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GENERAL: See 3 [Electromagnetic Transitions in A = 18-19] (in PDF or PS), 19.26 [General Table] (in PDF or PS), 19.27 [Table of Energy Levels] (in PDF or PS) and 19.28 [Radiative decays in ¹⁹Ne] (in PDF or PS).

1. 19Ne(β+)19F

Qm = 3.238

We adopt the half-life of ¹⁹Ne suggested by (1983AD03): 17.34 ± 0.09 s. See also (1978AJ03). The decay is principally to ¹⁹F_g.s.: see 19.29 (in PDF or PS). The ¹⁹Ne decay to ¹⁹F*(0.11) [J^π = 1/2⁺ → 1/2^-] proceeds by vector and axial vector weak currents, with the former making a negligible contribution. The measured decay rates are roughly an order of magnitude smaller than predicted using the 0ℏω + 1ℏω shell model (1981AD05, 1983AD03). Decay of polarized ¹⁹Ne is consistent with time-reversal invariance: see (1987AJ02, 1988SE11, 1993CA1K). See also (1988BR1D, 1988SA12, 1989SA55, 1991NA05, 1991SAZX, 1992HE12, 1992SE08, 1993SE1B).

2. 15O(α, γ)19Ne

Qm = 3.529

(1986LA07) have recalculated the ¹⁵O(α, γ) direct capture rate at stellar energies. (1990MA05) have measured the branching ratios Γ_α/Γ_total for E_cm = 850, 1020, 1071, 1183 and 1563 keV resonances in ¹⁵O + α. The strengths of these resonances were determined (see 19.30 (in PDF or PS)) and the reaction rate for temperatures between 7 × 10⁸ and 3 × 10⁹ K was determined to differ from theoretical calculations (1986LA07, 1988CA26) by no more than 20%. See also (1988BU01, 1988TR1C). A recent measurement by (1995MA28) determined Γ_α for E_x = 4033 keV and hence the resonant rate for ¹⁵O(α, γ) at astrophysical energies.

3. (a) 16O(3He, γ)19Ne	Qm = -3.196	Eb = 8.443
(b) 16O(3He, n)18Ne	Qm = -11.420
(c) 16O(3He, p)18F	Qm = 2.032
(d) 16O(3He, d)17F	Qm = -4.894
(e) 16O(3He, 3He')16O
(f) 16O(3He, α)15O	Qm = 4.914
(g) 16O(3He, 7Be)12C	Qm = -5.576

Excitation functions at 90° for γ_0-2, γ_3-5 and γ₆ [reaction (a)] have been measured for E(³He) = 3 to 19 MeV (1983WA05): see 19.31 (in PDF or PS) for a listing of the resonances reported in this and in the other channels. See also (1983AJ01, 1987AJ02) and (1990AB14, 1991SU17, 1992CO08).

4. 16O(α, n)19Ne

Qm = -12.134

Gamma transitions have been observed from the first six excited states of ¹⁹Ne: see 19.25 (in PDF or PS) in (1978AJ03) and 19.28 (in PDF or PS) here. Angular distributions of many neutron groups have been studied at E_α = 41 MeV: see (1983AJ01).

5. 16O(6Li, t)19Ne

Qm = -7.352

This reaction and the mirror reaction ¹⁶O(⁶Li, ³He)¹⁹Fhave been studied at E(⁶Li) = 24, 35, 36, and 46 MeV: see (1978AJ03, 1983AJ01). 19.16 (in PDF or PS) displays the analog states observed in the two reactions. In addition triton groups are reported to states with E_x = 6.08, 6.28, 6.85, 7.21, 8.08, 8.45, 8.94, 9.81, 10.01, 11.08, 11.24, 11.40, 12.56 [all ± 0.02], 13.1, 13.22, 14.18, 14.44, 14.78 [remaining, ± 0.3] MeV. See also (1983CU02) and the preliminary report in (1992ROZZ).

6. 16O(10B, 7Li)19Ne

Qm = -9.345

This as well as the analog reaction [¹⁶O(¹⁰B, ⁷Be)¹⁹F] have been studied at E(¹⁰B) = 100 MeV. On the basis of similar yields and E_x, and in addition to the low-lying analogs, it is suggested that the following pairs of states are analogs in ¹⁹F - (¹⁹Ne): 8.98 (8.94), 11.33 (11.09), 12.79 (12.48), 14.15 (14.17), 14.99 (14.61) and 15.54 (15.40) [ ± 100 keV]; however, problems of energy resolution are evident. See (1983AJ01) for references on this and on other heavy-ion induced reactions.

7. 16O(12C, 9Be)19Ne

Qm = -17.836

This ³He stripping reaction was studied at E(¹²C) = 480 MeV (1988KR11). The ground state, 0.2 MeV doublet and 1.5 MeV multiplet were weakly populated. High spin states at 2.8 MeV (9/2⁺) and 4.64 MeV (13/2⁺) were strongly populated and were inferred to belong to the (sd)³, 2N + L, g.s. band with ((1d_5/2)²2s_1/2)_9/2⁺ and (1d_5/2)³_13/2⁺ configurations. Levels at 8.9, 9.88 and 10.41 MeV were inferred to have spin parities of 11/2^-, 11/2⁺, and 13/2⁺. A 17/2^- spin parity was proposed for the strongly populated 12.3 MeV level.

