Huber diffractometer¶
Huber “psi” diffractometer is installed at CHESS ID4B. Due to four sample-orientation axes and two detector-orientation axes, the psi-circle diffractometer is also known as “4S+2D". The independent motion sample and detector orientation provide nine degrees of freedom to define any vertical diffraction plane.The angle calculations for this diffractometer were shown in the reference [1] [2]. The motor names are shown below in Table 1.
Reference
[1] H. You, J. Appl. Cryst.(1999).32, 614-623 and
[2] W. R. & Levy, H. A. (1967). Acta Cryst. 22, 457–464
Table 1 : Names of the six-circle Huber Diffractometer's motor
| Motor | Commands | Comments |
|---|---|---|
| 2-Theta | tth | horizontal axis for detector arm |
| Theta | th | horizontal axis for sample |
| Chi | chi | sample motor |
| Phi | phi | sample motor |
| Nu | nu | vertical axis for detector, only for psic |
| Mu | mu | vertical axis for sample, only for psic |
| X-direction | samplex | sample motor x-direction |
| Y-direction | sampley | sample motor y-direction |
| Z-direction | samplez | sample motor z-direction |
Table 2 : Motor range and accuracy
| Motor | Range (deg) | Accuracy (arcsec) | Spheres of confusion | Comments |
|---|---|---|---|---|
| Theta | -10/+90? | 0.18? | 30? | vertical theta |
| Delta | 0.18? | 30? | vertical 2theta | |
| mu | -- | 0.18? | 30? | horizontal theta |
| gamma | -- | 0.18? | 30? | horizontal two theta |
| Chi | -- | 0.18? | 30? | with and without cryostat |
| Phi | -- | 0.18? | 30? |