イレーヌ・ジョリオ＝キュリー
In 1934, Frédéric and Irène Joliot-Curie bombarded aluminium with alpha particles to effect the nuclear reaction  +  →  + , and observed that the product isotope emits a positron identical to those found in cosmic rays (discovered by Carl David Anderson in 1932). This was the first example of  decay (positron emission), which they termed artificial radioactivity since is a short-lived nuclide which does not exist in nature. In recognition of their discovery the couple were awarded the Nobel Prize in Chemistry in 1935.