(See Energy Level Diagrams for 18O)
Shell model: (1957WI1E, 1960TA1C, 1962HO1C, 1962TA1B, 1962TA1D, 1963HA05, 1963PA03, 1963SA07, 1964CO24, 1964IN03, 1964MC1A, 1964PA1D, 1964WA1F, 1965BA1J, 1965BE1T, 1965DE1H, 1965EL06, 1965EN02, 1965FE1B, 1965FE02, 1965NA1A, 1965ZA1B, 1966AR10, 1966BA2E, 1966BA2C, 1966BO25, 1966BR1R, 1966HU09, 1966IN01, 1966KU05, 1966LA1E, 1966LE11, 1966RI1F, 1966RO01, 1967BA04, 1967BR1G, 1967EN01, 1967FE01, 1967FL01, 1967GR09, 1967GR1D, 1967HO11, 1967IN03, 1967KU09, 1967KU13, 1967LA1H, 1967LY02, 1967MO1J, 1967PA05, 1967PA1K, 1967PI1B, 1967RO1F, 1967ST02, 1967VI1B, 1967WO1C, 1968AR02, 1968BE1T, 1968BH1B, 1968CL03, 1968CO1N, 1968DE1M, 1968DE13, 1968DW1A, 1968EL1C, 1968FR03, 1968GA06, 1968GA16, 1968GU1E, 1968GU1C, 1968GU1G, 1968HA17, 1968HA1P, 1968HE1H, 1968KA1E, 1968KA1C, 1968KO1L, 1968KU1E, 1968NA09, 1968NA19, 1969BA2F, 1969BE1T, 1969BU15, 1969EL1B, 1969FE1A, 1969GU1E, 1969HO32, 1969IG1A, 1969KA07, 1969KA09, 1969KU1G, 1969MA1T, 1969ME06, 1969SA1F, 1969ST1G, 1969UL03, 1969VO1E, 1969ZU03, 1970BA2E, 1970EL1G, 1970EL08, 1970GA1J, 1970HA49, 1970KA32, 1970TA1J, 1970TR08, 1970TR07, 1971AR1R, 1971EL07, 1971HO12, 1971JA06, 1971LO23, 1971MO05, 1971PR16, 1971QU01, 1971UL04, 1971VI08, 1971WI01, 1972GA02).
Cluster, collective and deformed models: (1959YU1A, 1963MA1D, 1964BR1H, 1965FE1B, 1965FE02, 1966BE29, 1966BR1Q, 1966HA1K, 1966RI1F, 1966RO01, 1967BH07, 1967BR1G, 1967FE01, 1967GR1D, 1967PA1K, 1967RO1F, 1968EL1C, 1969BA2E, 1969DR1B, 1969FE1A, 1969ZA1D, 1970BA2B, 1970TR07, 1971AR1R, 1971UL04).
Astrophysical questions: (1970BA1M).
Electromagnetic transitions: (1963BU11, 1964BR1H, 1965EL06, 1965EN02, 1965FE02, 1965ST22, 1966BO25, 1967GR1D, 1967IN03, 1967LA1H, 1968EL1C, 1968HA17, 1968LA1G, 1968LE02, 1968SH06, 1969BE1T, 1969BE22, 1970EL08, 1970HA49, 1970TR07).
Special levels: (1960EV1A, 1962DA04, 1962TA1B, 1964BR1H, 1964EN1A, 1964MC1A, 1965BE1T, 1965LE1C, 1966BO25, 1966BR1R, 1966HU09, 1966MI1G, 1967BH07, 1967EN01, 1967FL01, 1967GR09, 1967PA1K, 1967VI1B, 1968AR02, 1968BH1B, 1968CO1N, 1968FR03, 1968GA06, 1968GA16, 1968HA1P, 1968KA1C, 1968LE02, 1968NA09, 1969BA1Z, 1969BE1T, 1969FE1A, 1969KA09, 1969KA29, 1969MA1T, 1969ME06, 1969OS01, 1970EL1G, 1970EL08, 1970GA1J, 1970HO17, 1971AR1R, 1971EL07, 1971JA06, 1971PR16, 1971QU01, 1971UL01, 1971WI01, 1972GA02).
