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GENERAL: See also Table 20.1 [Table of Energy Levels] (in PDF or PS).

Theory: See (1957RA1C).

1. 20F(β-)20Ne

Qm = 7.050

See ²⁰Ne.

2. 17O(α, p)20F

Qm = -5.659

Not observed.

3. 18O(d, n)19F

Qm = 5.737

Eb = 12.343

See ¹⁹F.

4. 18O(d, p)19O

Qm = 1.731

Eb = 12.343

The proton yield has been measured from E_d = 0.79 to 0.88 MeV (1956AH1A). See also (1959ZI16) and ¹⁹O.

5. 18O(d, α)16N

Qm = 4.237

Eb = 12.343

The cross section has been measured for E_d = 0.5 to 3.0 MeV. Resonances are observed at E_d = 1.40, 1.75, 2.15, and 2.90 MeV, with widths of 500, 400, 300, and 600 keV, respectively, corresponding to ²⁰F*(13.60, 13.92, 14.28, and 14.95 MeV) (1957BO04). See also ¹⁶N.

6. 18O(t, n)20F

Qm = 6.085

See (1956SH1A).

7. 18O(3He, p)20F

Qm = 6.850

Not reported.

8. 18O(α, d)20F

Qm = -11.501

Not reported.

9. 19F(n, γ)20F

Qm = 6.606

The thermal capture cross section is 9.4 ± 2 mb (1947SE33). The γ-spectrum has been measured by (1957CA28) who find transitions with E_γ (corrected for recoil) of 6.600 ± 0.011, 6.019 ± 0.011, 5.54 ± 0.02, 5.28 ± 0.02, and 5.10 ± 0.02 MeV, with intensities of 30, 16, 24, 27, and 14 photons per 100 captures, respectively. The 6.60 MeV line is the ground state transition; the other transitions are not uniquely determined. Upper limits for transitions to ²⁰F*(0.65, 0.83, and 0.99 MeV) are 1, 3, and 7 photons per capture, respectively. The γ-rays of energy 5.54 and 5.28 MeV may result from transitions to ²⁰F*(1.06 and 1.31) (1957CA28). Two resonances for ²⁰F production are observed at E_n = 280 and 590 keV, with widths ≈ 20 keV and peak cross sections of 1.2 and 1.3 mb, respectively; ωΓ_γ ≈ 15 eV (1950HE92). A number of additional resonances appear in the range E_n = 25 to 2000 keV: see (1958HU18). See also (1951KI35).

10. 19F(n, n)19F

Eb = 6.606

The coherent scattering cross section is 3.8 ± 0.3 b; the total cross section (epithermal, bound) is 4.0 ± 0.1 b (1958HU18). The cross section is approximately constant at ≈ 3.7 b from 0.02 eV to 20 keV (1958HU18). Resonances in the total cross section are listed in Table 20.2 [Resonances in ¹⁹F(n, n)¹⁹F] (in PDF or PS). The J^π assignments indicated for the first three levels (p-wave) are based on elastic scattering distributions and total cross sections (1958BL54).

Total cross sections have been measured to E_n = 5 MeV by (1958WI36), from E_n = 3 to 14 MeV by (1954NE03), from E_n = 3.8 to 8.1 MeV by (1957BO13), from E_n = 4.4 to 5.6 MeV by (1956BE98) and from E_n = 7 to 14 MeV by (1958BR16). The cross section shows structure at least as high as E_n ≈ 7.5 MeV: see (1956BE98, 1957BO13, 1958WI36). For the presentation of the data as a whole, see (1958HU18). Angular distributions have been measured and phase shifts determined at five energies in the range E_n = 0.66 to 2.92 MeV by (1958WI36). See also (1955PA1B, 1957LA14) and (1956NE1C; theor.).

