Information on mass chains and nuclides available on this website:

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GENERAL: See also (78AJ03) and Table 20.1 [Table of Energy Levels] (in PDF or PS).

Model calculations: (GR77H).

Special states: (GR77H).

Astrophysical questions: (WO78F).

Other topics: (GR77H, RA78K, BE79A).

1. 20O(β-)20F

Qm = 3.816

²⁰O decays to ²⁰F*(1.06) [J^π = 1⁺] with a half-life of 13.51 ± 0.05 sec (weighted mean of (MA70G, AL74K)), log ft = 3.75 ± 0.01. Upper limits for the branching to other states of ²⁰F are shown in Table 20.2 (in PDF or PS) of (78AJ03) and in Table IV of (AL74K). See also (KA81N; theor.).

2. 18O(t, p)20O

Qm = 3.079

Observed proton groups are displayed in Table 20.2 (in PDF or PS). The first excited state, ²⁰O*(1.67) has τ_m = 10.7 ± 0.4 psec (RU80) [M²|E2| = 1.76 ± 0.07 W.u.], 9.8 ± 0.7 psec (HE77E); g = -0.352 ± 0.015 [(RU80) and see (78AJ03)]. ²⁰O*(4.07) decays to ²⁰O*(0, 1.67) with branchings of 26 ± 4 and 74 ± 4%. The p - γ angular correlations lead to J = 2; the strength of the transition favors π = +[δ(E2/M1) = -0.18 ± 0.08 for the 2⁺ → 2⁺ transition]. ²⁰O*(4.46) and ²⁰O*(5.39) decay primarily via ²⁰O*(1.67); the direct ground-state decay is < 4% for the first and < 7% for the second of these states. The angular correlations are essentially isotropic, favoring J^π = 0⁺. The transition ²⁰O*(5.39 → 4.07) is not observed: the upper limit is 8% (YO81).

3. 18O(α, 2p)20O

Qm = -16.735

At E_α = 65 MeV the population of ²⁰O*(0, 1.67, 3.57) and of states at 7.78, 8.78 and 10.2 [± 0.1] MeV are reported (JA78I). See also (BI78K).

4. 18O(18O, 16O)20O

Qm = -0.628 (For other reactions leading to 20O see (78AJ03).)

Angular distributions have been measured to ²⁰O*(0, 1.67) at E(¹⁸O) = 24 to 36 MeV (KA77V) and to ²⁰O*(0, 1.67, 3.57, 4.07, 4.46) (KU79). A FRDWBA analysis shows L = 0 for the transitions to ²⁰O*(0, 4.46) but underestimates the absolute cross sections by an order of magnitude (KU79).