1. LUMINESCENCE OF COMMON MATERIALS:
APPLICATION TO NATIONAL SECURITY
Adjunct Professor Nigel A. Spooner 1,2
and Dr Barnaby W. Smith 1
1. Defence Science and Technology Organisation
&
2. Institute for Photonics and Advanced Sensing
School of Chemistry and Physics
University of Adelaide

2. Overview:
 Luminescence Techniques for Defence & National Security
 Opportunistic Dosimetry: “New” Luminescence & “New”
Materials
 Example: Salt
 Institute for Photonics and Advanced Sensing (IPAS)
– DSTO/University of Adelaide Centre of Expertise in Luminescence

3. Luminescence Detection of Radiation ExposureLuminescence Detection of Radiation Exposure
Does not rely on the detection of either Ionising Radiation or Radioisotopes - offers a
unique capability in sanitised locations and in the post-event recovery phase
Detection of cDetection of clearedleared ‘‘dirty bombdirty bomb’’
construction or storage sites.construction or storage sites.
•• forensic analysis even whenforensic analysis even when freefree
of isotopic contamination.of isotopic contamination.
Support for UN weapons inspection efforts.Support for UN weapons inspection efforts.
•• forensic analysis of bunkers, buildingsforensic analysis of bunkers, buildings
and laboratories cleaned and refurnishedand laboratories cleaned and refurnished
for nonfor non--nuclear cover activity.nuclear cover activity.
Retrospective population exposureRetrospective population exposure
assessment.assessment.
•• measure ofmeasure of extent of the affected areaextent of the affected area..
•• quantification of radiation exposure over thequantification of radiation exposure over the
affected areaaffected area
PreventionPrevention DetectionDetection
ResponseResponseRecoveryRecovery

4. The population of trapped charge is proportional to the absorbed dose
Conduction Band


radiation
Valence Band
Trap
Ea
thermal or
optical
release
light
emission
Luminescence MechanismLuminescence Mechanism
- enabling quantitative dosimetry

5. Principal Steps in Luminescence AnalysisPrincipal Steps in Luminescence Analysis
Environmental radioactivity measurements are alsoEnvironmental radioactivity measurements are also
made to correct for the natural radiation backgroundmade to correct for the natural radiation background
Including use of a NaI portable GammaIncluding use of a NaI portable Gamma--ray Spectrometry, hereray Spectrometry, here
undergoing calibration at Geosciences Australia, Canberraundergoing calibration at Geosciences Australia, Canberra
Then measured in the LaboratoryThen measured in the Laboratory
PhotonPhoton--Counting Imaging System at ANUCounting Imaging System at ANU
enables analysis of slices and potential rapidenables analysis of slices and potential rapid
assessment of doseassessment of dose--depth profilingdepth profiling
Chemically prepared …
Sample cores are extracted from
common building materials at suspect
sites…

6.  Retrospective nuclear accident dosimetryRetrospective nuclear accident dosimetry
 Art authenticationArt authentication
 Detection of illicit food irradiationDetection of illicit food irradiation
 Atomic bomb radiation effectsAtomic bomb radiation effects
 Chronology of human evolutionChronology of human evolution
 Geomorphology & Soil ScienceGeomorphology & Soil Science
 MegafaunalMegafaunal extinction/climate changeextinction/climate change
Luminescence TechniqueLuminescence Technique
BUT: requires very experienced personnelBUT: requires very experienced personnel
Numerous reported applications in the openNumerous reported applications in the open
literature:literature:

7. Motivation: Naturally-occurring materials are well-studied
 notably quartz and feldspar for luminescence dating
BUT – these may not be present in many scenarios of interest
 urban or industrial locations, vehicles
Instead, Artificial materials may dominate
 which ones can reveal prior exposure to ionising radiation?
Many candidate materials exist but few are sufficiently well-studied
to enable rapid use
 entails compiling, validating and extending current know-how
The complexity of the phenomena means extensive laboratory
work is required to develop Standard Operating Procedures
Extension to “New” Signals and Materials

