Aluminium-26

Aluminium-26 (26Al, Al-26) is a <a href="/facts/Radionuclide/5WpCfbdq">radioactive isotope</a> of the <a href="/facts/Chemical_element/0jducgWD">chemical element</a> <a href="/facts/Aluminium/7wmR8jYE">aluminium</a>, decaying by either <a href="/facts/Positron_emission/psWp4bJT">positron emission</a> or <a href="/facts/Electron_capture/EIccoV1u">electron capture</a> to stable <a href="/facts/Magnesium/XyIhd2FG">magnesium</a>-26. The <a href="/facts/Half-life/kGVH8BAB">half-life</a> of 26Al is 717,000 years. This is far too short for the isotope to survive as a <a href="/facts/Primordial_nuclide/lFAUqHDv">primordial nuclide</a>, but a small amount of it is produced by collisions of atoms with <a href="/facts/Cosmic_ray/uxCVdTKd">cosmic ray</a> <a href="/facts/Proton/clCjepXP">protons</a>.
Decay of aluminium-26 also produces <a href="/facts/Gamma_rays/5Drf913J">gamma rays</a> and <a href="/facts/X-rays/wseP79cN">x-rays</a>. The x-rays and <a href="/facts/Auger_effect/a0SVoK1r">Auger electrons</a> are emitted by the excited atomic shell of the daughter 26Mg after the electron capture which typically leaves a hole in one of the lower sub-shells.
Because it is radioactive, it is typically stored behind at least 5 centimetres (2 in) of lead. Contact with 26Al may result in radiological contamination. This necessitates special tools for transfer, use, and storage.

Aluminium-26 open-in-new

Aluminium-26