
^{19}O (1995TI07)(See Energy Level Diagrams for ^{19}O) GENERAL: See 3 [Electromagnetic Transitions in A = 1819] (in PDF or PS), 19.1 [General Table] (in PDF or PS), 19.2 [Table of Energy Levels] (in PDF or PS) and 19.3 [Radiative decays in ^{19}Ne] (in PDF or PS).
The weighted mean of several halflives is 26.96 ± 0.07 s: see (1972AJ02, 1987AJ02). The decay is complex: see reaction 34 of ^{19}F and 19.23 (in PDF or PS) and 19.24 (in PDF or PS).
See (1983AJ01).
States of ^{19}O reported in this reaction are displayed in 19.4 (in PDF or PS).
Proton groups corresponding to ^{19}O states with E_{x} ≤ 5.6 MeV and E_{γ} measurements are displayed in 19.5 (in PDF or PS).
The thermal capture cross section is 0.16 ± 0.01 mb (1981MUZQ). The scattering length b = 5.84 ± 0.07 fm, σ_{free} = 3.86 ± 0.10 b (1979KO26). The total cross section has been measured for E_{n} = 0.14 to 2.47 MeV [see (1978AJ03)] and at E_{n} = 5 to 7.5 MeV [G. Auchampaugh, quoted in (1986KO10)]. A multilevel Rmatrix analysis of these and additional σ(θ) data leads to the states shown in 19.6 (in PDF or PS) and to some additional structures. The five 7/2^{} states [^{19}O*(6.27, 9.64, 9.84, 10.21, 10.66)] (see, however, footnote (a) to 19.6 (in PDF or PS)) contain about 20  30% of the allowed f_{7/2} singleparticle strength. See also the compilation of neutron cross sections in (1988MCZT). Isobaric analog assignments are presented (1986KO10). See also (1982RA1A) and see the astrophysical discussion in (1988AP1A, 1988MA1U).
The total cross sections for the α_{0} and α_{1} groups have been measured for E_{n} = 7.5 to 8.6 MeV: resonance structure is reported at E_{n} = 7.70 ± 0.05 and 8.05 ± 0.05 MeV with Γ_{lab} = 0.25 and 0.35 MeV, respectively [^{19}O*(11.25, 11.58)]: see (1978AJ03).
Angular distributions have been measured at E_{d} = 0.8 to 15 MeV: see (1978AJ03, 1983AJ01). The l_{n} values and spectroscopic factors derived from these measurements are displayed in 19.5 (in PDF or PS). Branching ratios are shown in 19.3 (in PDF or PS). ^{19}O*(0.096) has g = 0.48 ± 0.06; its configuration appears to be mainly d^{3}_{5/2}, and B(M1) = 0.040 ± 0.015 μ^{2}_{N}. The ΔE value for the 1.47 → 0.096 transition is 1375.3 ± 0.5 keV. Assuming E_{f} = 96.0 ± 0.5 keV ( 19.2 (in PDF or PS)), E_{i} = 1471.4 ± 0.7 keV. Angular correlations are consistent with J^{π} = 5/2^{+} for the ground state and unambiguously fix J^{π} = 3/2^{+} and 1/2^{+}, respectively, for ^{19}O*(0.096, 1.47): see (1978AJ03) for references. See also (1986SE1B).
Differential cross sections were measured at E_{α} = 65 MeV and analyzed with DWBA calculations (1992YA08). See 19.7 (in PDF or PS).
Many measurements of the halflife have been reported (see ^{19}N) and a value of 0.304 ± 0.016 s has been adopted. A neutron emission probability of 33^{+}34_{11}% (1988MU08) and 62.4 ± 2.6% (1991RE02) has been measured. Shell model predictions for the ^{19}N(β^{})^{19}O decay are discussed in (1988WA17), and a β^{} delayed γ decay scheme for ^{19}O based on measurements of (1986DU07) (E_{γ} = 96.0 ± 1.0, 709.2 ± 0.8, and 3137.8 ± 1.0 keV with relative intensities of 100 ± 10, 63 ± 21, and 76 ± 21) is proposed. Arguments for J^{π} = (3/2^{+}) and (1/2, 3/2^{}) for the 3067 and 3232 keV levels are given. Evidence on the formation and decay of the 3945 keV complex of levels is reviewed. These calculations predict a ^{19}N half life of 0.54 s and a neutron emission probability P_{n} = 0.87. They also predict J^{π} = 1/2^{} for the ^{19}N ground state and branching ratios for decay to ^{19}O levels.
Transitions to ^{19}O*(0[u], 4.9, 6.3) have been observed in the radiative capture of stopped negative pions (1983MA16).
See (1986HEZW; E_{n} = 200 MeV).
Differential cross sections for the ^{19}O ground state and E_{x} = 0.1 MeV state were measured at E_{t} = 33 MeV (1991PI09). A DWBA analysis was carried out.
