Editing Alpha decay (section)

== History == 
{{See also|Alpha particle#History of discovery and use}}
Alpha particles were first described in the investigations of radioactivity by [[Ernest Rutherford]] in 1899, and by 1907 they were identified as He<sup>2+</sup> ions.
By 1928, [[George Gamow]] had solved the theory of alpha decay via tunneling. The alpha particle is trapped inside the nucleus by an attractive nuclear [[potential well]] 
and a repulsive electromagnetic [[potential barrier]]. Classically, it is forbidden to escape, but according to the (then) newly discovered principles of [[quantum mechanics]], it has a tiny (but non-zero) probability of "[[quantum tunneling|tunneling]]" through the [[potential barrier|barrier]] and appearing on the other side to escape the nucleus. Gamow solved a model potential for the nucleus and derived, from first principles, a relationship between the [[half-life]] of the decay, and the energy of the emission, which had been previously discovered empirically and was known as the [[Geiger–Nuttall law]].<ref>{{cite web |url=http://www.phy.uct.ac.za/courses/phy300w/np/ch1/node38.html |title=Gamow theory of alpha decay |date=6 November 1996 |archive-url=https://web.archive.org/web/20090224200050/http://www.phy.uct.ac.za/courses/phy300w/np/ch1/node38.html |archive-date=24 February 2009}}</ref>