meant as a real pysical operation, therefore the neutron time-of-flight is not recalculated according to the length of this vector. |
-x, -y, -z | |
| mirror at yz, xz, xy plane |
Mirroring relative to the YZ , ZX or XY planes means: x changes to -x, y to -y and z to -z resp. The three mirror operations can be performed alltogether. Two simultaneous mirroring operations mean a rotation of 180°. | 'yes', 'no' | -i, -j, -k |
Last modified: 2021-07-21 K. Lieutenant