A=20Ne (1998TI06)

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²⁰Ne (1998TI06)

(See Energy Level Diagrams for ²⁰Ne)

GENERAL: See 3 [Electromagnetic Transitions in A = 20] (in PDF or PS), 20.16 [General Table] (in PDF or PS), 20.17 [Table of Energy Levels] (in PDF or PS) and 20.18 [Radiative decays in ²⁰Ne] (in PDF or PS).

Static quadrupole moment: Q_1.63 = -0.23 ± 0.03 e · b (1989RA17).

μ_1.63 = 1.08 ± 0.08 nm (1989RA17).

B(E2)(↑) [0 → 1.63] = 0.0330 ± 0.0015 e² · b² (1978GR06). See also (1987RA01).

Intrinsic hexadecapole moment: Q_4.25 = 0.022 ± 0.003 e² · b² (1978GR06).

μ_4.25 = 0.52 ± 0.60 nm (1989RA17).

Isotopic abundance: (90.51 ± 0.09)% (1984DE53).

1. ⁹Be(¹⁸O, ²⁰Ne)⁷He Q_m = -8.502

Observation of ²⁰Ne in this reaction and measurement of the cross section was reported by (1990BEYY).

2. (a) ¹⁰B(¹⁰B, ¹⁰B)¹⁰B E_b = 31.144
(b) ¹⁰B(¹⁰B, α)¹⁶O Q_m = 26.414

Excitation functions have been measured for E(¹⁰B) = 6 to 30 MeV (reaction (a)) and 6 to 20 MeV (reaction (b)). Large resonant structures are observed in reaction (b), particularly at E_x ≈ 38 MeV (α₀) and 38.6 MeV (α to ¹⁶O* (7.0, 10.3, 16.2 (u)), Γ ≈ 0.6 MeV. See also (1983KAZF) and (1978AJ03). More recently, cross sections for fusion of ¹⁰B + ¹⁰B were measured for E(¹⁰B) = 1.5 - 5 MeV/nucleon, and evidence for fissionlike decay of ²⁰Ne was observed (1989SZ01). Mass distributions from the sequential decay of the compound nucleus measured at E(¹⁰B) ≈ 110 MeV show no evidence for nuclear structure effects (1993SZ02).

3. ¹⁰B(¹⁴N, α)²⁰Ne Q_m = 19.531

Angular distributions of α-particles to many states of ²⁰Ne below E_x = 10.7 MeV have been measured at E(¹⁴N) = 23.5 to 35 MeV. See also (1978AJ03, 1983AJ01). Numerical calculations of differential cross sections using CWBA and DWBA are reported by (1990OS1B).

4. ¹⁰B(¹⁶O, ⁶Li)²⁰Ne Q_m = 0.270

At E(¹⁶O) = 19.5 to 42 MeV angular distributions for the ⁶Li ions corresponding to transitions to ²⁰Ne*(0, 1.63, 4.25, 4.97, 5.62 + 5.79, 6.7 - 7.2) are in good agreement with Hauser-Feshbach calculations. See also (1978AJ03, 1985ST1B).

5. ¹¹B(¹⁶O, ⁷Li)²⁰Ne Q_m = -3.935

At E(¹¹B) = 115 MeV, angular distributions are reported to ²⁰Ne*(7.16, 8.78, 10.26, 11.95, 15.4). ²⁰Ne*(8.78, 15.4, 17.3, 21.0 ± 0.07, 22.78 ± 0.06) are particularly strongly populated. It is suggested that these five states have J^π = 6⁺, 7^-, (8⁺), 9^-, and 9^-: see (1983AJ01).

6. ¹²C(⁹Be, n)²⁰Ne Q_m = 10.319

At E(⁹Be) = 16 and 24 MeV, angular distributions have been measured for ²⁰Ne*(7.3 ± 0.4, 9.2 ± 0.4, 10.9 ± 0.3, 12.2 ± 0.3, 15.7 ± 0.3): see (1983AJ01).

