Study suggests germanium isotope really does have an 11-day half-life
Searching for the elusive neutrino takes on many forms. Detectors consisting of many tons of gallium are used in several experiments because neutrino interactions can occur on the stable gallium-71 (71Ga) nucleus and transform it into a radioactive isotope of germanium (71Ge) with an 11-day half-life that can then be observed with traditional radiation detectors.
Source: phys.org
