132La

132La is a radioactive isotope of the element lanthanum (atomic number 57) with a mass number of 132. It is not found in nature and must be produced in nuclear reactions. In general, 132La lies far from the valley of stability, and its existence is of interest mainly to nuclear physicists studying the structure and decay of neutron-rich lanthanide nuclei.

Nuclear properties and decay characteristics: 132La has 57 protons and 75 neutrons. The isotope is short-lived, with lifetimes that vary by specific nuclear states and production method. The dominant decay mode for many neutron-rich lanthanide isotopes in this region is beta-minus decay, which would increase the atomic number to 58 and lead to a nucleus of cerium (132Ce) with gamma rays often accompanying the decay. Other decay paths, such as electron capture or beta-plus emission, are possible in principle depending on energy balance for a particular state, but beta-minus decay is typically favored for neutron-rich species near this mass.

Production and research use: 132La is produced in accelerator-based experiments through projectile fragmentation, spallation, or neutron irradiation of neighboring lanthanum or rare-earth nuclei. It appears in nuclear-reaction inventories and is studied to understand nuclear structure, decay schemes, and the synthesis of nearby isotopes. Due to its short half-life, it has no practical applications outside fundamental research.

Relation to other isotopes: Natural lanthanum is dominated by 139La, with a small fraction of 138La, both stable or long-lived compared with 132La. 132La is part of the broader set of lanthanum isotopes that inform models of nuclear stability and isotopic trends in the rare-earth region.

See also: isotopes of lanthanum, lanthanum.