1. What are the sample stages available at the Powder Diffraction beamline?
The X-ray diffraction patterns from samples prepared in capillaries give the highest peak resolution, therefore this form of sample preparation is the most commonly used in user experiments. The capillaries are mounted in standard goniometer heads (two tilt and two translation axes). The goniometer heads can be attached to a single sample spinner (Figure 1).  

Figure 1. Single sample spinner


2. Is the heating and cooling ancillary equipment compatible with the single spinner?
The single sample spinner is completely compatible with the cryostream and hot-air blower ancillaries on the beamline and the spinning speed is adjustable.

3. Can users construct and bring their own sample stages?
Users' own sample stages can be used, providing they fit within the constraints of the omega circle.  Refer to 'Diffractometer mounting space for sample stages.pdf' (click here to download 111kb pdf for this information).

4. What can I mount my sample stage on?
Sample stages requiring centering adjustment may be mounted to a Huber 5102.20 XY stage (Figure 3) which is positioned on the omega circle. Each axis on the X-Y stage is capable of plus or minus 15 mm translation and can be controlled via the beamline control station. Samples not requiring this additional adjustment can be mounted directly to the omega circle, as in 'Diffractometer mounting space for sample stages.pdf' (see above to download this file). For an engineering drawing of the XY-stage and also information on the hole pattern that may be used for mounting sample stages, see 'XY-stage_DRAWING.pdf' (click here to download 105kb pdf).

Figure 3. X-Y stage mounted on the omega circle showing the two axes of translation. User-constructed stages can be mounted as shown in the two examples below (Fig. 4a & b).


5. How far is it from the face of the mounting to the beam?

The distance from the face of the omega circle to the beam centre is 250 mm.  The distance from the face of the XY-stage when mounted on the omega circle to the beam centre line is 188 mm. An example of a user constructed stage can be seen in Figure 4 and is shown as a guide only.

Figure 4a. Images 4a and 4b show examples of user-constructed sample stages

Figure 4b.


6. How can I get through hundreds of samples in a short time?

A high-throughput stage (Figure 5) is available and is capable of measuring up to 40 powder samples consecutively in a single EPICS scan programme. The samples are loaded in plates or cassettes which are inserted into the stage and can be changed rapidly with minimal re-alignment required.   This stage allows data to be acquired from up to 1000 samples per day.  X-ray transparent films (Kapton or Mylar) are fixed to either side of the cassettes to keep the powders within each sample well.  Particle statistics are improved during data collection via rocking of the omega axis, however particle size should be as small as possible to maximise the data quality.  Users should prepare these cassettes prior to arriving at the synchrotron in order to maximise the productivity of the beamtime; notes on preparing the samples are available on the page Sample types for Powder Diffraction


Figure 5. High-throughput stage mounted on the diffractometer.