The Molybdenum-Technetium Generator (AQA A Level Physics) : Revision Note

The Molybdenum-Technetium Generator

• A molybdenum–technetium generator is a device that produces technetium from molybdenum

• Technetium-99m (Tc-99) has a half-life of 6.0 hours

  • This allows it to be used as a tracer with low irradiation of the patient, thanks to the short half-life

  • The short half-life, however, means it must be produced in the hospital when needed, as it cannot maintain the required levels of radioactivity for long periods of time

• Molybdenum-99 (Mo-99) has a half-life of 66 hours (2.8 days)

  • It is produced in nuclear reactors, and due to its slightly longer half-life, it can be transported to hospitals every week

• Once Mo-99 arrives at a hospital, it can be placed in a molybdenum-technetium generator to produce Tc-99m

• In the generator, Mo-99 decays over the course of a few days, producing Tc-99m for up to a week

  • Tc-99m is extracted from the generator every few days by passing a saline solution over the radioactive materials

  • Tc-99m enters the solution, which can then be extracted and injected into patients ready for scanning