Carbon-15

Properties and data of the isotope ¹⁵C.

Contents

Carbon-15 is a radioisotope of the chemical element carbon, which has 9 neutrons in its atomic nucleus in addition to the element-specific 6 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 15. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ¹⁵C is exclusively for academic purposes.

The discovery of the radioactive isotope was reported in 1950; according to it, ¹⁵C was produced by bombarding a target made of barium carbonate - the carbon content of which was 40% enriched with carbon-14 - with deuterons (hydrogen-2 nuclei) accelerated to 2.4 MeV [1]:

¹⁴C(d,p)¹⁵C.

Another method for producing the nuclide is the following nuclear reaction [2]:

¹⁸O(n,α)¹⁵C.

General data

Name of the isotope:Carbon-15; C-15Symbol:¹⁵C or 156CMass number A:15 (= number of nucleons)Atomic number Z:6 (= number of protons)Neutrons N:9Isotopic mass:15.0105993(9) u (atomic weight of Carbon-15)Nuclide mass:15.0073078 u (calculated nuclear mass without electrons)Mass excess:9.87318 MeVMass defect:0.114335136 u (per nucleus)Nuclear binding energy:106.50249317 MeV (per nucleus)
7.10016621 MeV (average binding energy per nucleon)Separation energy:S_N = 1.2181(8) MeV (first neutron)
S_P = 21.080(21) MeV (first proton)Half-life:2.449(5) sDecay constant λ:0.28303274012248 s^-1Specific activity α:1.136308685994 × 10⁺²² Bq g^-1
307110455674.14 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2+Isobaric spin: 3/2Magnetic dipole moment:μ(μ_N) = 1.720(9)Nuclear g-factor:g_l = 3.44Charge radius:2.576 femtometer fmMatter radius:2.755 femtometer fmMirror nucleus:Fluorine-15Year of discovery:1950

Radioactive Decay

Half-life T_½ = 2.449(5) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁵N	100 %	9.7717(8) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 9) and isobaric (same nucleon number A = 15) with Carbon-15. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 9	Isobar A = 15
3	¹²Li
4	¹³Be	¹⁵Be
5	¹⁴B	¹⁵B
6	¹⁵C	¹⁵C
7	¹⁶N	¹⁵N
8	¹⁷O	¹⁵O
9	¹⁸F	¹⁵F
10	¹⁹Ne	¹⁵Ne
11	²⁰Na
12	²¹Mg
13	²²Al
14	²³Si
15	²⁴P

External data and identifiers

Adopted Levels, Gammas:NuDat 15C

Literature and References

[1] - Emmett L. Hudspeth, Charles P. Swann, N. P. Heydenburg:
Production of C¹⁵.
In: Physical Review, 77, 736, (1950), DOI 10.1103/PhysRev.77.736.

[2] - T. Malkiewicz et al.:
Production of a ¹⁵C radioactive ion beam based on ¹⁸O(n,α).
In: The European Physical Journal A, 55, 88, (2019), DOI 10.1140/epja/i2019-12761-y.

[3] - L. Moschini, J. Yang, P. Capel:
From Halo Effective Field Theory to the study of breakup and transfer reactions: reliably probing the halo structure of ¹¹Be and ^15C.
In: Journal of Physics: Conference Series, 1610, 012010, (2020), DOI 10.1088/1742-6596/1610/1/012010.