(See Energy Level Diagrams for 19Ne)
μ0.239 = -0.740 (8) nm (1978LEZA)
We adopt the half-life of 19Ne suggested by (1983AD03): 17.34 ± 0.09 sec. See also (1978AJ03). The decay is principally to 19Fg.s.: see Table 19.23 (in PDF or PS). The 19Ne decay to 19F*(0.11) [Jπ = 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 0 ℏω + 1 ℏω shell model (1981AD05, 1983AD03). The decay of polarized 19Ne is consistent with time-reversal invariance: see (1983SC32, 1984HA01). See also (1983AD1C, 1983AD1B, 1983AD1D, 1983VA01, 1984AD1E, 1984SI1G, 1985AD1A, 1985CA1P, 1985GR1A, 1986WI1P) and (1983CA03 [see for discussion of weak magnetism form factor and for search for heavy neutrinos], 1983GI1B, 1983VO05, 1984BO03, 1984HO1L, 1985GI09, 1986BR1X; theor.).
Excitation functions at 90° for γ0-2, γ3-5 and γ6 [reaction (a)] have been measured for E(3He) = 3 to 19 MeV (1983WA05): see Table 19.24 (in PDF or PS) for a listing of the resonances reported in this and in other channels. See also (1983AJ01) and (1981LE01, 1985HA11, 1986BA89, 1987CO07; theor.).
Gamma transitions have been observed from the first six excited states of 19Ne: see Table 19.25 (in PDF or PS) in (1978AJ03) and Table 19.21 (in PDF or PS) here. Angular distributions of many neutron groups have been studied at Eα = 41 MeV: see (1983AJ01).
This reaction and the mirror reaction 16O(6Li, 3He)19F have been studied at E(6Li) = 24, 35, 36 and 46 MeV: see (1978AJ03, 1983AJ01). Table 19.13 (in PDF or PS) displays the analog states observed in the two reactions. In addition triton groups are reported to states with Ex = 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, ± 0.03] MeV. See also (1983CU02).
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 Ex, 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.
Neutron-γ coincidence measurements lead to the determination of excitation energies [Ex = 4032.9 ± 2.4, 4140 ± 4, 4197.1 ± 2.4, 4379.1 ± 2.2, 4549 ± 4, 4605 ± 5, 4635 ± 4 and (5097 ± 10) keV], τm and branching ratios (see Table 19.21 (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) [Jπ = 9/2-, 7/2-] and that 19Ne*(4.55, 4.60) are the analogs of 19F*(4.556, 4.550) [Jπ = 5/2+, 3/2-]. There is no evidence for a reported state at Ex = 4.78 MeV: see (1978AJ03).
This reaction (at Epol. p = 201 MeV) selectively populates stretched 2p-1h states, in particular 19Ne*(4.64) [Jπ = 13/2+] and a structure near 10 MeV. Angular distributions and Ay are reported for 19Ne*(0, 2.80, 4.6) (1986KE04). See also (1982VI05), (1986JA1H) and (1984BEZZ; theor.).
Neutron measurements are shown in Table 19.24 (in PDF or PS) of (1972AJ02). Excited states of 19Ne determined from γ-spectra are displayed in Table 19.25 (in PDF or PS) of (1978AJ03). Branching ratio and τm measurements are summarized in Table 19.22 (in PDF or PS) here. For the g-factor of 19Ne*(0.24) see Table 19.21 (in PDF or PS). Recently angular distributions have been measured at Ep = 160 MeV to 19Ne*(0, 1.54[(0 + 2)], 5.4, 6.2[(0 + 1)], 7.1[(0 + 1)], 7.7[(0 + 1)], 8.60[(0)], 10.2[(1)], 11.0, 12.1) (1984RA22; [L in brackets] also forward σ(θ) at Ep = 120 MeV). See (1984RA22, 1985WA24) for discussions of the GT strengths. See also 20Ne, (1983RA1C, 1984TAZS) and (1985BA66; applications).
Angular distributions have been obtained for the triton groups to 19Ne*(0.24, 1.54, 2.79) at E(3He) = 26 MeV: see (1978AJ03).
Alpha groups have been observed to 19Ne states with Ex < 10.6 MeV: see Tables 19.21 (in PDF or PS) and 19.25 (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 Jπ values shown in Table 19.25 (in PDF or PS). 19Ne*(0, 0.24, 1.54, 2.79) are identified as members of the K = 1/2+ rotational band [with 19Ne*(4.38) as the 7/2+ member] and 19Ne*(0.28, 1.51, 1.62) with the Kπ = 1/2- band. Candidates for the 7/2- and 9/2- members of the K = 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 Table 19.21 (in PDF or PS). See also (1981CL05; theor.).
At Ep = 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), Jπ = 3/2+, has a dominant 5p-2h configuration. 19Ne*(5.09) has π = + and its J is consistent with 5/2. At Ep = 45 MeV the triton group to a state with Ex = 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 (Jπ; T) = (3/2+; 3/2) 0.096 MeV first excited state of 19O. The ground state of 19O has Jπ = 5/2+; L for the anaolg state should be 2. 19Ne*(0, 2.79) are also populated: see (1978AJ03, 1983AJ01).