7. (a) ¹²C(¹⁰B, d)²⁰Ne Q_m = 5.957
(b) ¹²C(¹¹B, t)²⁰Ne Q_m = 0.760

At E(¹²C) = 45 MeV the population of states of ²⁰Ne with E_x = 8.46, 8.78, 9.03, 10.61, 10.67, 10.99, 11.01, 11.66, 11.94, 12.14, 12.39, 12.58, 12.73, 13.05, 13.17, 13.34 [7^-], 13.69, 13.91, 14.29, 14.36, 14.81, 15.17 [6⁺], 15.38 [7^-], 15.71 [(7,8)], 15.89[(7)], 16.16, 16.22, 16.51 [(8)], 16.73, 17.39 [9^-], 18.18 and 18.32 MeV is reported (1976KL03). [Values in brackets are J^π suggested on basis of Hauser-Feshbach calculations. The underlined states are well resolved: the authors indicate ± 20 keV for such states.] The relative intensities of the groups to ²⁰Ne*(17.39, 15.38) [J^π = 9^-, 7^-] argue against the existence of a superband: see (1978AJ03). See also (1983AJ01).

8. ¹²C(¹²C, α)²⁰Ne Q_m = 4.617

Double and triple (α, α, γ) correlations and γ-ray branching measurements [see 20.18 (in PDF or PS)] lead to the J^π assignments shown in 20.19 (in PDF or PS). See 20.20 (in PDF or PS) for assignments to rotational bands. Angular distributions for many states have been reported at E(¹²C) = 4.9 to 51 MeV [see (1978AJ03, 1983AJ01, 1987AJ02)], at 5.2 to 5.8 MeV (1988BA12; α₀), and at 69.5 MeV (1985XI1B). At E(¹²C) = 38 to 64 MeV, ²⁰Ne*(7.17, 7.83, 8.54, 8.78, 9.03, 11.95, 12.13, 12.59, 13.90) are strongly populated and subsequently decay to ¹⁶O_g.s. (1987RA02). Alpha decay of the J^π = 6⁺ level at E_x = 15.16 MeV and the J^π = 8⁺ level at E_x = 18.54 MeV to the first excited state of ¹⁶O was studied by (1992LA01). See 20.19 (in PDF or PS). For γ-decay measurements see (1987FI01), 20.19 (in PDF or PS) and (1978AJ03). Resonant characteristics of statistical fluctuations in ¹²C(¹²C, α)²⁰Ne leading to the 12 lowest ²⁰Ne states were studied by (1993GA02).

The yields of various groups of α-particles and their relevance to states of ²⁴Mg, and fusion cross sections, have been studied by many groups: see (1978AJ03, 1983AJ01, 1987AJ02).

Sub-Coulomb cross sections calculated in a statistical framework are discussed in (1990KH05). A review of the state of theory and experiments on ¹²C + ¹²C reactions with formation of molecular states is presented in (1987DA1L).

See also (1987ER1B, 1988GO1G, 1988DE18, 1991SZ02).

9. (a) ¹²C(¹⁴N, ⁶Li)²⁰Ne Q_m = -4.181
(b) ¹²C(¹⁴N, d)²⁴Mg → α + ²⁰Ne Q_m = 7.480

Angular distributions of the ⁶Li ions to many states of ²⁰Ne below 17.5 MeV have been reported for E(¹⁴N) = 30 to 78 MeV and E(¹²C) = 67.2 MeV. At the latter energy ²⁰Ne*(16.67, 17.38, 18.11, 19.16, 19.6) are particularly strongly populated: see (1978AJ03). For reaction (b) to ²⁰Ne_g.s. see the angular correlation measurements at E(¹⁴N) = 30 - 42 MeV reported by (1988AR24, 1994ZU03), and see the review of (1987GO12). An analysis of differential cross sections and angular correlation functions within a compound nuclear model is described in (1994BE55). Earlier work is cited in (1987AJ02). See also (1988BEYB, 1989BEXN, 1992ARZX).

