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Detection of Radiation using Scintillation Detectors. Brynle Barrett 3 rd Year Advanced Lab Project. Motivation. Construct two scintillation detectors Detect radiation from sources in lab and from cosmic rays (muons) Use to measure cosmic ray flux at local latitude.
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Detection of Radiation using Scintillation Detectors Brynle Barrett 3rd Year Advanced Lab Project
Motivation • Construct two scintillation detectors • Detect radiation from sources in lab and from cosmic rays (muons) • Use to measure cosmic ray flux at local latitude
What are Scintillation Detectors? • Some materials give off light when bombarded with radiation NaI (Th) • Can use scintillation light as a trigger • Consist of three pieces: Photo multiplier tube Light guide Scintillator
Dynodes (secondary e- emission) Reflector Emitted electron Anode +200V +600V Glass +50V Coaxial out Scintillation photon +400V +800V Photocathode The PMT • Serves two purposes: • Converts photonic signal to electronic signal • Amplifies electronic signal enough to be read
Construction process • Gluing in optical alignment • Wrapping with aluminum foil • Wrapping with dark plastic • Secure in mounting device • Make Light-tight
“Detecting” • How do we know we’re detecting radiation? • Hook up oscilloscope to output of PMT • Typical pulse
“Detecting” • Light leaks look different
Detecting Radiation from a source • Place a source in close proximity to scintillator • Charged particles work best (electron/positron emitters)
Detecting Cosmic Radiation • Not actually cosmic rays secondary muon emission from interaction in atmosphere • Easiest to detect • Most energetic • Least work involved!
Detecting Cosmic Radiation Both detectors give similar results at same input voltage
How to Measure Cosmic Ray Flux • Unable to complete due to lack of time and equipment • But…never the less: Ө2 Ө1 Ө1 > Ө2 PMT scintillator
Conclusion • MY DETECTORS WORK…….YAY!!! • Put `em together • Made `em light-tight • Detected both β particles (electrons) and μ particles (muons) • Now what?? GO TO TRIUMF…