A=18O (1972AJ02)

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).

3. ¹³C(⁷Li, d)¹⁸O Q_m = 5.681

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).

4. ¹⁴C(α, γ)¹⁸O Q_m = 6.228

Four resonances in the yield of capture γ-rays are observed for E_α = 0.50 to 3.00 MeV at E_α = 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 J^π = 4⁺, 1^-, 1^- and 5^- for ¹⁸O*(7.11, 7.62, 8.04, 8.12), as well as to J^π 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 E_p = 2.56 MeV (E_x = 8.22) with J^π = 2⁺.

5. ¹⁴C(α, n)¹⁷O Q_m = -1.819 E_b = 6.228

The relative neutron yield has been measured for E_α = 2.3 to 8.5 MeV: the parameters of observed resonances are displayed in Table 18.4 (in PDF or PS) (1956SA06, 1966BA03, 1970MO13).

6. ¹⁴C(α, α)¹⁴C E_b = 6.228

Observed anomalies in the scattering for E_α = 2 to 8.2 MeV shown in Table 18.4 (in PDF or PS) (1958WE29, 1970MO13). The yield of elastic scattering has been measured up to E_α = 16.5 MeV (1970MO13).

7. ¹⁴C(⁷Li, t)¹⁸O Q_m = 3.761

At E(⁷Li) = 20.4 MeV, triton groups are observed corresponding to a number of states of ¹⁸O with E_x < 12.6 MeV. Angular distributions were obtained for some of these, including ¹⁸O*(0, 1.98, 7.11, 11.69) with J^π = 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).

8. ¹⁵N(t, p)¹⁷N Q_m = -0.108 E_b = 15.834

See (1956SH96).

9. ¹⁵N(α, p)¹⁸O Q_m = -3.980

Not reported.

10. ¹⁶O(t, p)¹⁸O Q_m = 3.707

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).

Measurements of the angular correlation of cascade γ-rays require J = 0 and 2 for ¹⁸O*(3.63, 3.92). Lifetime measurements are reported by (1961LI03, 1963LI07): see Table 18.3 (in PDF or PS).

11. ¹⁷O(n, γ)¹⁸O Q_m = 8.047

See (1968FOZY, 1970CL1C).

12. ¹⁷O(n, n)¹⁷O E_b = 8.047

The coherent scattering length (thermal, bound) is 5.79 fm (1969BA1P). See also (1970TA1E; theor.).

13. ¹⁷O(n, p)¹⁷N Q_m = -7.896 E_b = 8.047

At E_n = 14.1 MeV, the cross section is 21.5 ± 1.7 mb (1970ME31). See also (1958RO1A, 1964AM02).

14. ¹⁷O(n, α)¹⁴C Q_m = 1.819 E_b = 8.047

The thermal cross section is 235 ± 5 mb (1961HA43). See also (1964ST25), (1964GA1A; theor.) and (1968FOZY) for a discussion of astrophysical implications.

15. ¹⁷O(d, p)¹⁸O Q_m = 5.822
Q₀ = 5.820 ± 0.010 (1965MO16).

Proton groups have been observed to most of the ¹⁸O states with E_x < 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 E_d = 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).

See also (1963EL04, 1964BA1G, 1966AR10, 1968SU1C; theor.).

16. ¹⁷O(¹⁷O, ¹⁶O)¹⁸O Q_m = 3.904

See (1967DA1E).

17. ¹⁸N(β^-)¹⁸O Q_m = 14.06

The decay is to ¹⁸O*(4.45): γ-rays with E_γ = 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).

18. (a) ¹⁸O(γ, n)¹⁷O Q_m = -8.047
(b) ¹⁸O(γ, p)¹⁷N Q_m = -15.943
(c) ¹⁸O(γ, α)¹⁴C Q_m = -6.227

For reaction (a) see (1963FU06, 1964MU12). For reaction (b) see (1955AJ61, 1964KO09, 1969HO16). See also (1965DO1E). For reaction (c), see (1964GR08).

19. ¹⁸O(e, e)¹⁸O

The ¹⁸O charge radius, r_rms = 2.727 ± 0.020 fm (using a distorted wave approximation), 2.766 ± 0.020 fm (using a Born approximation) (1970SI02). See also (1967DA1D, 1970SI1M).

