Cerium-119 is a radioisotope of the chemical element cerium, which has 61 neutrons in its atomic nucleus in addition to the element-specific 58 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 119. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ¹¹⁹Ce is exclusively for academic purposes.

For many years, cerium-119 was only recorded in theoretical model calculations and systematic reviews, without any experimental evidence. Neither ENSDF nor NUBASE listed the nuclide as observed until 2025, and previous isotope lists were limited to heavier cerium isotopes on the proton-poor side.

In 2025, cerium-119 was first experimentally identified. The isotope was produced by in-flight fragmentation of a uranium-238 beam with an energy of 345 MeV per nucleon at a beryllium target. Separation of the reaction products was carried out using the BigRIPS separator. The identification was based on an event-by-event analysis of particle momentum and time-of-flight data combined with energy loss measurements. At that time, no evidence of decay or spectroscopic investigations were available, so the half-life and nuclear spin states remain unknown [1].

The values ​​presented here are preliminary.

See also: list of Cerium isotopes.

General data

Radioactive Decay

Half-life T_½ = 200 ms respectively 2 × 10^-1 seconds s.

Isotones and Isobars

External data and identifiers

Literature and References

[1] - H. Suzuki, N. Fukuda, H. Takeda et al.:
Discovery of proton-rich radioactive isotopes in the Z = 60 region produced by the projectile fragmentation of a 345-MeV/nucleon ²³⁸U beam.
In: Progress of Theoretical and Experimental Physics, ptaf149, (2025), DOI 10.1093/ptep/ptaf149.

Last update: 2025-10-27

Perma link: https://www.chemlin.org/isotope/cerium-119

© 1996 - 2025 ChemLin