Low temperature (20-300 K) thermoluminescence spectrum of Fluorite. The data are shown in a 3D format (left) and as a contour map (right). The sudden discontinuities seen horizontally in the right hand graph are thermoluminescence peaks. Such graphs allow us to probe the defect structure of minerals and understand more about how defect form and cluster.
The St Andrews Facility for the Luminescence of Minerals is now reopened after being relocated to its new purpose-built luminescence suite. The new luminescence facility has the instrumentation it previously had added to a darkened red-light prep area to allow analysis of light-sensitive samples.
The bespoke RLTLCL system has been moved over from the Irvine Building in the East of St Andrews to the new facility in the Purdie Building on the University’s North Haugh science site. In the move, the system was refurbished, replacing the vacuum system and resolving glitches in the operation of the low temperature (20-300 K) stage. The Helium compressor and the closed-cycle chiller units are now housed in a soundproof and heatproof enclosure meaning that their operation is far more silent than before. The software has also been upgraded and improved to make the interface more intuitive and to allow far more easy remote operation.
The ns time-resolved luminescence system and the Uv-Visible spectrophotometer have also been moved across.
The RLTLCL system was built at St Andrews from a chassis designed and built by Peter Townsend in Engineering at Sussex University. The detectors and software were integrated by Adrian Finch at St Andrews in 2007 using a NERC technology development grant. It allow the spectroscopy of luminescence of solid samples to be measured at temperatures from 20 K to 400°C. Luminescence is measured from 250 to 800 nm using x-ray, heat, electron and laser excitation or stimulation. The detectors can be gated allowing time-resolved spectroscopically resolved luminescence measurements. Using this methods we have measure the thermoluminescence spectra of minerals, and also the spectroscopically, time-resolved Optically Stimulated Luminescence of synthetic alumina.