Crystal centering in a diamond anvil cell (DAC) for diffraction experiments

What is it about?

A new, accurate and fast optical alignment method of crystals/samples placed in a diamond anvil cell (DAC) has been developed. Other advantages of this method are simplicity and instant visual feedback when aligning the crystal. This method employs Snell’s law, which relates the angles of incidence and refraction of light passing through different media to estimate the crystal position within the DAC by measuring the apparent transverse displacement of the crystal image at various viewing angles .

Featured Image

Photo by Jason D on Unsplash

Photo by Jason D on Unsplash

Why is it important?

The novelty of our approach lies in its reliance on purely optical centering methods, rather than diffraction or absorption techniques. we have confirmed its exceptional efficiency and accuracy, as shown by the consistently low Rint values and high-quality data refinement parameters achieved. This method provides significant safety advantages when working with X-ray and synchrotron sources. It eliminates the need to remove the beam stop and expose the DAC to the primary beam to check the position of the gasket hole or the internal highly absorbing very small crystal for alignment with the detector, reducing the risk of damage to the instrument and potential harm to the user.

Perspectives

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Given the limited availability and high cost of synchrotron beam time, this precise and fast centering procedure is essential to minimize the experimental time and optimize data collection in diffraction experiments.

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