Carrier-free 54Mn can be produced from the natural isotopes of the iron 56Fe (d, a)54Mn and 54Fe(n, p)54Mn nuclear reactions. In carrier-added form, it can be produced from natural manganese by the 55Mn(n,2n)54Mn nuclear reaction. Manganese is one of the rare elements that consists of only one isotope—in this case 55Mn. The half-life of 54Mn is 312 days, and it disintegrates by electron cap­ture and gamma radiation.

8.6.7 Iron Isotopes

Fe-52 is produced by the spallation of nickel-58 with protons (58Ni(p, spallation)52Fe); its half-life is 8.3 h, it is a positron emitter nuclide, but its daugh­ter nuclide, the metastable Mn-52m, has a shorter half-life, so an Fe-52-Mn-52m generator can be prepared.

Fe-55 is produced from iron by the 54Fe(n, Y)55Fe nuclear reaction. Carrier-free Fe-55 isotopes is produced from manganese by the 55Mn(d, p)55Fe reaction. half­life is 2.7 years, and it decays by electron capture.

Fe-59 forms from the subsequent (n, Y) nuclear reaction of stable iron isotopes, half-life is 44.5 days, and it emits (3_ and gamma radiation.

8.6.8 Cobalt-60

It can be produced from the stable isotope of cobalt in the 59Co(n, Y)60Co nuclear reaction, and its half-life is 5.5 years. It has two gamma lines at 1178 and 1333 keV. Co-60 is applied in sterilizing and therapeutic irradiations. For additional information, see Section 8.8.