Manganese55

Manganese-55 (denoted as ⁵⁵Mn) is a radioactive isotope of manganese with a half-life of approximately 3.7 million years. It is a naturally occurring isotope, though it is present in trace amounts compared to the stable manganese-55 isotope, which is the only stable isotope of manganese. Manganese-55 is primarily produced through cosmic ray interactions with atmospheric nitrogen and argon, contributing to the natural background radiation on Earth.

This isotope undergoes beta decay, transforming into chromium-55 (⁵⁵Cr) with a maximum beta particle energy of 2.84 MeV. The decay process also emits gamma radiation, though it is relatively weak compared to other isotopes. Due to its long half-life, manganese-55 does not pose an immediate health risk, but prolonged exposure to its radiation could theoretically contribute to cumulative radiation dose over extended periods.

Manganese-55 is not commonly used in medical or industrial applications due to its low radioactivity and long half-life. However, it has been studied in the context of cosmic ray research and nuclear astrophysics, where it serves as a tracer for understanding stellar nucleosynthesis and the propagation of cosmic rays in the atmosphere. Its presence in the environment is generally negligible, and it does not significantly impact human health or the ecosystem.

In nuclear physics, manganese-55 is occasionally referenced in discussions about primordial radionuclides—radioactive isotopes that have existed since the formation of the solar system. Its slow decay rate makes it a useful marker for studying long-term geological and cosmic processes. Overall, manganese-55 remains a minor but interesting isotope in the broader study of nuclear science and radiation.