Other theoretical topics: (1961BA1D, 1962DA04, 1963BU11, 1963VL1A, 1964EN1A, 1964HE1C, 1964IN03, 1964TR1A, 1964WA1E, 1965DE1H, 1965ER04, 1965GO1F, 1965KA1B, 1965KA1C, 1965NA1A, 1965NI1A, 1965ZA1B, 1966BR1R, 1966BR1P, 1966DA1E, 1966DO1C, 1966GI1A, 1966KU05, 1966LE11, 1966OL1C, 1966SU1D, 1966WA1H, 1966YO1B, 1967FE01, 1967FL01, 1967GR09, 1967KU1G, 1967KU13, 1967MO1J, 1967ST02, 1967VA31, 1967WO1C, 1968BA2H, 1968BE1T, 1968BL1G, 1968CO1N, 1968DE1M, 1968DW1A, 1968EL1C, 1968GU1E, 1968GU1C, 1968GU1F, 1968GU1G, 1968JO1E, 1968KA1C, 1968KO1K, 1968LE02, 1968MU1B, 1968NE1C, 1968SU1C, 1968SU1D, 1968VA24, 1969DE06, 1969JA1P, 1969JO1L, 1969KA29, 1969MU09, 1969OS01, 1969RA28, 1969SO08, 1970AG1C, 1970BA1Z, 1970DI1G, 1970EL08, 1970GA1J, 1970PR1D, 1970SU1B, 1971BA14, 1971BO21, 1971DZ06, 1971EL07, 1971LA1D, 1971LE1H, 1971LO23, 1971PR16, 1971SC01, 1971UL01, 1971VI08, 1972GA02).
Ground state: (1971MO05).
Cross sections to various of the final states have been measured at E(7Li) = 5.00 MeV (1966MC05).
Radiative decay and lifetime measurements are reported by (1964ES02): see Tables 18.2 (in PDF or PS) and 18.3 (in PDF or PS). Angular distributions have been measured at E(7Li) = 3.24 to 3.64 MeV (1967MO23; p0, p1). See also (1960SH05, 1970CA1N).
Gamma-ray energies of 1982.3 ± 0.8 [1.98 → 0], 1571.9 ± 2.5 [3.55 → 1.98], 1649.8 ± 2.2 [3.63 → 1.98] and 1938.6 ± 2.1 keV [3.92 → 1.98], due to the transitions shown in brackets, have been measured by (1969TH01).
Four resonances in the yield of capture γ-rays are observed for Eα = 0.50 to 3.00 MeV at Eα = 1.14, 1.79, 2.33 and 2.44 MeV: see Table 18.4 (in PDF or PS). Gamma-ray angular distribution and correlation measurements lead to Jπ = 4+, 1-, 1- and 5- for 18O*(7.11, 7.62, 8.04, 8.12), as well as to Jπ assignments for lower states involved in the cascade decay: see Table 18.2 (in PDF or PS) (1958GO1A, 1958PH37, 1966LE1B, 1967LE02). (1970DU1D) report resonance at Ep = 2.56 MeV (Ex = 8.22) with Jπ = 2+.
At E(7Li) = 20.4 MeV, triton groups are observed corresponding to a number of states of 18O with Ex < 12.6 MeV. Angular distributions were obtained for some of these, including 18O*(0, 1.98, 7.11, 11.69) with Jπ = 0+, 2+, 4+, 6+. The latter two are the most strongly populated in this reaction: they appear to be part of the ground state rotational band (1970MO17).
Proton groups corresponding to many states of 18O have been reported by (1960JA13, 1960JA17, 1962HI06): see Table 18.5 (in PDF or PS). The L assignments displayed there have been derived from PWBA analysis of angular distributions, principally those obtained by (1964MI05). For a complete summary of angular distribution measurements, see Table 18.6 (in PDF or PS).
See also (1964GA1B), (1967CH1L, 1967OG1A) and (1963RO1C, 1964TR1A, 1965GL07, 1965MA1L, 1965SH1E, 1966GL1C, 1966GL1D, 1966SH1F, 1966ST1F, 1967DO1B, 1967MA1E, 1967VE1B, 1968KO04, 1968KO1K, 1969LI1G, 1969SO08; theor.).
Proton groups have been observed to most of the 18O states with Ex < 8 MeV (1963YA03, 1965MO16, 1966WI07): see Table 18.7 (in PDF or PS). See also (1959AJ76) and (1964HE11, 1965WI1B). Angular distributions of the protons to the relatively strongly populated states have been measured at Ed = 5.55 to 14.95 MeV and analyzed by PWBA (1957BI80, 1964MO25, 1965MO16, 1966WI07). Proton-γ coincidence measurements by (1967MO09) are displayed in Table 18.2 (in PDF or PS) and a lifetime measurement for 18O*(1.98) by (1969NI09) is shown in Table 18.3 (in PDF or PS).
The decay is to 18O*(4.45): γ-rays with Eγ = 0.82 ± 0.02, 1.65 ± 0.02, 1.98 ± 0.02 and 2.47 ± 0.03 MeV with intensities 0.60 ± 0.03, 0.63 ± 0.04, 1.00 ± 0.04 and 0.43 ± 0.03 have been observed. These are due to the decay of 18O*(4.45) to 18O*(3.63, 1.98) and the subsequent decay of these two states (1964CH19).
At Ee = 69 MeV, the 180° scattering spectrum shows, in addition to the elastic peak, some weak structure corresponding to Ex = 2.0, 4.45 and 5.6 MeV. Somewhat stronger inelastic peaks are found corresponding to Ex = 10.9, 12.6, 14.0 and 15.1 MeV. In addition six prominent peaks, each of about the same strength and assumed to arise from giant dipole excitations, are observed at Ex = 16.6, 18.4, 20.2, 21.9, 23.7, 25.2 and 26.9 MeV [all Ex values, ± 0.2 MeV] (1965VA04). See also (1961LA09, 1970CA1P).
