Prescott Environmental Luminescence Laboratory
The Prescott Environmental Luminescence Laboratory is an interdisciplinary research facility that brings together research expertise from the Institute for Photonics and Advanced Sensing and Institute for Mineral and Energy Resources.
The Prescott Environmental Luminescence Laboratory provides expertise in the real-time monitoring of radiation fields using radiation-sensitive optical fibres as distributed sensors, and investigations into the detection of prior exposure to radiation, measurements of environmental radiation dose-rates and radioisotope concentrations, and luminescence dosimetry.
Our Optical Dating and Environmental Dosimetry researchers specialise in the physics and applications of luminescence, particularly of minerals and artificial materials, leading to the advancement of luminescence techniques for forensic dosimetry, dose reconstruction (retrospective dosimetry) following radiological incidents, and the application of TL Dating and Optical Dating to a diverse range of questions in Environmental Monitoring, Quaternary Geology, Defence and National Security, Archaeology and Palaeontology.
Strong areas of research also include detection of trace quantities of explosives using microstructured optical fibres, the real-time monitoring of radiation fields using radiation-sensitive optical fibres as distributed sensors, and investigations into the detection of prior exposure to radiation of suitable natural and artificial materials, including opportunistically-available materials in the locality of a radiological event and items fortuitously carried by people in such an area.
Located within the School of Physical Sciences and the Institute for Photonics and Advanced Sensing, the Prescott Environmental Luminescence Laboratory, hosts one of the most comprehensive suites of luminescence research equipment in the world.
The suite includes the world’s most sensitive TL (thermoluminescence) spectrometer, a photon-counting imaging system (PCIS) developed in collaboration with ANU, state-of-the-art TL/OSL (optically-stimulated luminescence) Risø readers, fluorescence analysis facilities, and specialised apparatus for the measurement of luminescence kinetics and signal stability.
Luminescence dosimetry techniques are highly versatile. They are able to accurately measure ages from the present day back 500,000 years and quantify doses as low as a fraction of one day’s background radiation.
Our research is advancing these techniques and further extending the applicability of luminescence analysis.
- Radionuclide measurement
The monitoring and analysis of radionuclide concentrations is an integral part of many dating methods since the deposition and decay of radioactive elements can be tracked as a time-dependent signature.
This allows it to be used to establish the chronology of archaeological and palaeontological sites, and landscape evolution.
The applications vary from natural background radiation estimation for luminescence dating techniques, including single-grain Optical Dating (SG-OSL) and Thermoluminescence (TL) Dating through to the use of man-made nuclides to track erosion and deposition rates, and for retrospective population dosimetry following a radiological event.
The same radionuclide measurement techniques are applicable for the evaluation of mineral processing of ore containing NORM (Naturally Occurring Radioactive Material) nuclides.
It complements other techniques such as those used for groundwater monitoring and has applications in assessing contamination following release of nuclear material.
The equipment in use at the Prescott Laboratory includes coaxial and well configuration HPGe detectors for gamma spectrometry including a state of the art SAGe well detector for small sample measurements.
These are suitable for measurement of low levels of gamma emitting radionuclides in large and small samples respectively.
The size and sensitivity will allow monitoring of laboratory scale mineralogical process research which would not be possible with existing detector types.
The Laboratory also maintains an alpha counting facility for monitoring total alpha radiation and estimating the proportion of primordial Thorium and Uranium in the sample. As an extension of this, the Laboratory has developed spatially resolved alpha decay autoradiography and development of beta counting capability is also underway.
The Laboratory employs personnel experienced with dating, elemental analysis, radiation detection, spectrometry and control of industrial and mineral processes.
- Commercial ServicesWe can support your research and have access to a range of additional and supporting analysis techniques including mass spectrometry, electron microscopy and alpha spectrometry.
The Environmental Luminescence facility brings together an apparatus suite which enables state-of-the-art Geochronology and a great range of research possibilities.