8. A Key Goal is the testing and extension of protocols on newA Key Goal is the testing and extension of protocols on new
and established materials, to develop Standard Operatingand established materials, to develop Standard Operating
Procedures to enable rapid and flexible analysisProcedures to enable rapid and flexible analysis
Example – Analysis of Brick
Schematic diagram illustrating current
standardised sectioning used to sample
brick for depth-dose measurements
Currently there are no standard protocols, however the Luminescence
Dating community has a large and expanding literature on fired and
unfired materials, and increasing effort in Radioepidemiology
Key Goal – Standard Operating Procedures

9. Dosimetric Materials at Habitations:
 Ceramics
 Porcelain & tiles
 Bricks
 Pottery
 Mortar & Concrete
 Glass
 Salt
 Hard plastics (some?)
 Gyprock
 Mud-based insect nests
 Carbonate materials (limestone,
marble, calcite etc)
 Quartz, Feldspar & Zircon grains
Items carried by people, such as:
• Glass (spectacles, watches etc)
• Jewelry
• Credit cards
• Electronic components
• Hard plastics (some?)
• Some foodstuffs
Opportunistic Dosimetry
UtilisesUtilises materials that fortuitously occur in the incident
environment, or are carried in by people
Contrary to Luminescence Dating, Opportunistic Dosimetry can utilise signals lacking
long-term stability.
This eliminates many complications (from ambient environmental radiation and signals
of formation), and in the CT context this biases against reporting False Positives

10. The Potential of Salt (NaCl) For
Retrospective Dosimetry
19 samples have been collected from around the world
 Australia, UK, Poland, USA, Canada etc.
Types include:
 Rock salt
 Salt damp crystals
 Domestic salt from evaporation of: sea water; saline
lake water saline river water
Our Analyses have included:
1. Emission Spectra
2. Kinetic Analysis
3. TL Sensitivity Changes During Heating
4. OSL & IRSL Dose Response
5. OSL & IRSL Pulse-Annealing Spectra
6. OSL & IRSL Sensitivity Summary
7. Imaged OSL, IRSL, TL

11. TL Emission Spectra
All samples were measured on the University of Adelaide “3D TL Spectrometer”
 No signal-of-formation was observed from any recent-age sample
 Representative spectra are shown, measured at 2K/s; 2Gy beta dose
Prominent TL peaks were seen in the mid-Temp range (150-280ºC), with emissions in UV:
380 nm (3.4 eV), Blue: 440 nm (2.8 eV), Red 590 nm (2.1 eV).
(18) JFK Airport, USA (3) Woolworths Homebrand (10) Himalayan Rock Salt

12. Signal Lifetime: by Variation of Heating Rate Method
0 100 200 300
0
5 10
3

0.01
Glow5n
Glow2n
Glow1bn
Glow05bn
Glow02n
Glow01n
Glow005n
Glow002n
Glow001n
Glow0002n
T1Temperature (ºC)
0.1 deg/s
5 deg/s
0.02 deg/s
0.01 deg/s
0.002 deg/s
2 deg/s
0.2 deg/s
0.5 deg/s
1 deg/s
0.05 deg/s
AreaNormalisedTL
Sample #3; “Woolworths Homebrand” Salt chosen due to representative glow
curve shape and strong Red TL emission
11
12
13
14
15
16
17
18
19
0.0027 0.0029 0.0031 0.0033
1/T
Ln(Tmax
2
/B)
0.002
K/s
1.0 K/s
0.02 K/s
0.2 K/s
100ºC peak (5K/sec)
Lifetime20ºC = 6.6 hours
200ºC peak (5K/sec)
Lifetime20ºC = 0.64 ka
240ºC peak (5K/sec)
E= 1.45 eV
s= 7.9 x 1013
s-1
Lifetime20ºC = 3.9 ka
Data for 100ºC peak
Heating rates 5 K/s – 0.002 K/s

