Advanced Physics Laboratories

Gamma rays are MeV photons. They are typically emitted in the  electronic transitions radioactive nuclei, and carry information on nuclear binding and energy levels. They are recently of increased astrophysical interest, as "gamma-ray bursters" seem to be telling us something about the mechanics of stellar collapse. In this experiment, you will establish the function of a NaI crystal + photomultiplier system to detect gamma-rays, and use the system to study some interesting nuceli. Co-60, used for medical radiation treatment, is a standard gamma ray reference source. Na-22 undergoes beta decay to positrons, and you can see the gammas rays that result when they annihilate with electrons. The  gamma ray energy spectra also contain information about how gamma rays interact with matter.