Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006 The XRF method: Development and...
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Transcript of Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006 The XRF method: Development and...
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
The XRF method: Development and
Applications
Ch. Zarkadas and A.G. Karydas
N.C.S.R. “Demokritos”, Institute of Nuclear Physics,
Aghia Paraskevi, 15310, Athens Greece
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
Outline
The X-ray Fluorescence technique
XRF facilities at the I.N.P of “Demokritos”
Conclusions
Applications
State of the art instrumentation
Κ L M
Nucleus
E0
Ka
Electrons
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
Physics of the XRF technique
A typical ΧRF setup
Detector
Preamp
Amp
ADC MCA
Computer
Source
Sample
Substrate
X-rays
Αρι
θμός
γεγ
ονότ
ων
Ενέργεια (keV)
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
State of the art instrumentation
Rotating anode (18kW)
X-ray Tubes
High power (3kW)
Low power (50W)
X-ray DetectorsLN cooled
Si(Li)
Thermoelectrically cooledSDD, Si-PIN
Digital Electronics
X-ray OpticsPolycapillary
lenses
HOPG crystals
Provide/Enable:•Intense exciting X-ray beams
•Energy resolution down to 135 eV
•High count rate handling capabilities (106 cps!!!!)
•Low Z detection (B,C,O,N)
•Formation of focused intense beams – microbeams (10μm-100μm)
•In depth analysis combining two polycapillaries (3D confocal XRF)
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
XRF instruments at the I.N.P STXRF (Secondary Target XRF)
Detector guide
Sample
Filters
Crystal
Secondary target Be window
Shutter
Provides:•Selectable almost monochromatic excitation
•Polarized doubly scattered continuum
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
XRF instruments at the I.N.P TXRF (Total Reflection XRF)
0 2 4 6 8 10 12 14 16 18 200,0
5,0x102
1,0x103
1,5x103
2,0x103
2,5x103
Μο(
Κα)
Y(Κ
α)Sr
(Κα)
Se(Κ
α)
Zn(
Κα)
Ni(
Κα)
Ti(
Κα)
Cr(
Κα)
Ca(
Κα)
Si(Κ
α)
Αρι
θμός
γεγ
ονότ
ων
Energy (keV)10 20 30 4010
0
101
102
103
Μο(Kβ)
Μο(Kα)
Σκεδαζόμενη ακτινοβολίαAr(Kα)
Αρι
θμός
γεγ
ονότ
ων
Ενέργεια (keV)
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
The demokritos portable milli beam XRF spectrometer
Features:
•Rh, side window, 50W, air cooled tube, 75μm Be window
•PIN diode detector, FWHM = 165 eV MnKα, 500 μm thickness
•Electromagnetic beam shutter
•Rotatable filter wheel
•Lasers for sample positioning
•Collimating parts, Beam spot
~ 3mm at sample position
•Control unit
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
Handheld XRF spectrometer (under design)
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
The demokritos μXRF spectrometer
10mm2 SDD
30W, Rh anode μfocus (50μm x 50μm) X-ray
tube
Camera
Polycapillary lens
X-Y-Z stage 10μm steps
Polycapillary lens 41MLS03Focal spot 60-80 μmOptimized for higher energiesOutput focal distance 21.2 mmMinimum Halo effectHe filled
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
Biomedical Applications (I) Determination of Trace Elements in Human
Blood serum
2 4 6 8 10 12 14 16 18101
102
103
104
105
106
Ar ξ=38.3 mg/cm2
V=40 kVi=20 mAt=6000 sec
Br
Se
Ga*
ZnCuFe
CaK
Cl
S
Scattered peaksC
oun
ts
Energy (keV)
Y Secondary Target Excitation