10. (a) ¹²C(¹⁶O, ⁸Be)²⁰Ne Q_m = -2.636
(b) ¹²C(¹⁶O, αα)²⁰Ne Q_m = -2.545

Reaction (a) was studied at 150 MeV in a search for high-spin α-cluster resonances in ²⁰Ne. A broad 10⁺ resonance was located at 27.5 MeV (1988AL07). See also (1988CAZV, 1994RA04).

Excitation functions in the range E_cm = 25.7 - 38.6 MeV were measured by (1993ES01). See also the comment (1993ZH21) and reply (1993ES03) on the work. Excitation functions for reaction (a) leading to members of the ²⁰Ne ground state rotational band were measured for E_cm = 22 - 29 MeV by (1995SU06).

A triple coincidence measurement of reaction (b) through the ²⁰Ne 6⁺ level at E_x = 8.78 MeV was reported by (1989WUZZ). α - α coincidence measurements by (1994KU18) at E_cm = 26.9 MeV were used to study the connection of highly deformed isomeric states in ²⁸Si, ²⁴Mg and ²⁰Ne.

11. ¹²C(¹⁹F, ²⁰Ne)¹¹B Q_m = -3.113

This reaction was studied with the use of molecular orbital theory (1988DI08).

12. ¹³C(⁹Be, 2n)²⁰Ne Q_m = 5.373

For cross sections see (1986CU02).

13. ¹⁴N(¹²C, ⁶Li)²⁰Ne Q_m = -4.181

See reaction 9.

14. ¹⁴N(¹⁴N, 2α)²⁰Ne Q_m = 7.918

For yields of 1.63 MeV γ-rays see (1982DE39).

15. ¹⁴N(²⁰Ne, ¹⁴N)²⁰Ne

Spectra were measured for E(²⁰Ne) = 150 MeV/nucleon (1992EGZZ).

16. ¹⁶O(α, γ)²⁰Ne Q_m = 4.730

Observed resonances in the yield of capture γ-rays over the range E_α = 0.8 to 10 MeV are displayed in 20.21 (in PDF or PS). For a discussion of ²⁰Ne*(11.26) [J^π = 1⁺; T = 1], to which excitation by this reaction is parity forbidden, see (1983FI02). See also (1984BU01). Total cross sections have been measured in the range E_cm = 1.7 to 2.35 MeV. Assuming that S does not vary with energy over that interval, the astrophysical factor for non-resonant capture to ²⁰Ne_g.s. is 0.26 ± 0.07 MeV · b. An estimate of 0.7 ± 0.3 MeV · b for S at 300 keV is deduced (1987HA24). A comment (1988BA26) on this work summarizes the status of theoretical descriptions of ¹⁶O(α, γ)²⁰Ne and discusses the (1987HA24) result in the light of a microscopic calculation. See also 20.21 (in PDF or PS). For other papers on astrophysical considerations see (1985CA41, 1988CA26, 1990BL1K, 1991RA1C). For earlier work, see (1987AJ02).

A microscopic description of the α + ¹⁶O system in a multicluster model is discussed in (1994DU09). An anharmonic oscillating model description is presented in (1993CSZU).

17. (a) ¹⁶O(α, p)¹⁹F Q_m = -8.114
(b) ¹⁶O(α, d)¹⁸F Q_m = -16.321 E_b = 4.730

For reaction (a) see (1990KOZG).

For reaction (b) see (1986KA36). A theoretical study of clustering in Yrast states is described in (1995KA53).

18. (a) ¹⁶O(α, α)¹⁶O E_b = 4.730
(b) ¹⁶O(α, αα)¹²C Q_m = -7.162

Excitation functions have been measured over a wide range of energies for elastically and inelastically scattered α-particles and γ-rays from the decay of ¹⁶O*(6.13, 6.92, 7.13) [see (1978AJ03, 1983AJ01)] and (1986LE23; 1.8 to 4.8 MeV; α₀), (1985JA17; 2.0 to 3.6 MeV; α₀), (1983CA1F, 1985CA09; 9.2 to 13.5 MeV; α₀), (1992LA01; 10.2 to 18 MeV; α₁) and (1979BI10, 1984RI06; 14.6 to 20.4 MeV; α₀ → α₅). See also (1983FR14, 1985ISZU) and ¹⁶O in (1993TI07).

