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It has been said that we are using the SOLEIL software suite to control the diffractometers at Petra III. Unfortunately there are differences compared with our previous system used at DORIS.
| The hkl vector is rotated, in short: Petra/SOLEIL( 1, 2, 3) corresponds to Doris( 3, 2, 1). In the SOLEIL world h points in the direction of the x-rays and l points upwards. |
The elements of the UB matrix differ by
a factor of 2*PI: UB(PETRA, SOLEIL) = UB(DORIS,RAFIN)*2*PI.
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| The definition of PSI: for DORIS experiments PSI == 0 for
the bisecting setup, for PETRA III PSI is the angle between a
reference direction (1, 0, 0) projected on the plane which diffracts
(normal = Q) and the diffraction plane defined by the incomming and outgoing beam.
Note that there is a way to change the reference direction for the psi calculation: you may store a reference vector in the attribute “parameters” in the diffrac-sim-psi Tango device.
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