Helium-6

Properties and data of the isotope ⁶He.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

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

General data

Name of the isotope:Helium-6; He-6Symbol:⁶He or 62HeMass number A:6 (= number of nucleons)Atomic number Z:2 (= number of protons)Neutrons N:4Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):2 (= neutron-proton ratio)Neutron excess (N-Z):2Isotopic mass:6.01888589(6) u (atomic weight of Helium-6)Nuclide mass:6.0177887 u (calculated nuclear mass without electrons)Mass excess:17.59209 MeVMass defect:0.031423838 u (per nucleus)Nuclear binding energy:29.27111655 MeV (per nucleus)
4.87851943 MeV (average binding energy per nucleon)Separation energy:S_N = 1.71(2) MeV (first neutron)
S_P = 22.59(9) MeV (first proton)Half-life:806.7(15) msDecay constant λ:0.85923785863387 s^-1Specific activity α:8.62408569480 × 10⁺²² Bq g^-1
2330833971569.2 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Isobaric spin: 1Charge radius:2.0660(111) femtometer fmMirror nucleus:Beryllium-6Year of discovery:1936

Radioactive Decay

Half-life T_½ = 806.7(15) ms respectively 8.067 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁶Li		3.50521(5) MeV

Parent Nuclides

Direct parent isotopes are: ⁷He, ¹¹Li.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 4) and isobaric (same nucleon number A = 6) with Helium-6. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 4	Isobar A = 6
1	⁵H	⁶H
2	⁶He	⁶He
3	⁷Li	⁶Li
4	⁸Be	⁶Be
5	⁹B	⁶B
6	¹⁰C
7	¹¹N
8	¹²O
9	¹³F

External data and identifiers

Adopted Levels, Gammas:NuDat 6He

Literature and References

[1] - C. Ji, Ch. Elster, D. R. Phillips:
⁶He nucleus in halo effective field theory.
In: Physical Review C, 90, 044004, (2014), DOI 10.1103/PhysRevC.90.044004.

[2] - Chrysovalantis Constantinou, Mark A. Caprio, James P. Vary, Pieter Maris:
Natural orbital description of the halo nucleus ⁶He and its halo structure.
In: Nuclear Science and Techniques, 28, 179, (2017), DOI 10.1007/s41365-017-0332-6.

[3] - Y.L. Sun, T. Nakamura, Y. Kondo et al.:
Three-body breakup of ⁶He and its halo structure.
In: Physics Letters B, 814, 136072, (2021), DOI 10.1016/j.physletb.2021.136072.