How it works
Simulated experiment
A principle of a neutron Laue diffractometer is extremely simple. When a single crystal is placed in a white beam it diffracts neutrons in many directions. The diffracted beams which hit the detector surface produce so called Bragg dots of varying intensities depending on the atomic structure of the material. The shape of the Bragg spots tells us about the quality of the sample. The location and intensity of the spots tells us about symetry of the lattice and the structure of crystal.
How fast is CYCLOPS ?
This movie was recorded during the very first tests of the instrument in June 2009. It shows that exposures as short as a few seconds are enough to get excellent Laue patterns from a sample of a few mm3 in size. For example, the patterns shown in the movie clearly demonstrate that the test crystal is twinned, all Bragg spots being splitted in two. In other words a few seconds were enough to assess the quality of the sample.
Low temperatures with CYCLOPS
This movie was recorded during an experiment down to 50 mK. The sample was mounted at the cold end of a dilution insert, and then inserted in the helium cryostat of CYCLOPS.
Laue patterns where recorded during the temperature decrease thus providing a quasi real-time observation of the appearance and evolution of satellites while the sample underwent two successive phase transitions.
What you see in the movie is, in fact, a mixture of two experiments. During the 50 mK experiment the target temperature was easly reached but the sample was destroyed due to an improper handling.