Sample environment

To avoid absorption and scattering of X-rays on air, the whole camera length, including the sample chamber, is evacuated. Samples therefore need to be either vacuum-tolerant or put into a vacuum-tolerant container.

Liquid samples

Aqueous samples are usually put into borosilicate capillaries of ~ 1.5 mm outer diameter and 0.01 mm wall thickness. One end of the capillaries is sealed with flame before filling the sample. The other end is closed either by hot glue, two-component epoxy glue or molten together by flame.

Solid samples

Solid samples of typically 5×5 mm² cross-section and around 1 mm thickness are fixed on sample carrier plates, typically using some putty (e.g. Blu Tack)

Powder samples

If vacuum-sensitive, powders can also be filled into borosilicate capillaries. Otherwise, they can also be mounted on sample carrier plates, between two layers of self-adhesive tape (Scotch® Magic™ Tape has been found to be the best).

In situ measurements

Various aspects of the sample environment can be controlled:

• temperature of the capillaries can be set by circulating water in the capillary block, using a Haake thermostat
• magnetic field of approx. 0.7 T can be applied using a magnetic_sample_holder.jpg special sample holder
• samples can be illuminated using a Schott KL2500LED light source
• a flow-through capillary system is available, making it possible to circulate the sample in a fixed capillary, enabling the continuous sampling of a reaction medium outside the sample chamber