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PHY 651 MODERN INSTRUMENTATION. TEAM: MA, XU & NSANZINEZA, IBRAHIM. SCINTILLATION DETECTOR GAMMA RAY SPECTRA OF Co-60 AND Cs-137. SCINTILLATORS PHOTOMULTIPLIER TUBES SOURCES: Cobalt-60 and Cesium-137. Scintillation detector. Scintillators
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TEAM: MA, XU & NSANZINEZA, IBRAHIM
SCINTILLATION DETECTOR GAMMA RAY SPECTRA OF Co-60 AND Cs-137
SCINTILLATORS • PHOTOMULTIPLIER TUBES • SOURCES: Cobalt-60 and Cesium-137
Scintillators -Material which exhibits the property of luminescence when excited by ionizing radiation -Absorb energy of incoming particle reemit in the form of a small flash of light scintillate
Types of Scintillators • Organic • Liquid • Economical • messy • Solid • Fast decay time • long attenuation length • Emission spectra • Inorganic • Anthracene • Unused standard • NaI, CsI • Excellent g resolution • Slow decay time • BGO • High density, compact
γ-rays interact with matter The photoelectric effect, The Compton interaction, Pair production
g e− Electrodes Anode Photocathode Dynodes Photomultiplier Tube, PMT
Measurements Three cases Background Spectrum Cobalt-60 specrum Cesium-137spectrum
Measurements(Cont.) -Use NaI( Tl) and CsI(Tl) -Consider HV: 600V, 700V, 800V, 900V, 1000V -Acquire data using OXFORD WIN MCA -Accumulate data for 10minutes -Save data in ANS and ASC formats - Change to png format using GNUPLOT
Next? -Features in Spectrum backscatter Compton edge Photopeak -Find FWHM of photopeak -Estimate resolution of Detector
For Cs-137 R=11% For Co-60 Peak E=1.17MeV, R=6.4% Peak E=1.33MeV, R=5.5%
Acknowledgments Thanks to Professor Marina Artuso Thanks to Professor Mountain, Raymond