At E_e = 69 MeV, the 180° scattering spectrum shows, in addition to the elastic peak, some weak structure corresponding to E_x = 2.0, 4.45 and 5.6 MeV. Somewhat stronger inelastic peaks are found corresponding to E_x = 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 E_x = 16.6, 18.4, 20.2, 21.9, 23.7, 25.2 and 26.9 MeV [all E_x values, ± 0.2 MeV] (1965VA04). See also (1961LA09, 1970CA1P).

See also (1962BA1D) and (1963BI05, 1963WI1B, 1966GR1H, 1967GR1B; theor.).

20. ¹⁸O(n, n)¹⁸O

Angular distribution measurements are listed in Table 18.8 (in PDF or PS) (1964EX1A, 1969ME15).

21. ¹⁸O(p, p)¹⁸O

A proton group is observed to the first excited state: E_x = 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: J^π = 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) [J^π = 0⁺, 2⁺, 4⁺, respectively] using polarized protons with E_p = 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).

See also (1964SC01, 1968BE34) and (1966RE1C, 1967LO1F, 1967SC16, 1970AG1C; theor.).

22. ¹⁸O(d, d)¹⁸O

At E_d = 15 MeV, inelastically scattered deuteron groups are reported to ¹⁸O states with E_x = 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).

23. ¹⁸O(t, t)¹⁸O

The angular distributions of elastically scattered tritons have been measured at E_t = 6.4 and 7.2 MeV (1964PU01). See also (1968HO1C).

24. ¹⁸O(³He, ³He)¹⁸O

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.).

25. ¹⁸O(α, α)¹⁸O

Angular distributions of elastically scattered α-particles have been measured at E_α = 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 J^π = 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 E_α = 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 E_x = 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: J^π = 3⁺ and 2^-, respectively for ¹⁸O*(5.37, 5.52) (1971OL06).

Alpha-γ correlation measurements involving ¹⁸O states below E_x = 6.4 MeV [see Table 18.2 (in PDF or PS)] lead to J^π = 1^- and 3^- for ¹⁸O*(6.19, 6.39). Other J^π values agree with previous assignments. The transitions 3.92 → 1.98 and 5.25 → 1.98 are almost pure M1 (1971BE45). See also (1968FA1A).

26. (a) ¹⁸O(⁷Li, ⁷Li)¹⁸O
(b) ¹⁸O(⁹Be, ⁹Be)¹⁸O
(c) ¹⁸O(¹⁰B, ¹⁰B)¹⁸O

For reaction (a) see (1969NE1E). For reactions (b) and (c) see (1971KN05).

27. (a) ¹⁸O(¹²C, ¹²C)¹⁸O
(b) ¹⁸O(¹³C, ¹³C)¹⁸O

For reaction (a) see (1967GO1A, 1968GO1H). For reaction (b) see (1971KN05).

28. ¹⁸O(¹⁶O, ¹⁶O)¹⁸O

See (1968GO1H, 1970FO1F, 1970SI09). See also (1965GO1G).

29. ¹⁸O(¹⁸O, ¹⁸O)¹⁸O

See (1970MO35, 1970SH07, 1971GO1T, 1971RA1C, 1971VA1H).

30. ¹⁸F(β⁺)¹⁸O Q_m = 1.655

See ¹⁸F.

31. (a) ¹⁹F(γ, p)¹⁸O Q_m = -7.993
(b) ¹⁹F(e, ep)¹⁸O Q_m = -7.993

See (1962DO1A). See also (1968AB09).

32. ¹⁹F(n, d)¹⁸O Q_m = -5.768

Angular distributions are reported at E_n = 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).

33. ¹⁹F(p, 2p)¹⁸O Q_m = -7.993

See (1971DE1F) and ¹⁹F.

34. ¹⁹F(d, ³He)¹⁸O Q_m = -2.499

Many states of ¹⁸O have been populated in this reaction: see Table 18.9 (in PDF or PS) (1965ZE04, 1969KA1A, 1970KA31). See also (1967WI1F) and (1968BA2J; theor.).

35. ¹⁹F(t, α)¹⁸O Q_m = 11.821

Alpha groups are reported at E_t = 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 E_x = 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).

36. ²¹Ne(n, α)¹⁸O Q_m = 0.698

See (1961AB05).