13. Sample
#
Provenance
OSL (after PH 150ºC)
(Cts/Gy/mg)
(1s shine)
IRSL (after PH 150ºC)
(Cts/Gy/mg)*25
(1s shine)
OSL
100 sec shine
(Cts/Gy/mg)
11 Salt Damp Crystals | 48 ||| 5159
12 River Murray Salt Flakes (evap.) | 1602 |||||| 595 |||| 7735
1 Australian Lake Salt |||| |||||| ||||||||||||
13 Ramona's salt |||||| |||||| ||||||||||||||
3
Woolworth's HomeBrand Salt (evap.
seawater)
|||||| 11549 ||||||| 771 |||||||||||||| 29861
19 Sydney, Canada (Huston Texas) ||||||| |||| ||||||||||||||
16 Table Salt, UK, Silver Sachet |||||||||||| 26758 ||||||| 1028 |||||||||||||||||| 39637
14 Evap. Seawater ||||||| ||||| ||||||||||||||||||
15
Table Salt, UK Roadhouse, Blue
Sachet
||||||||||| |||||||||| ||||||||||||||||||
18
JFK Airport, USA (Savannah
Georgia)
|||||||||||| ||||| |||||||||||||||||||||||
20 Halifax Canada ||||||||||||||||| ||||| |||||||||||||||||||||||||||||||
8 Evap. Seawater, SA ||||||||||||| ||||| |||||||||||||||||||||||||||||||
9 Rock Salt (Poland) |||||||||||| |||||||||| |||||||||||||||||||||||||||||||||||
10
Himalayan Crystal Salt ( 250Ma Rock
Salt, Pakistan).
|||||||||||||| ||||||||| |||||||||||||||||||||||||||||||||||||
5 ISM Table Salt |||||||||||||||||||| |||||||| ||||||||||||||||||||||||||||||||||||||||||||||
7 Unbranded Table Salt |||||||||||||||||||||||| |||||||||
|||||||||||||||||||||||||||||||||||||||||||||||||||
||||||
4 Coles Iodised Salt (evap. seawater) |||||||||||||||||||||||||| ||||||||
|||||||||||||||||||||||||||||||||||||||||||||||||||
||||||||||||
2 Saxa Cooking Salt (evap. seawater) ||||||||||||||||||||||||||||| |||||||||
|||||||||||||||||||||||||||||||||||||||||||||||||||
|||||||||||||||
6
Water Softener Salt (unknown comp.)
*
|||||||||||||||||||||||||||||| 65862 |||||||||| 1088
|||||||||||||||||||||||||||||||||||||||||||||||||||
|||||||||||||||||||||||||| 173578

14. The Photon-Counting Imaging System (PCIS)
- Quantitative TL and OSL Imagery

15.  Modified
Minisys reader
 High sensitivity
LN/CCD
detector
 Broad
spectrum high
capture optics
 Optical
stimulation
sources
 Optical
filtering
capability
 Integration
electronics
 Automation
software
systems
Photon-Counting Imaging System (PCIS) Architecture

16. PCIS Luminescence Imaging CapabilityPCIS Luminescence Imaging Capability
The bright inclusions are
mineral grains emitting TL
(acquired by natural irradiation
over the 50 years since firing)
Natural TL from 50 yearNatural TL from 50 year
old house brickold house brick
Aluminum Oxide ChipAluminum Oxide Chip
Red TL integral measured
from 130-260°C following
0.18 Gy dose (equates to 3 x
109 counts/Gy)
QuantitativeQuantitative imaging of irradiated slices, including brick and concreteimaging of irradiated slices, including brick and concrete
•• using a unique facility under development at the RSES, Australiausing a unique facility under development at the RSES, Australian National Universityn National University
Irradiation
Concrete slice (app. 5 mm
square) after 20 Gy dose
applied from direction as
shown
Concrete slice (app. 8 mm
length) after 9 Gy dose applied
from Z (above) direction

