Sr-85 is produced by the spallation of molybdenum (natural Mo(p, spallation)85Sr). Its half-life is 65 days, and it disintegrates with electron capture and gamma radiation.

Sr-89 is produced in the 88Sr(n, Y)89Sr nuclear reaction. Its half-life is 50 days, в _-emitter.

Sr-90 is obtained as a fission product. Its half-life is 29 years, в — emitter. Its daughter nuclide is the 90Y isotope, which can be obtained from 90Sr/90Y-genera — tors and used for palliative therapy.

8.6.13 Yttrium-90

Y-90 is the daughter nuclide of Sr-90, so the production has been discussed at strontium isotopes. The industrial production will be shown in Section 8.7.1.1.

8.6.14 Technetium-99m (Tc-99m)

Tc-99m is the most frequently used radioisotope in nuclear medicine. In medical laboratories, Tc-99m is obtained from Mo-99/Tc-99m generators (see Eq. (8.8)). The parent nuclide, Mo-99, is produced as a fission product in the reprocessing of spent fuel elements. For more information, see Section 8.7.1.4.