MDL’s: 12 ppb
Yttrium secondary target excitation
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
8 9 10 11 120
200
400
600
Pt-L Pt-L
Br-KZn-K
Se-K
Cu-KZn-K
Cou
nts
Energy (keV)
3 hrs 600 s 10 s
Biomedical Applications (II) Determination of cis-Pt in mice Blood
Yttrium secondary target excitation
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
Biomedical Applications (III) Determination of Uranium in urine
10 11 12 13 14 150
1x103
2x103
3x103
Cou
nts
Br
Se
U
Br
Se
Pb
Energy (keV)
10 11 12 13 14 150
2x103
4x103
6x103
MDL’s: 250 ppt
Total reflection + chemical treatment
5 ppb U
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
2 4 6 8 10 12 14 16 18 20101
102
103
104
105
V=50 kVi=30 mAt=1000 sec
S
Ar
Br
Sr
Ga*
Ca
K
Cl
Si Scattered peaks
Cou
nts
Εnergy(keV)
Environmental Applications (I) Determination of Trace Elements in
potable water
Bottled water
Tap water
Total reflection, direct measurement
MDL’s: 6 ppb
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
Environmental Applications (II) Determination of Trace Elements in
airborne particulates The case of “Sahara rain”
Mo secondary target excitation
2 4 6 8 10 12 14
200
400
600
800
1000
1200
1400
1600
1800
2000
Sr-K
Rb-K
Pb-L
Pb-L
Ga-K
Zn-K
Cu-K
Ni-K
Fe-K
Mn-K
Cr-K
Ti-K
Ca-K
K-K
Co
un
tsEnergy (keV)
Net Spectrum
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
Cultural Heritage Applications (I) Determination of pigments on
marble statues
Egyptian Blue
Ochre
Organic
Jarosite
Orpiment
Ochre
Ochre
Ochre
Ochre
Sulfur Flower
Sulfur
Organic Black
Orpiment
Celadonite
Celadonite
Orpiment (As2S3)
Egyptian Blue (CuCaSi4O10)
0.0 0.1 0.2 0.3 0.4 0.5
5000
10000
15000
20000
25000
30000
Cou
nts
(a.u
.)
Depth (mm)
Hg Fe Ca
Linear scan in a paint layer section
10-15 μm cinnabar20-30 μm red ochre
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
10-15 μm Egyptian Blue100-140 μm Black30-50 μm Kaolinite10-20 μm Cinnabar
0.0 0.1 0.2 0.3 0.4 0.5 0.6
0
5000
10000
15000
20000
25000
30000
35000
Cou
nts
(a.u
.)
Depth (mm)
Cu Ca Fe Hg
Linear scan in a paint layer section
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
34 gold jewels
Benaki Museum-10 0 10 20 30 40 50
40
50
60
70
80
90
100
110
Au+Ag=100%
Au+Ag=97%
Orientalizing [3] Archaic [5] Classic [3] Hellenistic [18] Roman [5]
A
BBenaki Museum gold jewels
7th-2nd Cent. B.C.
Au
(%)
Ag (%)
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
Cultural Heritage Applications (II) Chemical discrimination of gold
alloys
Rh direct excitation
0 5 10 15 20 25 30100
101
102
103
104
105
Sn-K
Rh-
K
Pb-L
Pile
Up
Pb-L
Cu-
K
Zn-
K
Ni-
K
Cu-
K
Fe-K
Sn-L
Cou
nts
Energy
BCR D Sn 10% Pb 10% Measuring time: 5 sec
μXRF spectrum of a tin-lead Copper alloy
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
Summary - Conclusions - Perspectives
Workshop PET/SPECT/RADIO-ISOTOPES in Greece
26 June 2006
X-ray Fluorescence is nowadays a dynamic and well established technique for quantitative and/or qualitative analysis (non destructive if necessary)
A new generation of XRF spectrometers is currently available at Demokritos
In depth analysis has been already achieved (3D confocal setups) and will be the trend in the near future
Offers multielemental and sensitive analysis in a wide variety of different samples in the interdisciplinary field