- 3D TL Spectrometer - Interferometer-based, 200-720 nm sensitive range for temperatures up to 600°C - the world's most sensitive TL spectrometer
- Photon-Counting Imaging System (PCIS) - developed in collaboration with ANU and to be transferred to IPAS on long-term loan. An LN-cooled silicon CCD camera is interfaced with a Risø OSL/TL-DA-15 with fast (f0.9) reflective optics to enable exploitation of the full 200-1050 nm sensitive range of the CCD.
- R1: a Risø TL-DA-8 with cooled red (S20) PMT module optimised for red TL.
- R2: a Risø TL/OSL DA-20 with Single-Grain Module with green and IR lasers, dedicated to Single-Grain Optical Dating.
- R3: a Risø TL/OSL DA-20 with fast photon timer module for time-resolved OSL (POSL), and Single-Grain Module with green and IR lasers.
- R4: a Risø OSL/TL-DA-12 for blue TL, with blue/UV (bialkali) PMT, and a 470 nm LED pack for optical stimulation
Elsec Automated OSL/IRSL Reader Type 9010
- A "Single-aliquot" fading chamber for anomalous fading investigations (gift from Prof Dave Huntley, Simon Fraser University, Canada).
- Modified "Elsec" TL glow oven for Kinetics; this is optimised for low count rate TL with a low-noise EMI 9635QA PMT and is capable of heating rates as low as 0.0008 k/s.
- Princeton Instruments Spectrofluorometer (PIXIS 256 detector) enables fluorescence analysis.
- Single-photon avalanche photodiodes (free-space and fibre-coupled).
Sample collection in the field
- A water-cooled "Hilti" coring drill is used for sampling building materials and lithic materials.
- Sediment samples are collected using coring cylinders.
Field dosimetry is performed using
- Two calibrated 27 cubic inch NaI portable gamma-ray spectrometers
- TLD Capsule Dosimetry
Laboratory in-house dosimetry includes
Four LN-cooled high-resolution Ge-gamma ray spectrometers
Six alpha-counters for thick-source alpha counting
In addition, we routinely use external providers for ICPMS/OES, XRF (K), and neutron activation and delayed neutron activation.
Well-equipped sample preparation darkrooms include separate areas for field kit, a "saw room" with masonry saw, Buehler diamond wafering slow-saw and water-cooled coring drill, and a preparation lab dedicated to the extraction of mineral grains; apparatus includes 38 mm and 100 mm micromesh sieve stacks, a facility for batch density separation using lithium heteropolytungstate, Franz magnetic separator, centrifuge, ultrasonic baths, hotplates, precision electronic balances, drying ovens, a tube oven and wide range of laboratory glassware.
Alpha (Am241) and beta (Sr90/Y90) particle irradiations are administered by sources either mounted within the four Risø¸ automated luminescence readers, or in stand-alone automated irradiators. These include two Elsec "6-position" alpha irradiators, an Elsec automated alpha irradiator Type 9010, two Elsec Type 9010automated beta irradiators, two Daybreak automated beta irradiators, and a Littlemore automated beta irradiator. In addition, a set of free standing Sr90/Y90 sources with activities ranging from 0.7 MBq to 1.5GBq and a free-standing 14 MBq Am241 alpha source are available for purpose-configured experiments on Elsec readers or within lead castles.
Ancillary apparatus includes a 1000W Oriel solar simulator, a comprehensive set of Schott, Ealing and Hoya filters, four microprocessor-controlled ovens, lasers (UV to NIR), binocular microscopes, pyroelectric radiometers, and calibrated Si photodiodes.
The Laboratory space exceeds 200 m2, with individual booths and rooms for separate apparatus within a common darkroom, and services including adjustable intensity safe-light options (red and orange), reticulated vacuum, ultra-high purity nitrogen, cooling water and deionised water.
- Key Contact
Prof Nigel Spooner
Institute for Photonics and Advanced Sensing (IPAS)
The University of Adelaide, AUSTRALIA 5005
Telephone: +61 (0)8 831 34852