11. 19F(n, n')19F*

Eb = 6.606

Observed resonances in the yield of 0.1 and 0.2 MeV γ-radiation (see ¹⁹F) for E_n < 1 MeV are exhibited in Table 20.3 [Resonances in ¹⁹F(n, n'γ)¹⁹F] (in PDF or PS). A satisfactory fit to the excitation function for E_n < 300 keV is obtained on the assumption for p-wave resonances at E_n = 100 and 260 keV. The excitation functions for 0.1, 0.2, 1.24, and 1.37 MeV γ-rays have been measured to E_n = 2.2 MeV (1955FR1B).

The cross section for excitation of ¹⁹F*(2.79) has been studied from E_n = 3 to 3.6 MeV. The very slow rise for the first 300 keV above threshold suggests a large spin difference between the 2.79 MeV level and the ground state (1957FR57). See also (1955AJ61, 1956VA29).

12. 19F(n, 2n)18F

Qm = -10.414

Eb = 6.606

The cross section at E_n = 14.1 MeV is 62 mb (1958AS63); at E_n = 14.5 MeV it is 60 mb (1953PA1C). See also (1952AJ38, 1958RA1H).

13. 19F(n, p)19O

Qm = -4.006

Eb = 6.606

The excitation function has been measured from E_n = 4.7 to 8.0 MeV; it shows a single broad maximum at 7.5 MeV. For E_n < 8 MeV, the (n, α) cross section is at least twice as large as the (n, p) cross section (1955MB01). At E_n = 14.5 MeV, σ(n, α)/σ(n, p) = 1.2 ± 0.4 (1958KO03); σ(n, p) = 135 mb (1953PA1C). See (1958HU18).

14. 19F(n, α)16N

Qm = -1.500

Eb = 6.606

Observed resonances are listed in Table 20.4 [Resonances in ¹⁹F(n, α)¹⁶N] (in PDF or PS) (1955BO98, 1955MB01 : see graph in (1958HU18 )). See also (1937WI1A , 1955BO1C , 1955GR18 , 1958KO03).

15. 19F(d, p)20F	Qm = 4.379
	Q0 = 4.383 ± 0.015 (1957KH16);
	Q0 = 4.38 ± 0.03 (1956EL1A).

Energy levels of ²⁰F derived from the proton groups are listed in Table 20.5 [Proton groups from ¹⁹F(d, p)²⁰F] (in PDF or PS) (1952WA1A, 1956EL1A, 1957KH16). The J^π assignments given in the table result from analysis of angular distributions by stripping theory. The angular distribution of the ground state protons has been studied at a number of energies (1953BR1C, 1956TA1D, 1956VA17, 1957ON1A, 1957SE1D). The pattern varies strongly with energy, suggesting compound nucleus interaction rather than stripping: it is concluded that an earlier assignment of J = 1⁺ (1953BR1C) is not supported (1957SE1D). See also (1956OK1A, 1956TO1C; theor.). At E_d = 1.05 MeV, γ rays are observed with E_γ = 0.64 and 1.06 MeV (1954TH1B).

It is of interest to note that among the levels of ²⁰F there occur seven groups with equal spacings of 165n keV, where n is an integer for each group (1952WA1A, 1956EL1A). Above E_x = 5 MeV, only odd parity levels appear; below this value, even parities predominate. The levels appear in groups of the same parity, separated by ≈ 0.6 MeV (1956EL1A).

16. 20Ne(n, p)20F

Qm = -6.267

Not observed.

17. 20Ne(t, 3He)20F

Qm = -7.032

Not observed.

18. 21Ne(n, d)20F

Qm = -10.797

Not observed.

19. 21Ne(d, 3He)20F

Qm = -7.530

Not observed.

20. 21Ne(t, α)20F

Qm = 6.789

Not observed.

21. 22Ne(n, t)20F

Qm = -14.905

Not observed.

22. 22Ne(p, 3He)20F

Qm = -15.670

Not observed.

23. 22Ne(d, α)20F

Qm = 2.681

Alpha particle groups have been observed at E_d = 7.8 MeV corresponding to the ground state and to a level at 0.57 ± 0.13 MeV (1951MI1A).

24. 23Na(n, α)20F

Qm = -3.888

See (1950JE1A).