17. TL from Australian Lake Salt crystals - PCIS Image
PCIS Image; False Colour,
Unprocessed Data.
No filters; 200-1050nm
spectral range
20Gy beta dose; then TL
measured at 2K/s
The brightest grain shown
here has emitted 5.7 x 107
counts
The total light sum of all
grains is approximately 4.2 x
108 counts
Sensitivity is ~ 2 x 106
counts/Gy/mg for this
salt sample

18. OSL: 470 nm
Stimulation
UV emission: U
340 filter
1st sec Lightsum
=1.8 x 105 cts/Gy
Total Lightsum
~ 3 x 105 cts/Gy
TL 200ºC – 300ºC; 6 Gy beta dose;
No filters (200 – 1050 nm)
TL Lightsum = 1.6 x 108 counts.
Corresponds to 2.5 x 107 cts/Gy
Sample #3
(“Woolworths Homebrand”)
5 mg aliquot
IRSL: 880 nm
Stimulation
Red emission: 3
mm BG 39 filter
1st sec Lightsum
=2.8 x 105 cts/Gy
Total lightsum
~ 2 x 106 cts/Gy

19. Red/Near-IR TL (695-1050 nm)
Sample #3 (“Woolworths Homebrand”); 6 Gy beta dose
TL integrated from 200 – 300ºC; Schott RG 695 filter
TL Lightsum = 5.2 x 107 counts
Corresponds to 1.7 x 106 cts/Gy/mg
Reheat image (note heater plate
incandescence and grain images)

20. IPAS is a transdisciplinary institute incorporating physicists, chemists, biologists
and environmental scientists; Director Professor Tanya Monro
New $80 million Integrated laboratories for research in Photonics and Sensing,
University of Adelaide Nth. Tce campus
Builds on University of Adelaide expertise in soft glass optical fibre research and
silica fibre fabrication
Aims to develop new technologies in areas including:
1. Fibre lasers (medicine & Defence)
2.2. Luminescence for detection of trace materials and environmentalLuminescence for detection of trace materials and environmental dosimetrydosimetry
3. “Smart” fibre sensors using surface chemistry techniques
4. Detection of viruses and cancer biomarkers (functionalised fibre sensors)
5. Evolutionary Biology & Photonics – assess impact of climate change on biodiversity
IPAS Concept & Goals

21. Principal IPAS Activity Areas

22. DSTO / Univ. of Adelaide
Centre of Expertise in Luminescence
(Part of IPAS)

23. Standing and Deployable Capability forStanding and Deployable Capability for
Detection of Prior Radiation ExposureDetection of Prior Radiation Exposure
Principal method: Luminescence (TL or OSL) analyses of materialsPrincipal method: Luminescence (TL or OSL) analyses of materials
(including brick, tiles, porcelain, drywall, concrete and sedime(including brick, tiles, porcelain, drywall, concrete and sediment) tont) to
reveal radiation exposure in excess of natural backgroundreveal radiation exposure in excess of natural background
DSTO / Univ. of Adelaide
Centre of Expertise in Luminescence
A Key Goal is the testing and extension of protocols on newA Key Goal is the testing and extension of protocols on new
and established materials, to develop Standard Operatingand established materials, to develop Standard Operating
Procedures enabling analysis rapidly and flexiblyProcedures enabling analysis rapidly and flexibly

24. Summary
New Material Example:
 Salt has high sensitivity to beta radiation: TL, OSL & IRSL detection
limits are < 1mGy using 10 mg portions of sample
 Salt appears a suitable material for Retrospective Dosimetry
 Australian Luminescence Analysis capacity is currently focussed on the
specialist technique of Optical Dating using OSL from Quartz
 An emergency response will also require utilising less-studied
materials
 Well-defined SOPs for these materials are essential
A key goal of the Centre of Expertise in Luminescence is theA key goal of the Centre of Expertise in Luminescence is the
testing and extension of protocols on new and establishedtesting and extension of protocols on new and established
materials, to develop Standard Operating Procedures andmaterials, to develop Standard Operating Procedures and
enable rapid and flexible analysisenable rapid and flexible analysis