Co-60

Cobalt-60

Technogenic

β, γ radiation

Half-life: 5,3 years
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Main emission lines: 1173keV, 1332keV

Where detected

Cobalt-60 is produced artificially by subjecting the only stable isotope cobalt-59 to neutron bombardment (in a nuclear reactor or using a neutron generator). It is found as a reference source from old radiometers, flaw detectors, gamma therapy apparatuses, or as a marker of man-made accidents and nuclear tests. Due to its high-energy gamma radiation, it is difficult to shield.

Co-57

Cobalt-57

Natural

β, γ radiation

Half-life: 271 days

Main emission lines: 14keV, 122keV, 136keV

Where detected

Cobalt-57 is a source of soft gamma radiation, has spectral lines of 14, 122 and 136 keV. Half-life 271.8 days, daughter isotope stable iron-57. It is obtained by proton irradiation of natural nickel-58 in a gas pedal.

Cobalt-57 is used to manufacture standards and sources for calibration of radiometric equipment and medical gamma-cameras. It is also applied in various studies as a radioactive tracer. Vitamin B 12 (albumin) labeled with Co-57 is used in diagnostic kits to study anemia.