Scintillators or the key to a successful endeavour

01-02-2018

Seven years ago, the ESRF opened a unique laboratory for single crystal film scintillators, a must-have in synchrotron sources. Today they celebrate its success with 172 of these components sold, and an ever increasing demand.

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Beamlines on synchrotrons worldwide need a lot of specific components in order to carry out specialised and state of the art experiments. Scintillators are essential components which make X-rays visible so they can be detected with CCD or CMOS cameras.

The sub-micrometre resolution and high image contrast demanded by today’s experiments require scintillator films with thicknesses in the range 1-20 μm as well as providing high optical quality and uniformity. Thin scintillators minimise degradations due to focusing defects, diffraction and spherical aberrations, therefore boosting the image contrast and spatial resolution. But the sophisticated techniques required to grow such crystals and their high specificity means that very thin single crystal film scintillators are not commercially available.

In April 2010, the ESRF established a unique liquid phase epitaxy facility for single crystal film scintillators. Liquid phase epitaxy is a technique whereby scintillating crystal layers are grown on a solid single crystal substrate immersed in a melt. Its key appeal for synchrotrons is that it produces a homogeneous distribution of dopant activator ions within the film (the host material absorbs X-rays and the dopants emit light). Moreover, the epitaxial growth on a high-density substrate provides a radiation protection for the optics of the X-ray detector system, as well as a rigid support for easy handling and cleaning.

Thierry Martin, in charge of the Detector Unit, explains that “we are very proud of our products and of being able to help other synchrotron sources carry out their scientific programme. We continue developing the scintillators to make them more performing”. Our developments are focused on faster decay time, higher stopping power and better radiation hardness to improve the precision, efficiency and lifetime of X-ray detector respectively.

Top image: A scintillator.