57Co

Cobalt-57 (57Co) is a radioactive isotope of cobalt with a mass number of 57. It has a half-life of about 271.8 days and decays by electron capture to stable iron-57 (57Fe). Through this decay, 57Co emits characteristic gamma rays that are useful in a variety of laboratory applications.

The principal gamma emissions from 57Co are photons with energies around 122 keV and 14.4 keV. The 122 keV line is widely used for energy calibration of gamma-ray detectors and cameras, including gamma spectrometers and diagnostic imaging equipment. The 14.4 keV gamma line arises from the iron-57 nucleus formed in the decay and is the signature used in iron-57 Mössbauer spectroscopy, a technique employed to study the electronic and magnetic environment of iron in materials.

Production and handling: 57Co is produced in nuclear reactors or particle accelerators by irradiating suitable target materials, followed by chemical separation to isolate the cobalt-57 isotope. Because it is a sealed gamma source, 57Co is typically manufactured and used in a form that minimizes dispersion of radioactive material, with safety and regulatory controls governing its handling and disposal.

Applications: In research and industry, 57Co serves as a standard calibration source for gamma-ray instrumentation due to its stable, well-defined gamma emissions. Its 14.4 keV line enables Mössbauer spectroscopy studies of iron-containing compounds, contributing to fields such as materials science, geology, and chemistry.

Safety: As a radioactive sealed source, 57Co requires appropriate radiation protection, regulatory compliance, and proper storage and disposal to minimize exposure to personnel and the environment.