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Angular correlation of gamma-rays

Project Title: Angular correlation of gamma-rays emitted by Sodium-22

Over the course of my Physics major I completed dozens of laboratory experiments. Towards the end of 2004, each final year student was required to perform an independent practical project in nuclear physics. I selected the problem of testing the prediction of nuclear theory that sodium-22 undergoes beta+ decay, which results in back-to-back gamma rays when the emitted positron annihilates an electron.

To test the prediction, I set up an experiment for measuring the time difference between gamma rays detected by two scintillators, from which I could calculate the frequency of simultaneous detections. I used trigonometry to predict the frequency of such events as a function of angle between the two detectors, and experimentally confirmed the predicted curve.

Graham Poulter,
8 Mar 2010, 13:13