Actinium-225

Actinium-225 (²²⁵Ac, Ac-225) is an isotope of actinium. It undergoes alpha decay to francium-221 with a half-life of 10 days, and is an intermediate decay product in the neptunium series (the decay chain starting at ²³⁷Np). Except for minuscule quantities arising from this decay chain in nature, ²²⁵Ac is entirely synthetic.

The decay properties of actinium-225 are favorable for usage in targeted alpha therapy (TAT); clinical trials have demonstrated the applicability of radiopharmaceuticals containing ²²⁵Ac to treat various types of cancer. However, the scarcity of this isotope resulting from its necessary synthesis in cyclotrons limits its potential applications.

Spectrum (Fullscreen)

30 minute measurement with a High Purity Germanium (HPGe) radiation detector.

Metadata

Isotope:	Actinium
Mass number:	225
Atomic number:	89
Neutron number:	136
…	…

Sources and Further Read

• https://en.wikipedia.org/wiki/Actinium-225