Carbon-9

Properties and data of the isotope ⁹C.

Contents

Carbon-9 is a radioisotope of the chemical element carbon, which, in addition to the element-specific 6 protons, has 3 neutrons in the atomic nucleus, resulting in the mass number 9. The very short-lived, unstable and therefore radioactive nuclide, which can only be produced artificially, currently has no practical significance; Among other things, potential use as a medical radionuclide for cancer therapy was discussed [3].

The discovery of the proton-rich isotope was reported in 1964: The detection was achieved by irradiating a carbon-12 target in a cyclotoron with a beam of helium-3 nuclei accelerated to 65 MeV [1]:

¹²C(³He,⁶He)⁹C.

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

General data

Name of the isotope:Carbon-9; C-9Symbol:⁹C or 96CMass number A:9 (= number of nucleons)Atomic number Z:6 (= number of protons)Neutrons N:3Isotopic mass:9.0310372(23) u (atomic weight of Carbon-9)Nuclide mass:9.0277457 u (calculated nuclear mass without electrons)Mass excess:28.91097 MeVMass defect:0.041907739999999 u (per nucleus)Nuclear binding energy:39.03680836 MeV (per nucleus)
4.33742315 MeV (average binding energy per nucleon)Separation energy:S_N = 14.225(18) MeV (first neutron)
S_P = 1.2996(24) MeV (first proton)Half-life:126.5(9) msDecay constant λ:5.4794243522525 s^-1Specific activity α:3.666429475625 × 10⁺²³ Bq g^-1
9909268853042.7 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2-Isobaric spin: 3/2Magnetic dipole moment:μ(μ_N) = -1.3914(5)Nuclear g-factor:g_l = -0.9276Charge radius:2.984 femtometer fmMatter radius:2.664 femtometer fmMirror nucleus:Lithium-9Year of discovery:1964

Radioactive Decay

Half-life T_½ = 126.5(9) ms respectively 1.265 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy
EC/β⁺	⁹B		16.4948(23) MeV
β⁺, p	⁸Be	62.0(19) %	16.6803(25) MeV
β⁺, α	⁵Li	37.9(58) %	14,807(50) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 3) and isobaric (same nucleon number A = 9) with Carbon-9. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 3	Isobar A = 9
1	⁴H
2	⁵He	⁹He
3	⁶Li	⁹Li
4	⁷Be	⁹Be
5	⁸B	⁹B
6	⁹C	⁹C
7	¹⁰N	⁹N
8	¹¹O

External data and identifiers

Adopted Levels, Gammas:NuDat 9C

Literature and References

[1] - Joseph Cerny et al.:
Completion of the Mass-9 Isobaric Quartet via the Three-Neutron Pickup Reaction C¹²(He³,He⁶)C⁹.
In: Physical Review Letters, 13, 726, (1964), DOI 10.1103/PhysRevLett.13.726.

[2] - U. C. Bergmann et al.:
On the β-decay of ⁹C.
In: Nuclear Physics A, 692, 3-4, 427, (2001), DOI 10.1016/S0375-9474(01)00650-9.

[3] - Qiang Li, Tatsuaki Kanai, Atsushi Kitagawa:
The potential application of β-delayed particle decay beam ⁹C in cancer therapy.
In: Physics in Medicine & Biology, 49, 1817, (2004), DOI 10.1088/0031-9155/49/9/016.