Americium (atomic number 95) is a synthetic element that is produced as a byproduct in certain nuclear reactions. It was first produced by Glenn Seaborg and his colleagues at the University of California, Berkeley. The isotope americium-241 now has commercial applications in the ionization chambers of smoke detectors. It decays by emission of alpha particles and has a half-life of 432.2 years.
In 1966, the statistician J. Berkson studied alpha particle emissions from a sample of americium-241. The table below is a frequency distribution for the number of emissions in 1207 ten-second intervals, and is adapted from data in Rice.
|Number of emissions||Frequency|
Click on the link below to download the data in tab-separated text format. This is a standard formats that can be imported into most statistical and spreadsheet software.