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18Ne (1983AJ01)
(See Energy Level Diagrams for 18Ne)
GENERAL: See also (1978AJ03) and Table 18.21 [Table of Energy Levels] (in PDF or PS).
Model calculations: (1979DA15, 1979SA31, 1980ZH01).
Electromagnetic transitions: (1977HA1Z, 1979SA31, 1982LA26).
Special states: (1977HE18, 1978KR1G, 1979DA15, 1979SA31, 1980OK01, 1982ZH1D).
Astrophysical questions: (1979WO07).
Complex reactions involving 18Ne: (1979HE1D).
Pion-induced capture and reactions (See also reaction 6.): (1977PE12, 1977SP1B, 1978BU09, 1978OS02, 1978SC1G, 1978SP07, 1979AL1J, 1979GR18, 1979SE08, 1980JO06, 1981LI04, 1981LI1L, 1981LI1M, 1981LI1W, 1981MI09, 1981OS1F, 1982IN1A).
Other topics: (1978KR1G, 1978SH1B, 1980ZH01, 1981SH17).
Ground state of 18Ne: (1977HA1Z, 1982ZH1D).
| 1. 18Ne(β+)18F | Qm = 4.447 |
The half-life of 18Ne is 1672 ± 5 msec: see (1978AJ03). The decay is primarily to 18F*(0, 1.04, 1.70) [Jπ = 1+, 0+, 1+; T = 0, 1, 0, respectively]. In addition there is an extremely weak branch (1.3 ± 0.3) × 10-3% to 18F*(1.08) [0-; 0] (1981AD01): see Table 18.19 (in PDF or PS) for the parameters of the decay. The (0+ → 0-) transition yields an upper limit of ±(0.5 ± 1.3) × 10-6 for the parity mixing in the 18F*(1.04, 1.08) 0+, 0- doublet (1981AD01). [See also the discussion in (1981HA06)]. See also (1980LO1B, 1981BOZY) and (1978SZ03, 1979WI1Q, 1980OK01, 1981HA1Q; theor.).
| 2. 16O(3He, n)18Ne | Qm = -3.196 |
Excitation energies of 18Ne states derived from neutron spectra and γ-ray measurements are displayed in Table 18.23 (in PDF or PS). Branching ratios and τm are summarized in Table 18.22 (in PDF or PS). For angular distributions see (1978AJ03) and (1981NE09). Comparison of the τm of 18Ne*(1.89), which leads to B(E2) = 52 ± 5 e2 · fm4, with that of 18O*(1.98), its analog, suggests the presence of two-body contributions to the E2 transition strength (1976MC02). See also (1977FI13; applications).
| 3. 16O(10B, 8Li)18Ne | Qm = -18.951 |
At E(10B) = 100 MeV the angular distribution to 18Ne*(3.38) [(d5/2)24+ state] which is preferentially populated, has been studied by (1978HA10): 18Ne*(1.89) is also observed.
| 4. 16O(11B, 9Li)18Ne | Qm = -26.344 |
At E(11B) = 115 MeV 18Ne*(3.38) [Jπ = 4+] is selectively populated (1979RA10).
| 5. 16O(12C, 10Be)18Ne | Qm = -22.664 |
See (1978AJ03).
| 6. 18O(π+, π-)18Ne | Qm = -6.101 |
Angular distributions of the transition to 18Neg.s. have been studied at Eπ+ = 164 MeV (1979GR18, 1979SE08, 1982GR1F; also to 18Ne*(1.89)), and at 292 MeV (1982GR1F). The excitation function for production of 18Ne*(0, 1.89) have been measured by (1979GR18, 1982GR02, 1982GR1F) for Eπ+ = 80 to 292 MeV. See also (1978AJ03), (1977PE12, 1978BU09, 1982GRZZ) and the "GENERAL" section here.
| 7. 20Ne(p, t)18Ne | Qm = -20.023 |
Observed triton groups are displayed in Table 18.23 (in PDF or PS) as are Jπ derived from DWBA analysis of angular distributions. The 0+3 state, identified at Ex = 4.59 MeV, appears to have a largely s21/2 configuration based on its large downward shift with respect to the analog state in 18O (1981NE09). See also (1978AJ03).