254Es

254Es, or Einsteinium-254, is a radioactive isotope of the transuranic element einsteinium (atomic number 99) with a mass number of 254. It is a synthetic isotope not found in nature. 254Es is produced in specialized facilities, such as nuclear reactors or particle accelerators, by neutron irradiation of heavier actinides followed by beta decays or by heavy-ion reactions, and is isolated by chemical separation.

The primary decay mode of 254Es is alpha decay to berkelium-250 (Bk-250). This makes the isotope highly radioactive and short-lived relative to many lighter elements. Some experiments indicate a small spontaneous fission branch may occur, but alpha decay is the dominant pathway. As with other heavy actinides, 254Es decays into heavier elements and ultimately contributes to the production chain of transuranic isotopes.

In laboratory research, 254Es is used to study actinide chemistry and nuclear structure, and to provide data for models of heavy-element production and decay. It has no practical commercial applications due to its scarcity, radioactivity, and short availability. Safety and containment considerations are significant when handling, producing, or studying 254Es.

See also: Einsteinium isotopes, Isotopes of einsteinium, Transuranium elements, Alpha decay.