Cerium-151

Properties and data of the isotope ¹⁵¹Ce.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Cerium-151 is a radioisotope of the chemical element cerium, which has 93 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 151. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ¹⁵¹Ce is exclusively for academic purposes.

According to a report from 1997 [1], excited states of the nuclide cerium-151 were experimentally detected for the first time. The neutron-rich isotope originated as a fission fragment of a curium-248 source, whose spontaneous fission promptly produced emitted γ-quanta. These were recorded in coincidence with a highly sensitive detector array and analyzed mass-selectively, allowing transitions in the level scheme to be clearly identified. However, the observation was not considered the discovery of a new isotope, since a lifetime measurement had already been carried out in 1969 as part of a dissertation [J. B. Wilhelmy, Thesis, Univ. California, Berkeley, Lawrence Radiation Lab (1969); UCRL-18978 (1969)], which had first detected ¹⁵¹Ce. The early identification was based on the analysis of the decay behavior and characteristic γ-radiation, without excited states being described at that time.

See also: List of individual Cerium isotopes (and general data sources).

General data

Name of the isotope:Cerium-151; Ce-151Symbol:¹⁵¹Ce or 15158CeMass number A:151 (= number of nucleons)Atomic number Z:58 (= number of protons)Neutrons N:93Isotopic mass:150.934272(19) u (atomic weight of Cerium-151)Nuclide mass:150.9024566 u (calculated nuclear mass without electrons)Mass excess:-61.22524 MeVMass defect:1.325417044 u (per nucleus)Nuclear binding energy:1234.61802398 MeV (per nucleus)
8.1762783 MeV (average binding energy per nucleon)Separation energy:S_N = 4.450(21) MeV (first neutron)
S_P = 12.203(18) MeV (first proton)Half-life:1.76(6) sDecay constant λ:0.39383362531815 s^-1Specific activity α:1.581147711363 × 10⁺²¹ Bq g^-1
42733721928.746 Ci g^-1Spin and parity:
(nuclear angular momentum)(3/2-)Year of discovery:1997

Radioactive Decay

Half-life T_½ = 1.76(6) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁵¹Pr	100 %	5.555(21) MeV

Parent Nuclides

Direct parent isotope is: ¹⁵¹La.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 93) and isobaric (same nucleon number A = 151) with Cerium-151. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 93	Isobar A = 151
54	¹⁴⁷Xe
55	¹⁴⁸Cs	¹⁵¹Cs
56	¹⁴⁹Ba	¹⁵¹Ba
57	¹⁵⁰La	¹⁵¹La
58	¹⁵¹Ce	¹⁵¹Ce
59	¹⁵²Pr	¹⁵¹Pr
60	¹⁵³Nd	¹⁵¹Nd
61	¹⁵⁴Pm	¹⁵¹Pm
62	¹⁵⁵Sm	¹⁵¹Sm
63	¹⁵⁶Eu	¹⁵¹Eu
64	¹⁵⁷Gd	¹⁵¹Gd
65	¹⁵⁸Tb	¹⁵¹Tb
66	¹⁵⁹Dy	¹⁵¹Dy
67	¹⁶⁰Ho	¹⁵¹Ho
68	¹⁶¹Er	¹⁵¹Er
69	¹⁶²Tm	¹⁵¹Tm
70	¹⁶³Yb	¹⁵¹Yb
71	¹⁶⁴Lu	¹⁵¹Lu
72	¹⁶⁵Hf
73	¹⁶⁶Ta
74	¹⁶⁷W
75	¹⁶⁸Re
76	¹⁶⁹Os
77	¹⁷⁰Ir
78	¹⁷¹Pt
79	¹⁷²Au
80	¹⁷³Hg

Data changes (history)

Spin/Parity: Two different assignments for the ground state of Cer-151 can be found in the literature, namely (5/2⁺) and (3/2⁻). The value Jⁿ = (3/2⁻) is listed as the adopted ground state of ¹⁵¹Ce in the current NUBASE and ENSDF evaluations and is based on β-decay studies that support this assignment. Previous alternatives such as (5/2⁺) have not been confirmed in recent compilations.

External data and identifiers

Adopted Levels, Gammas:NuDat 151Ce

Literature and References

[1] - F. Hoellinger, N. Schulz, J. L. Durell et al.:
Spectroscopy of neutron-rich odd-A Ce isotope.
In: Physical Review C, 56, 1296, (1997), DOI 10.1103/PhysRevC.56.1296.