A number of anomalies are observed: see 20.22 (in PDF or PS). K^π parameter assignments derived from this and other work are displayed in 20.20 (in PDF or PS) (1984RI07). See also (1983MI22, 1990WE14, 1992AR18). Backscattering cross section measurements and other application-related studies are reported in (1990LE06, 1991LE33, 1992DE10, 1993CH48, 1993SO19). For reaction (b) see ¹²C in (1985AJ01).

In theoretical work related to ¹⁶O(α, α)¹⁶O, studies have been reported for: optical potentials in the range E_α = 0 - 150 MeV (1993AB02, 1995MI13), phase equivalent complex potentials (1996BA26), quadrupole resonances (1993BY03), a single-folding potential model (1993LI25, 1993YA08), an R-matrix analysis of elastic cross sections in the range E_α = 2 - 9 MeV (1994SH35), the orthogonality condition model (1987SA55), Yrast structure change of ²⁰Ne (1987KA24), microscopic cluster theory (1987TA1C), core-plus-alpha states in terms of vibron models (1988CS01), distribution of α-particle strength (1988LE05), α cluster formation in the cluster-orbital shell model (1990HA38), the microscopic complex effective interaction for α - ¹⁶O (1991YA08), and the generator-coordinate description (1987RE04, 1992KR12).

19. ¹⁶O(⁶Li, d)²⁰Ne Q_m = 3.255

Deuteron groups have been observed to many states of ²⁰Ne: see 20.23 (in PDF or PS). Angular distributions have been measured for E(⁶Li) = 5.5 to 75.4 MeV: see (1978AJ03, 1983AJ01, 1984MO08). Measurements of angular diestribution at E(⁶Li) = 22 MeV provided data that were used to determine the ratios of α-particle widths in ¹⁹Ne relative to ²⁰Ne (1995MA28) and to obtain alpha spectroscopic factors for ²⁰Ne states up to E_x = 6 MeV (1996MA07). Angular correlations [(d, α₀) to ¹⁶O_g.s.] have been measured at E(⁶Li) = 60, 75, and 95 MeV (1982AR20, 1988ARZU). An experimental study of the competition between evaporation and direct transfer is described in (1995XE01). See also references cited in (1987AJ02).

In theoretical work published since the previous review, Hauser-Feshbach theory was applied to this reaction by (1987AR13), and angular distributions were analyzed with DWBA formalism by (1992RA22). See also (1994OS05).

20. ¹⁶O(⁷Li, t)²⁰Ne Q_m = 2.263

States observed in this reaction are displayed in 20.23 (in PDF or PS). Angular distributions have been measured at E(⁷Li) = 15 to 68 MeV: see (1978AJ03, 1983AJ01). See also (1986CO15). The reaction ⁷Li(¹⁶O, t)²⁰Ne was used in a lifetime measurement by (1995YU05).

Theoretical work related to this reaction includes studies on: the form of the α particle potential in direct α-transfer reactions (1986GR29, 1988GR1I), a Hauser Feshbach theory application (1987AR13), the optical potential (1989BE51), clustering phenomena and shell effects (1988RA1G), DWBA analysis (1992RA22).

21. ¹⁶O(⁹Be, ⁵He)²⁰Ne Q_m = 2.263

See (1985CU1A).

