The Half Life of Radon 222 and Polonium 218

PAC

Gamow’s model of alpha decay predicts a linear relationship between the logarithm of the observed half-life of alpha emitters and the reciprocal of the square root of the kinetic energy released in the alpha decay. The relationship between the mean lives of alpha-active nuclides and the energies of the alpha particles they emit can be observed by measuring the half-lives of elements like Rn222 and Po218 which have half-lives in timescales of days and minutes. We constructed an alpha particle spectrometer to measure the 3.8 day half life of Rn-222, and constructed a timer/controller circuit to improve the data collection for the three minute half life of Po-218. Since these isotopes have such short half lives, they are not available commercially; however, we safely extracted them from Uranium ore placed in a high electric potential. The Radon was captured in charcoal placed next to the ore. Finally, we developed a Matlab program to determine the decay timescale with a three-parameter model.