A proton group is observed to the first excited state: Ex = 1.981 ± 0.004 MeV (1957YO04). Angular distribution measurements reported by (1961CA02, 1965PR1D, 1971LE1R, 1971RE20) are displayed in Table 18.8 (in PDF or PS). The transition from 18O*(3.63) to the ground state has been determined to be EO: Jπ = 0+ for the 3.63 MeV state (1963GO32, 1965GO11, 1967CO30). Proton-γ angular correlation measurements establish J = 2 and 1 for 18O*(3.92, 4.45) (1965OL02), and J = 3, 2, 0, 3 and (2) for 18O*(5.09, 5.25, 5.33, 5.37, 5.52), respectively (1966LO12): see Table 18.2 (in PDF or PS) for branching ratios obtained by (1964GO11, 1965OL02, 1966LO12). Angular distributions to 18O*(0, 1.98, 7.11) [Jπ = 0+, 2+, 4+, respectively] using polarized protons with Ep = 22.5 and 24.5 MeV have been analyzed with the rotational model: β2 = 0.37 ± 0.03 and β4 = 0.18 ± 0.04. The results confirm the assignment of 18O*(7.11) to the ground state rotational band (1971RE20).
At Ed = 15 MeV, inelastically scattered deuteron groups are reported to 18O states with Ex = 1.982, 3.564 ± 0.025, 3.655 ± 0.030, 3.949 ± 0.030, 4.501 ± 0.040, 5.139 ± 0.030, 5.301 ± 0.030, 5.413 ± 0.035 MeV (1961AR06). Angular distribution measurements by (1961AR06, 1964WI05, 1965DI1C, 1965LU1A, 1966DE09) are listed in Table 18.8 (in PDF or PS). See also (1959AJ76).
Angular distributions of elastically scattered 3He ions have been studied at E(3He) = 11.0 to 17.3 MeV: see Table 18.8 (in PDF or PS) (1968HA30, 1969HA1U, 1969ZU02, 1970BO25, 1970GR04). See also (1968HO1C) and (1969MA1G; theor.).
Angular distributions of elastically scattered α-particles have been measured at Eα = 21.4 (1966LU05) and 40.5 MeV (1966HA19): see Table 18.8 (in PDF or PS). The transitions to 18O*(4.45, 5.09) are L = 1 and 3, respectively, fixing Jπ = 1- and 3- for these states. B(E2) values for 18O*(1.98, 4.45) and B(E3) for 18O*(5.09) are also reported (1966HA19).
Measurements of α groups near 180° for Eα = 20.0 to 23.4 MeV confirm assignments of natural parity for 18O*(1.98, 3.55, 3.63, 3.92, 4.45, 5.09, 5.25, 5.33, 6.19, 6.39, 7.11, 7.62, 7.85, 8.21, 8.28, 8.82, 8.96, 9.03, 9.10, 9.36, 9.39, 9.68, 9.72 ± 0.03, 9.88, 10.12, 10.29, 10.38, 11.62, 11.69). The levels at Ex = 5.37, 8.48 and 8.64 MeV were not observed, and those at 5.52, 6.34 and 6.86 MeV were populated weakly indicating unnatural parity: Jπ = 3+ and 2-, respectively for 18O*(5.37, 5.52) (1971OL06).
Alpha-γ correlation measurements involving 18O states below Ex = 6.4 MeV [see Table 18.2 (in PDF or PS)] lead to Jπ = 1- and 3- for 18O*(6.19, 6.39). Other Jπ values agree with previous assignments. The transitions 3.92 → 1.98 and 5.25 → 1.98 are almost pure M1 (1971BE45). See also (1968FA1A).
Angular distributions are reported at En = 14 MeV (1965SA14; d0), 14.1 MeV [(1957RI44; d0, d1), (1959VE19, 1960VE06; d0) and (1968FA01; d0, d1)] and at 14.4 MeV (1968AN1F, 1968RE07; d0, d1). See also (1961BO1A, 1961KO06, 1961LE1D, 1969BE1R, 1971MI1H).
Alpha groups are reported at Et = 5.75 to the thirteen excited states reported in the 16O(t, p)18O reaction [see Table 18.5 (in PDF or PS)] and to states with Ex = 6.86, 7.10, 7.60, 7.75, 7.84, 7.96, 8.02, 8.11, 8.19, 8.26, 8.39, 8.48, 8.64 MeV (± 20 keV) (1962HI06). Branching ratios are reported by (1967CH1D): see Table 18.2 (in PDF or PS). See also (1966BE1G, 1967CH1L, 1967CHZY, 1968BE1U). See also (1967CA1L).