22. (a) ¹⁶O(¹²C, ⁸Be)²⁰Ne Q_m = -2.636
(b) ¹⁶O(¹²C, 2α)²⁰Ne Q_m = -2.545
(c) ¹⁶O(¹²C, α¹²C)¹²C Q_m = -7.162

Angular distributions in reaction (a) have been measured for E(¹⁶O) = 27.1 to 53.0 MeV and for E(¹²C) = 22.7 to 78 MeV [see (1978AJ03, 1983AJ01)] as well as at E(¹²C) = 109 MeV (1984MU04, 1985MU14; ²⁰Ne*(1.63, 4.25, 5.79, 7.16, 8.78, 10.26, 11.95, 12.59, 15.34, 15.87, 17.30, 21.08, 22.87); σ(θ) at several angles; EFR-DWBA analysis). See also (1988CAZV). Γ_α₀/Γ are displayed in 20.23 (in PDF or PS): see (1983AJ01, 1987AJ02) and (1983SH26). Spectroscopic factors were extracted in a direct reaction study reported by (1989OS02). Evidence for 10⁺ strength at E_x = 27.5 MeV is reported by (1988AL07). See also (1983DEZW). For discussion of ²⁸Si states reached in this reaction see (1993ES01, 1993ES03, 1993ZH21). See also the discussion of instrumentation development for ⁸Be detection reported in (1991SU15). For reaction (b) see (1978AJ03) and (1986CA19). For reaction (c) and for a discussion of ²⁴Mg states reached in this reaction see (1983SH26, 1984MU04). See also (1985BE37, 1986BE19, 1987SU03).

23. ¹⁶O(¹³C, ⁹Be)²⁰Ne Q_m = -5.918

At E(¹³C) = 105 MeV angular distributions to ²⁰Ne*(1.63, 4.25, 8.78, 11.95, 15.34, 21.0) have been studied by (1979BR03): the first four states are the 2⁺, 4⁺, 6⁺, and 8⁺ members of the 0⁺₁ band; the two higher states [J^π = 7^-, 9^-] belong to the 0^- band for which the band head is ²⁰Ne*(5.79). In addition, distributions are reported to ²⁰Ne*(12.59, 15.9, 17.3) [J^π = 6⁺, 8⁺, 8⁺] (1979BR03). See also (1985MU14). Spectroscopic factors were extracted in a direct reaction study reported by (1989OS02). For fusion cross sections see (1986PA10).

24. ¹⁶O(¹⁶O, ¹²C)²⁰Ne Q_m = -2.432

Angular distributions have been reported to a number of states of ²⁰Ne at E(¹⁶O) = 23.9 to 95.2 MeV [see (1978AJ03, 1983AJ01)] and at E(¹⁶O) = 26, 28, and 30 MeV (1986CA24). (1983ME13) have studied the quasi-elastic spectrum at E(¹⁶O) = 50, 60, 68, and 72 MeV. Measurements of the energy dependence for E(¹⁶O) = 51 - 66 MeV were performed by (1996FR09). For excitation functions see (1986CA24; ²⁰Ne*(0, 1.63)). See also (1982KO1C, 1984ME10, 1985ST1B, 1982KO1D, 1984AP03, 1984KO13).

Studies of the direct-reaction mechanism for this reaction have been carried out by (1988GA1L, 1988GA19, 1989OS02, 1990OS03). See also (1988AU03) and references cited in (1987AJ02).

25. (a) ¹⁷O(³He, ³He)¹⁷O E_b = 21.164
(b) ¹⁷O(³He, α)¹⁶O Q_m = 16.434

The excitation function for α₀ shows a resonance corresponding to ²⁰Ne*(28.): see (1978AJ03). Measurements of A_y at E(³He) = 33 MeV, have been reported for the elastic scattering [reaction (a)] (1983LE03) and for many α-groups [see ¹⁶O in (1993TI07)] (1982KA12). For the earlier work and for other channels see (1983AJ01, 1987AJ02).

26. ¹⁷O(α, n)²⁰Ne Q_m = 0.587

Neutron emission from this reaction was measured for E_α = 5.15 and 5.49 MeV by (1987SM09). Excitation functions were measured at astrophysical energies and S-factor curves were determined by (1995KU1H). See also work cited in (1978AJ03). In a recent theoretical study, the three-cluster generator coordinate method was applied to calculation of the low energy cross section by (1993DE32).

