'Standard atomic weights of the elements 2021 (IUPAC Technical Report)'. ^ Prohaska, Thomas Irrgeher, Johanna Benefield, Jacqueline et al.'The NUBASE2020 evaluation of nuclear properties' (PDF). Measurement of the gamma-ray spectrum provides information about the chemical state of the iron atom in the sample. Electron capture by 57Co forms an excited state of the 57Fe nucleus, which in turn decays to the ground state with the emission of a gamma ray. Density measurements (e.g., concrete density measurements)Ĭobalt-57 is used as a source in Mössbauer spectroscopy of iron-containing samples.Industrial radiography (e.g., weld integrity radiographs).Radiation treatment of foods for sterilization (cold pasteurization).Sterilization of medical supplies and medical waste.Industrial uses for radioactive isotopes Ĭobalt-60 ( 60Co) is useful as a gamma ray source because it can be produced in predictable quantities, and for its high radioactivity simply by exposing natural cobalt to neutrons in a reactor. The 60Co source is useful for about 5 years but even after this point is still very radioactive, and so cobalt machines have fallen from favor in the Western world where linacs are common. The metal has the unfortunate habit of producing fine dust, causing problems with radiation protection. The 60Co source is about 2 cm in diameter and as a result produces a geometric penumbra, making the edge of the radiation field fuzzy. It produces two gamma rays with energies of 1.17 MeV and 1.33 MeV. Ĭobalt-60 ( 60Co or Co-60) is used in radiotherapy. Use of cobalt radioisotopes in medicine Ĭobalt-57 ( 57Co or Co-57) is used in medical tests it is used as a radiolabel for vitamin B 12 uptake. ^ ( ) spin value – Indicates spin with weak assignment arguments.^ Bold symbol as daughter – Daughter product is stable.^ a b c # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).^ ( ) – Uncertainty (1 σ) is given in concise form in parentheses after the corresponding last digits.The main reaction is the (d,n) reaction 56Fe + 2H → n + 57Co. For example, 57Co is produced by cyclotron irradiation of iron. Radioactive isotopes can be produced by various nuclear reactions. The main decay products before 59Co are iron isotopes and the main products after are nickel isotopes. The main decay mode for isotopes with atomic mass less than that of the stable isotope, 59Co, is electron capture and the main mode of decay for those of greater than 59 atomic mass units is beta decay. The isotopes of cobalt range in atomic weight from 47Co to 75Co.

This element also has 11 meta states, all of which have half-lives of less than 15 minutes. All other isotopes have half-lives of less than 18 hours and most of these have half-lives of less than 1 second. Twenty-eight radioisotopes have been characterized the most stable are 60Co with a half-life of 5.2714 years, 57Co (271.8 days), 56Co (77.27 days), and 58Co (70.86 days). Naturally occurring cobalt ( 27Co) consists of a single stable isotope, 59Co.

Cobalt atomic