Cobalt-60 (60Co) is a radioactive isotope of cobalt, with a half life of 5.27 years. 60Co decays by negative beta decay to the stable isotope nickel-60 (60Ni). In the process of decay, 60Co emits one electron with an energy of up to 315 keV and then two gamma rays with energies of 1.17 and 1.33 MeV, respectively.
One gram of 60Co contains approximately 50 curies (1.85 terabecquerels) of radioactivity. With a point source at a range of 1 m, this amount of 60Co would give a person a radiation dose of 0.5 sievert (50 rem) per hour. 60Co has seven main beneficial uses:
The creation of 60Co is an important step in nucleosynthesis. Without the 60Co step, no elements from number 27 through 83 would be created in supernovas. Artificial 60Co is created by bombarding a 59Co target with a slow neutron source, usually 252Cf moderated through water to slow the neutrons down, or in a nuclear reactor such as CANDU, where adjuster rods usually made of steel are instead made of Co-59. 60Co is also the active isotope in a so-called cobalt bomb, a theoretically feasible but extremely "dirty" form of nuclear weapon whereby a tamper of 59Co is irradiated by neutron radiation from the fission process and transmuted to 60Co.
LHSC celebrates the 60th anniversary of the world's first cancer treatment with Cobalt-60 radiation.(London Health Sciences Centre)
Nov 08, 2011; On October 27, 1951, the world's first cancer treatment with Cobalt-60 radiation took place at Victoria Hospital. This...