27. (a) ¹⁷O(¹¹B, ⁸Li)²⁰Ne Q_m = -6.045
(b) ¹⁷O(¹²C, ⁹Be)²⁰Ne Q_m = -5.115

At E = 115 MeV the 8⁺ state at E_x = 11.95 MeV is strongly populated in both reactions: see (1983AJ01).

28. ¹⁸O(³He, n)²⁰Ne Q_m = 13.120

Angular distributions have been measured for E(³He) = 2.8 to 18.3 MeV. States of ²⁰Ne observed in this reaction are displayed in 20.23 (in PDF or PS) of (1983AJ01). These include a state at E_x = 16.7329 ± 0.0027 MeV, Γ_cm = 2.0 ± 0.5 keV: J^π = 0⁺, T = 2. Differential cross sections were measured at E(³He) = 30 MeV by (1995FUZT).

29. ¹⁹F(p, γ)²⁰Ne Q_m = 12.844

The previous review (1987AJ02), observed that over the range E_p = 2.9 to 12.8 MeV, the γ₀ and γ₁ yields are dominated by the E1 giant resonance (Γ ≈ 6 MeV) with the γ₁ giant resonance displaced upward in energy. Strong well-correlated structures are observed with characteristic widths Γ ≈ 175 keV. Angular distributions taken over the energy range do not vary greatly with energy. They are incompatible with γ₀ and γ₁ coming from the same levels in ²⁰Ne. The 90° γ₀ yield for E_p = 3.5 to 10 MeV has been measured: the results are interpreted in terms of four primary doorway states at E_x = 16.7, 17.8, 19.1 and 20.2 MeV. See also (1985WAZV; E_p = 5.9 to 10.3 MeV; E2 strength; prelim.). See also (1986OUZZ).

More recently, polarized and unpolarized angular distributions were measured for E_p = 16.1 - 23.0 MeV (1988KU08). Data for (p, γ₁) were also presented and a doorway state calculation was discussed. Cross section and analyzing powers for (p, γ₀γ₁) were measured in the range E_p = 3.5 - 13.3 MeV by (1988WA13) in a study of the E2 strength in ²⁰Ne. See also the review of giant resonance work in (1988HA12).

The yield curve for 11.2 MeV γ-rays [from the decay of ²⁰Ne*(11.26), J^π = 1⁺, T = 1, to the ground state] displays a resonance at E_p = 4.090 ± 0.005 MeV [²⁰Ne*(16.73)]. The 11.2 MeV γ-rays are isotropic which is consistent with the presumed 0⁺ character of this lowest T = 2 state in ²⁰Ne: Γ_pΓ_γ/Γ ≈ 0.5 eV. Since Γ_p/Γ (from the elastic scattering) is ≈ 0.1, Γ_γ ≈ 5 eV. For E_p = 5.65 to 6.21 MeV, the γ₀ and γ₁ yields are not resonant but the yield of 10.6 MeV γ-rays is resonant at 5.879 ± 0.007 MeV [Γ_cm = 9.5 ± 3 keV, Γ_p₀Γ_γ/Γ ≈ 0.05 eV; Γ_γ ≈ 0.3 eV]. The 10.6 MeV γ-ray is due to the cascade decay of ²⁰Ne*(18.43), J^π = 2⁺, T = 2 via ²⁰Ne*(12.22) to the 2⁺ state at 1.63 MeV. For the upper limits to the strengths of the transitions to various states of ²⁰Ne from the 0⁺ and 2⁺ T = 2 states, see (1983AJ01). Internal pair conversion of the GDR at E_x ≈ 18 MeV was observed by (1989MOZY). Resonances observed in the capture reaction are displayed in 20.24 (in PDF or PS). For references see (1978AJ03, 1983AJ01). See also the astrophysics-related work in (1987RO25, 1988CA26). A study of absolute thick-target yields for elemental analysis at E_p = 7, 9 MeV is reported in (1987RA23).

