Nitrogen-13

Properties and data of the isotope ¹³N.

Content

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

¹³N is a radioisotope of the element nitrogen with a half-life of just under 10 minutes. The atomic nucleus of the nulide is composed of 6 neutrons and the 7 element-specific protons.

The radionuclide occurs in the so-called Bethe-Weizsäcker cycle or CNO cycle (CNO for carbon, nitrogen, oxygen), one of the eight fusion reactions of the hydrogen burning of the sun or stars, in which hydrogen is converted into helium. Here, N-13 is an unstable intermediate product that decays after a short time, emitting a positron e⁺ and an electron neutrino ν_e:

¹²C + ¹H → ¹³N + γ + 1.95 MeV (reaction time: 1.3 × 10⁷ years),

¹³N → ¹³C + e⁺ + γ_e + 1.37 MeV (reaction time: 1.3 × 10^-5 years).

Nitrogen-13 is briefly formed in the earth's atmosphere during the nuclear reactions caused by lightning.

In medicine, ¹³N-labeled compounds (radiopharmaceuticals) are used for positron emission tomography (PET). Due to the short half-life, the corresponding substances are generated on site in a cyclotron:

¹H + ¹⁶O → ¹³N + ⁴He.< /p>

The proton ¹H must have a kinetic energy of 5.55 MeV or more. The nuclear reaction is endothermic - i.e. the mass of the products is greater than that of the reactants; therefore must Energy is supplied, which is converted into mass.

General data

Name of the isotope:Nitrogen-13; N-13Symbol:¹³N or 137NMass number A:13 (= number of nucleons)Atomic number Z:7 (= number of protons)Neutrons N:6Isotopic mass:13.00573861(29) u (atomic weight of Nitrogen-13)Nuclide mass:13.0018986 u (calculated nuclear mass without electrons)Mass excess:5.34548 MeVMass defect:0.10102611 u (per nucleus)Nuclear binding energy:94.10521531 MeV (per nucleus)
7.23886272 MeV (average binding energy per nucleon)Separation energy:S_N = 20.0639(10) MeV (first neutron)
S_P = 1.94349(27) MeV (first proton)Half-life:9.965(4) minDecay constant λ:0.0011593028609466 s^-1Specific activity α:5.370373175344 × 10⁺¹⁹ Bq g^-1
1451452209.5526 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2-Isobaric spin: 1/2Magnetic dipole moment:μ(μ_N) = 0.3219(4)Nuclear g-factor:g_l = 0.6438Mirror nucleus:Carbon-13Year of discovery:1934

Radioactive Decay

Mean β⁺ dose: 0.49085(12) MeV / Bq·s; Energy: 0.49182(12) MeV; Intensity 99.8036(20)%.

Half-life T_½ = 9.965(4) min (minutes) respectively 5.979 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β⁺	¹³C	100 %	2.22047(27) MeV

Parent Nuclides

Direct parent isotope is: ¹³O.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 6) and isobaric (same nucleon number A = 13) with Nitrogen-13. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 6	Isobar A = 13
1	⁷H
2	⁸He
3	⁹Li	¹³Li
4	¹⁰Be	¹³Be
5	¹¹B	¹³B
6	¹²C	¹³C
7	¹³N	¹³N
8	¹⁴O	¹³O
9	¹⁵F	¹³F
10	¹⁶Ne
11	¹⁷Na

External data and identifiers

CAS:13981-22-1Adopted Levels, Gammas:NuDat 13N

Literature and References

[1] - Teruaki Enoto et al.:
Photonuclear reactions triggered by lightning discharge.
In: Nature, (2017), DOI 10.1038/nature24630.

[2] - Vanessa Gómez-Vallejo, Luka Rejc, Fernando López-Gallego, Jordi Llop:
The Radiopharmaceutical Chemistry of Nitrogen-13 and Oxygen-15.
In: Radiopharmaceutical Chemistry, (2019), DOI 10.1007/978-3-319-98947-1_13.