Chapter 31 Virtual Lab

Radioactive Half Life of Barium 137; Absorption of Nuclear Radiation

Uses: Radioactive Half life, Geiger counter, decay schemes, isomers, absorption of radiation

A Cesium-137/Barium-137m generator is used to produce a short half-life source of radiation for investigation of radioactive decay. Cesium-137, with a half-life of 30 years, beta decays to produce Barium-137m which is an isomeric state of the stable Barium-137. Barium-137m decays with a short half-life into the stable Bariuim-137 by gamma decay.

Barium-137m is separated from the stable Cesium-137 by washing with a minigenerator. The short half-life of Barium-137m can then be investigated by repeated measure of its activity over time.

The same apparatus is used to investigate the absorption of radiation through various thicknesses of aluminum.