Information on mass chains and nuclides

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GENERAL: See also (1966LA04) and Table 8.11 [Table of Energy Levels] (in PDF or PS).

Shell model: (1966BA26, 1973HA49).

Special levels: (1966BA26).

Electromagnetic transitions: (1966BA26, 1973HA49).

Special reactions: (1968BA1M, 1968BH1A, 1969BA1L, 1970BA44, 1972AG01).

Astrophysical questions: (1967BA1J, 1967SH1F, 1968BA2E, 1968BA2F, 1969FO1D, 1970BA1M, 1972PA1C).

Other topics: (1966KE16, 1966TO04, 1967DI1B, 1969GA1G, 1972AN05, 1973RO1R).

Ground-state properties: (1966BA26, 1972VA36, 1973HA77, 1973MA1K, 1973SU1B).

1. 8B(β+)8Be

Qm = 17.981

The β⁺ decay leads mainly to ⁸Be*(2.9). The half-life is 774 ± 5 msec (1964MA35), 762 ± 5 msec (1971WI05), 772 ± 4 msec (1973MCZW): the mean is 770 ± 3 msec. See also Table 8.19 (in PDF or PS) in (1966LA04): log ft = 5.64 ((1966BA1A) and B. Zimmerman, private communication). There is also a branch to a ⁸Be state at ≈ 16.6 MeV; log ft = 2.9 (1964MA35). See, however, (1969BA43): log ft = 3.33. Measurements of the excitation spectra in the decays of ⁸Li and ⁸B show no evidence for second-class currents: |g_IT| < 7 × 10^-4 (1971WI05). See also (1964FO1A, 1969BA1X, 1969BA1M, 1972BA2M, 1972KO1A, 1973BA2C) for astrophysical applications, (1967BA1M, 1970DA21, 1971LI1H, 1971WI1C, 1971WI18, 1972EM02, 1972HO23, 1972WI28, 1972WI1C, 1973EM1B, 1973HA49, 1973TO14, 1974WI1L; theor.).

2. 6Li(3He, n)8B

Qm = -1.975

At E(³He) = 3.5 to 5.7 MeV, time-of-flight spectra locate the first excited state at 0.767 ± 0.012 (1965FA03, 1966FA1A), 0.783 ± 0.010 MeV (1965MC06: Γ = 40 ± 10 keV). Angular distributions for the n₀ group have been reported at E(³He) = 4.8 to 5.7 MeV. The appearance of a forward peak indicates an L = 0 transfer and hence a knockout mechanism (L = 0 is forbidden for simple diproton stripping) (1967VA24). See also (1963DI02). A state at E_x = 2.17 ± 0.05 MeV is reported by (1963DI02; abstract). For threshold measurements see (1966LA04). See also ⁹B.

3. 7Be(p, γ)8B

Qm = 0.137

Absolute cross sections have been measured for E_p = 0.165 to 10.0 MeV (1969KA1K, 1972KA1B), 0.48 to 1.93 MeV (1966PA16) and 0.95 to 3.28 MeV (1970VA26). In the data of (1966PA16, 1972KA1B) a resonance at E_p = 724 keV reflects ⁸B*(0.77) with Γ_lab ≈ 46 keV: the peak cross section is 2.20 ± 0.22 μb, Γ_γ = 50 ± 25 meV. See also (1969KA1K).

The low-energy cross-section factor, evaluated at the Gamow peak (E_p ≈ 20 keV), S(0.02) = 0.031 keV · b (1973RO08). Other values are S(0) = 0.0335 ± 0.003 keV · b, dS/dE = -3 × 10^-5 b (1972KA1B), 0.035 ± 0.004 keV · b, dS/dE = -3 × 10^-5 b (1968PA1M) and 0.0430 ≤ S(0) ≤ 0.0453 keV · b (1970AU1B). See also (1969KA1K, 1970VA26). The relevance of this reaction to astrophysics is discussed by (1965TO02, 1966PA16, 1967FO1B, 1967TO1B, 1968BA1W, 1968BA2E, 1968PA1M, 1969BA1U, 1969BA1M, 1970AU1B, 1970VA26, 1971BA2X, 1972BA2M, 1972KA1B, 1972PA1C, 1972TO1D, 1973BA2C, 1973RO08, 1973TR1E).

4. 10B(p, t)8B

Qm = -18.531

At E_p = 49.5 MeV angular distributions have been measured for the tritons to ⁸B*(0, 2.32) (1970SQ01): L = 2 and L = 0 + 2, leading to J^π = 2⁺ and 3⁺, respectively. See also ¹⁰B(p, ³He)⁸Be. The energy of the excited state is 2.29 ± 0.05 MeV (1970SQ01), 2.34 ± 0.04 MeV (1968BR23): Γ_lab = 390 ± 40 keV (1967MC14). ⁸B*(0.78) is also observed. See also (1971KA04; theor.).

5. 11B(3He, 6He)8B

Qm = -16.920

At E(³He) = 50 MeV, ⁶He groups are observed to the first three states of ⁸B (1967MC14).

6. 12C(3He, 7Li)8B

Qm = -22.899

This reaction has been studied at E(³He) = 40.7 MeV (1971DE37).

7. 12C(α, 8Li)8B

Qm = -41.445

See (1968MC02).