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19O (1972AJ02)(See Energy Level Diagrams for 19O) GENERAL: See also (1959AJ76) and Table 19.1 [Table of Energy Levels] (in PDF or PS). Shell model: (1957WI1E, 1959BR1E, 1960TA1C, 1962SH1B, 1962TA1B, 1963PA03, 1964CO24, 1964IN03, 1965FE02, 1966AR10, 1966IN01, 1966LA1E, 1967BO09, 1967EN01, 1967FE01, 1967FL13, 1967IN03, 1967PI1B, 1968AR02, 1968CO1N, 1968EL1C, 1968GU1E, 1968HA17, 1968HA1P, 1968MO1G, 1969FE1A, 1969HO32, 1969KU1G, 1969MA1T, 1970TA1J, 1971AR25, 1971WI01). Cluster, collective and deformed models: (1963CH02, 1965FE02, 1969FE1A). Astrophysical questions: (1970BA1M). Electromagnetic transitions: (1963CH02, 1965FE02, 1967FE01, 1967IN03, 1968EL1C, 1968HA17, 1971AR25). Special levels: (1959LA1A, 1960GO1C, 1967EN01, 1967PR04, 1968AR02, 1968CO1N, 1968HA1P, 1968YA03, 1969FE1A). Other theoretical topics: (1964IN03, 1965FO1D, 1967FL13, 1968CO1N, 1968GU1E, 1968MO1G, 1968MU1B, 1968PA1Q, 1968SU1C, 1969MA1T, 1971LA1D, 1971LE1H). Ground state properties: (1964ST1B, 1968EL1C, 1971AR25, 1971WI01).
The half-life of 19O is 29.12 ± 0.26 sec (1962MA38), 27.2 ± 0.3 sec (1965BO42), 26.76 ± 0.08 sec (1967YU01), 27.1 ± 0.1 sec (1970AL21): the weighted mean of the last three values is 26.91 ± 0.08 sec. The decay is complex: see 19F.
The lifetimes of the excited states of 19O at 95.1 ± 0.1 and 1468 keV are, respectively, τm = 1.89 ± 0.2 nsec and 18 ± 10 psec (1969NI09): see, however, Table 19.2 (in PDF or PS). |M|2 values are also listed. See also (1968FA04, 1970BA1Y, 1970FA01, 1971KN05).
Proton groups corresponding to 19O states with Ex < 5.6 MeV have been observed by (1964MO24, 1965MO19: Et = 5.55 MeV) and (1965WI1B, 1966WI05: Et = 12.0 MeV): level parameters and L values derived from angular distribution analyses are displayed in Table 19.3 (in PDF or PS). Excitation energies from Eγ measurements, and lifetime measurements are reported in Tables 19.3 (in PDF or PS) and 19.2 (in PDF or PS), respectively (1971BR02, 1971HI06).
In the energy interval En = 0.2 to 1.0 MeV, the capture cross section displays a resonance at En ≈ 0.6 MeV (1964VA02). Astrophysical considerations are discussed by (1968FOZY, 1970CL1C).
The coherent scattering amplitude (bound) is a = 6.00 fm (1969BA1P). The total cross section measured for En = 0.14 to 2.47 MeV shows four resonances at En = 0.66, 1.19, 1.26, 1.84 and 2.45 MeV [see Table 19.4 (in PDF or PS)], in addition to a broad maximum at En = 1.6 MeV and resonance structure near 2.3 MeV (1965VA03). A phase-shift analysis by (1964DO08) is consistent with the (1965VA03) results and suggests that the two broad structures can each be accounted for in terms of two levels whose parameters are displayed in Table 19.4 (in PDF or PS). At higher energies [En = 2.82 to 4.17 MeV (1959SC30), 2.45 to 8.50 MeV and 10.6 to 19.0 MeV (1965SA24)] the total cross section shows additional structures. At En = 14.1 MeV, σt = 1610 ± 70 mb (1969ME15). See also (1964EX1A) and 18O.
See (1964AM02).
The total cross sections for the α0 and α1 groups have been measured for En = 7.5 to 8.6 MeV: resonance structure is reported at En = 7.70 ± 0.05 and 8.05 ± 0.05 MeV with Γlab = 0.25 and 0.35 MeV, respectively [19O*(11.25, 11.58)] (1967ST28). See also (1964GA1A).
Angular distributions of proton groups have been measured at Ed = 0.8 MeV (1957SJ66), 5 MeV (1969FI07), 5.56 MeV (1964MO25, 1965MO16), 7.0 MeV (1964WI05), 10 MeV (1964EL1A), 12 MeV (1965WI1B, 1966WI05, 1971FO18), 12.3 MeV (1965LU1A), 14.95 MeV (1963YA03) and 15 MeV (1961AR06). ln values derived from these measurements, as well as other level parameters for 19O states below Ex = 7.3 MeV, are displayed in Table 19.3 (in PDF or PS). See also (1959AJ76) and reaction 23 in 19F. Branching ratios for the decays of 19O*(0.096, 1.47, 2.37, 2.78, 3.16, 3.95) are shown in Table 19.5 (in PDF or PS) (1965AL13, 1969FI07, 1970FI08, 1971BR02, 1971HI06, 1971MC11). Angular correlation measurements are consistent with Jπ = 5/2+ for the ground state and unambiguously fix Jπ = 3/2+ and 1/2+, respectively, for 19O*(0.096, 1.47) (1965AL13). They also suggest J = 9/2 for 19O*(2.37) and 7/2+ for 19O*(2.78) (1971HI06). These assignments are also consistent with the lifetime measurements for these two states shown in Table 19.2 (in PDF or PS) (1959ZI16, 1965MC10, 1971BR02, 1971HI06, 1971MC11). Measurement of the internal conversion coefficient for the 0.096 MeV transition shows that it is M1 (1963GI12). See also (1959WI39, 1961LO10, 1964MA57) and (1963RO12, 1966AR10, 1967BU23, 1967ST1H, 1968ST1K, 1968SU1C, 1968YA03; theor.).
Not reported.
Not reported.
See (1971KN05).
Angular distributions are reported at En = 14.1 MeV (1968FA01; p0, p1, p2, punres.) and 14.4 MeV (1968AN1F, 1968RE07; p0+1, p2, punres.). See also (1961KO06, 1970FO1G), (1959AJ76) and 20F.
Not reported.
Not reported.
Not reported.
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