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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
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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
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Κ L M Nucleus E0E0 Ka Electrons Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006 Physics of the XRF technique
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A typical ΧRF setup Detector Preamp Amp ADC MCA Computer Source Sample Substrate X-rays Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006
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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 Detectors LN cooled Si(Li) Thermoelectrically cooled SDD, Si-PIN Digital Electronics X-ray Optics Polycapillary lenses HOPG crystals Provide/Enable: Intense exciting X-ray beams Energy resolution down to 135 eV High count rate handling capabilities (10 6 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)
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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
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Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006 XRF instruments at the I.N.P TXRF (Total Reflection XRF)
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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 MnK α, 500 μm thickness Electromagnetic beam shutter Rotatable filter wheel Lasers for sample positioning Collimating parts, Beam spot ~ 3mm at sample position Control unit
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Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006 Handheld XRF spectrometer (under design)
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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 41MLS03 Focal spot 60-80 μm Optimized for higher energies Output focal distance 21.2 mm Minimum Halo effect He filled
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Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006 Biomedical Applications (I) Determination of Trace Elements in Human Blood serum MDL’s: 12 ppb Yttrium secondary target excitation
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Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006 Biomedical Applications (II) Determination of cis-Pt in mice Blood Yttrium secondary target excitation
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Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006 Biomedical Applications (III) Determination of Uranium in urine MDL’s: 250 ppt Total reflection + chemical treatment 5 ppb U
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Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006 Environmental Applications (I) Determination of Trace Elements in potable water Bottled water Tap water Total reflection, direct measurement MDL’s: 6 ppb
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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
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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 Sulfur Flower Sulfur Organic Black Orpiment Celadonite Orpiment (As2S3) Egyptian Blue (CuCaSi4O10)
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Linear scan in a paint layer section 10-15 μm cinnabar 20-30 μm red ochre Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006
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10-15 μm Egyptian Blue 100-140 μm Black 30-50 μm Kaolinite 10-20 μm Cinnabar Linear scan in a paint layer section Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006
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34 gold jewels Benaki Museum Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006 Cultural Heritage Applications (II) Chemical discrimination of gold alloys Rh direct excitation
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μXRF spectrum of a tin-lead Copper alloy Workshop PET/SPECT/RADIO-ISOTOPES in Greece 26 June 2006
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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
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