30. (a) ¹⁹F(p, p')¹⁹F E_b = 12.844
(b) ¹⁹F(p, d)¹⁸F Q_m = -8.207

The elastic scattering has been studied in the range E_p = 0.5 to 7.5 MeV and 24.9 to 46.3 MeV [see (1978AJ03)] and at E_p = 1.5 to 3.5 MeV (1985OU01, 1986OUZZ, 1986OU01). See also the measurements for E_p = 0.85 - 1.01 MeV at θ_lab = 165° by (1989KN01), and the work reported in (1994CO12) in which a ¹⁹F radioactive beam was used in scattering off polyethelyne targets. The observed anomalies are displayed in 20.25 (in PDF or PS).

Resonances for inelastic scattering [p₁ and p₂] are listed in 20.26 (in PDF or PS). In general the resonances observed are identical with those reported from other ¹⁹F + p reactions, although the relative intensities differ greatly. Cross sections for production of 110 and 197 keV γ-rays are reported for E_p = 0.5 to 4.3 MeV by (1986CHYY). See also (1983LE28; astrophysics) and (1986BA88). For reaction (b) see (1986KA1U; applied) and ¹⁸F.

31. ¹⁹F(p, n)¹⁹Ne Q_m = -4.020 E_b = 12.844

Observed resonances are displayed in 20.30 (in PDF or PS) of (1978AJ03). See also (1984BA1R, 1985CA41). The transfer polarization coefficient for E_p = 120, 160 MeV at θ = 0° was measured by (1990HUZY). Total cross sections for production of ¹⁹Ne measured by the activation method are reported by (1990WA10).

32. ¹⁹F(p, α)¹⁶O Q_m = 8.114 E_b = 12.844

Many resonances occur in this reaction. They are displayed in 20.27 (in PDF or PS), 20.29 (in PDF or PS), and 20.28 (in PDF or PS) depending on whether they are observed in the α₀ yield [20.23], in the α₁ [or α_π] yield to ¹⁶O*(6.05) [20.24] or in the α₂, α₃, and α₄ yields [or in the yield of the γ-rays from ¹⁶O*(6.13, 6.92, 7.12) [20.25]]. See also Tables 2 and 3 in (1993DA23) which list a number of new resonances for E_p = 0.3 - 3.0 MeV. Resonances for α₀ and α₁ are required to have even J, even π or odd J, odd π, while the α₂, α₃, and α₄ resonances are all odd-even or even-odd, with the exception of the T = 2 resonance.

Listings of the earlier yield studies are given in (1972AJ02, 1978AJ03, 1983AJ01). A detailed discussion of the evidence leading to many of the J^π assignments is given in (1959AJ76). For values of θ² see 20.28 (in PDF or PS) in (1978AJ03). Other measurements are reported by (1985OU01; 1.5 to 2.1 MeV; α₀ → α₃) and (1984IN04; 4.15 to 13 MeV; α₀ → α₅). In the latter work there are no marked correlations between the different channels.

Longitudinally and transversely polarized protons with E_p ≈ 0.67 MeV have been used to study ²⁰Ne*(13.48) [J^π = 1⁺; T = 1] via a parity- (and isospin-) forbidden α-transition. The state is not excited. The upper limits for the process, and their significance in the determination of f_π, the weak pion-nucleon coupling constant, are discussed by (1983KN01, 1986KN1C, 1990KN01). See also (1983AJ01, 1984KN1A).

Internal pair conversion for ¹⁹F(p, α_π) of the 18 MeV GDR in ²⁰Ne was studied by (1989MOZY) at E_p = 5.2 MeV.

A DWBA analysis for energies below the Coulomb barrier is used to determine the astrophysical S-factor in (1991HE16). See also (1993YA18).

Application-related work is reported in (1987EV01, 1989MC04, 1989MC03, 1989TA1N). See also the earlier work cited in (1987AJ02).

33. ¹⁹F(d, n)²⁰Ne Q_m = 10.620

Levels of ²⁰Ne derived from this reaction are displayed in 20.31 (in PDF or PS) in (1972AJ02) and 20.34 (in PDF or PS) in (1978AJ03). See also (1983LIZW).