8. 17O(3He, n)19Ne

Qm = 4.300

Neutron-γ coincidence measurements lead to the determination of excitation energies [E_x = 4032.9 ± 2.4, 4140 ± 4, 4197.1 ± 2.4, 4379.1 ± 2.2, 4549 ± 4, 4605 ± 5, 4635 ± 4 and (5097 ± 10) keV], τ_m and branching ratios (see 19.28 (in PDF or PS)). On the basis of these it is suggested that ¹⁹Ne*(4.14, 4.20) are the analogs of ¹⁹F*(4.03, 4.00) [J^π = 9/2^-, 7/2^-] and that ¹⁹Ne*(4.55, 4.60) are the analogs of ¹⁹F*(4.556, 4.550) J^π = 5/2⁺, 3/2^-]. There is no evidence for a reported state at E_x = 4.78 MeV: see (1978AJ03).

9. 18O(p, π-)19Ne

Qm = -134.812

This reaction (at E_p = 201 MeV) selectively populates stretched 2p-1h states, in particular ¹⁹Ne*(4.64) [J^π = 13/2⁺] and a structure near 10 MeV. Angular distributions and A_y are reported for ¹⁹Ne*(0, 2.80, 4.6) (1986KE04). See also (1987AJ02) and (1990KU1H).

10. 19F(p, n)19Ne

Qm = -4.020

For a review of threshold measurements see (1972AJ02, 1976FR13). Measurements of the total cross section from threshold (E_p = 4.24 MeV) to E_p = 28 MeV are reported by (1990WA10). Excited states of ¹⁹Ne determined from γ-spectra are displayed in 19.25 (in PDF or PS) of (1978AJ03). Branching ratio and τ_m measurements are summarized in 19.28 (in PDF or PS) here. For the g-factor of ¹⁹Ne*(0.24) see 19.27 (in PDF or PS). Angular distributions have been measured at E_p = 160 MeV to ¹⁹Ne*(0[0], 1.54[(0 + 2)], 5.4[0], 6.2[(0 + 1)], 7.1[(0 + 1)], 7.7[(0 + 1)], 8.60[(0)], 10.2[(1)], 11.0 [0], 12.1) (1984RA22; [transferred angular momentum in brackets] also forward-angle σ(θ) at E_p = 120 MeV). Spin-transfer coefficients were measured at E_p = 120, 160 MeV by (1990HUZY). See also ²⁰Ne in (1987AJ02) and (1987TA13, 1989RA1G).

11. 19F(3He, t)19Ne

Qm = -3.257

Angular distributions have been obtained for the triton groups to ¹⁹Ne*(0.24, 1.54, 2.79) at E(³He) = 26 MeV: see (1978AJ03). ¹⁹Ne levels at E_x = 7.060/7.088, 7.500, 7.531 and 7.620 MeV were measured to obtain Γ_p/Γ_α branching ratios (0.58 ± 0.08, 2.7 ± 0.9, 0.29 ± 0.09, and 0.34 ± 0.05, respectively) for determination of possible HCNO breakout reactions ¹⁸F(p, γ)¹⁹Ne and ¹⁸F(p, α)¹⁵O(α, γ)¹⁹Ne (1993UTZZ).

12. (a) 20Ne(n, 2n)19Ne	Qm = -16.864
(b) 20Ne → 19Ne + n

Theoretical calculations of neutron-induced reaction cross sections on ²⁰Ne in the energy range 1 - 30 MeV were performed (1991RE10). The shape and magnitude of the neutron yield from the breakup of ²⁰Ne [reaction (b)] was calculated in the high-energy region using diffraction theory of processes of fragmentation of complex nuclei.

13. 20Ne(3He, α)19Ne

Qm = 3.713

Alpha groups have been observed to ¹⁹Ne states with E_x < 10.6 MeV: see 19.27 (in PDF or PS) and 19.32 (in PDF or PS). Angular distributions have been measured for E(³He) = 10 to 35 MeV: see (1972AJ02). DWBA analysis of the strongest transitions leads to the l and J^π values shown in 19.32 (in PDF or PS). ¹⁹Ne*(0, 0.24, 1.54, 2.79) are identified as members of the K^π = 1/2⁺ rotational band [with ¹⁹Ne*(4.38) as the 7/2⁺ member] and ¹⁹Ne*(0.28, 1.51, 1.62) with the K^π = 1/2^- band. Candidates for the 7/2^- and 9/2^- members of the K^π = 1/2^- band are thought to be ¹⁹Ne*(4.15, 4.20). Possible matching of other ¹⁹Ne states with those in ¹⁹F is also discussed: see (1972AJ02). For lifetime and radiative decay measurements see 19.28 (in PDF or PS). See also (1987AJ02) and see (1989MC1C) for use of this reaction for observing parity-violating effects.

14. 21Ne(p, t)19Ne

Qm = 15.144

At E_p = 40 MeV the angular distributions to ¹⁹Ne*(0.24, 4.03, 5.09) are well described by L = 2, 0 and 4, respectively. ¹⁹Ne*(4.03), J^π = 3/2⁺, has a dominant 5p-2h configuration. ¹⁹Ne*(5.09) has positive parity and the data are consistent with J = 5/2. At E_p = 45 MeV the triton group to a state with E_x = 7.620 ± 0.025 MeV has an angular distribution [L = 0] which is similar to that for ¹⁹F*(7.66); both are thought to be the analogs of the (J^π; T) = (3/2⁺; 3/2) 0.096 MeV first excited state of ¹⁹O. The ground state of ¹⁹O has J^π = 5/2⁺; L for the analog state should be 2. ¹⁹Ne*(0, 2.79) are also populated: see (1978AJ03, 1983AJ01).