34. ¹⁹F(³He, d)²⁰Ne Q_m = 7.350

Levels of ²⁰Ne observed in this reaction are displayed in 20.35 (in PDF or PS) in (1978AJ03) and 20.32 (in PDF or PS) in (1983AJ01). Deuteron angular distributions have been studied at E(³He) = 9.5 to 21 MeV: see (1978AJ03). A more recent measurement of differential cross sections at E(³He) = 22.3 MeV and DWBA analysis was reported by (1994ARZY).

The excitation energy difference (ΔE_x) between the 1⁺ and 1^-, T = 1 states ²⁰Ne*(11.26, 11.27) is 11.1 ± 0.7 keV (1983FI02). Γ_γ/Γ_α = 0.88 ± 0.05 for ²⁰Ne*(12.22) [2⁺; T = 1] (1984CA08). Using (2J + 1)Γ_αΓ_γ/Γ = 1.41 ± 0.23 eV (1980FI01), Γ_α = 0.32 ± 0.06 eV for ²⁰Ne*(12.22) (1984CA08). The value of Γ_γ/Γ of ²⁰Ne*(12.22) implies B(M1) = 0.07 W.u. for the transition from ²⁰Ne*(18.43) [2⁺; T = 2]. This is much weaker than other isovector M1 transitions in ²⁰Ne and a factor of five lower than predicted by shell model calculations: see (1984CA08).

In recent work at E(³He) = 25 MeV, differential cross sections were measured (1994VE04) for ²⁰Ne levels at E_x = 0, 1.634 MeV. DWBA calculations were carried out and absolute values of C²S were extracted and compared with shell model calculations.

35. ¹⁹F(α, t)²⁰Ne Q_m = -6.970

Angular distributions have been measured at E_α = 18.5 and 28.5 MeV: see (1978AJ03, 1983AJ01). The double differential cross section was measured at E_α = 30.3 MeV in a study of the reaction mechanism involving excitation of the 0⁺, 2⁺ and 4⁺ states at E_x = 0, 1.63, 4.25 MeV (1995IG03).

36. ¹⁹F(⁷Li, ⁶He)²⁰Ne Q_m = 2.869

Angular distributions have been studied at E(⁷Li) = 34 MeV to a number of states of ²⁰Ne. C²S values are consistent with those reported in the (d, n) and (³He, d) reactions: see (1978AJ03).

37. ²⁰F(β^-)²⁰Ne Q_m = 7.025

The decay is primarily to ²⁰Ne*(1.63) with a half-life of 11.163 ± 0.008 s (1992WA04): see reaction 1 in ²⁰F. Besides the principal decay to ²⁰Ne*(1.63) [log f₀t = 4.97], ²⁰F also decays to ²⁰Ne*(4.97) [J^π = 2^-] with a branching ratio of (0.0082 ± 0.0006)% (1987AL06) [log f₀t = 7.20 ± 0.03; D.E.Alburger and E.K.Warburton, see (1987AJ02)]. The upper limit for the ground-state decay is 0.001% [log f₀t > 10.5]. For other values and earlier references see 20.36 (in PDF or PS) in (1978AJ03). The energy of the γ-ray from ²⁰Ne*(1.63) is 1633.602 ± 0.015 keV. E_γ for the 4.97 → 1.63 transition is 3332.54 ± 0.19 keV which gives E_x = 4966.51 ± 0.20 keV based on E_x = 1633.674 ± 0.015 keV for the first excited state. The shape of the β-spectrum is in good agreement with the predictions of CVC (1983AJ01, 1987AJ02, 1989HE11). β-γ angular correlations reported by (1988RO10) are close to the expectations based on CVC theory. For earlier work see (1978AJ03, 1983AJ01, 1987AJ02). The ²⁰F(β^-)²⁰Ne decay is thought to play a part in heavy element nucleosynthesis (1988AP1A). See also (1989MA1U, 1989TA26).

38. (a) ²⁰Ne(γ, n)¹⁹Ne Q_m = -16.864
(b) ²⁰Ne(γ, nn)¹⁸Ne Q_m = -28.491
(c) ²⁰Ne(γ, α)¹⁶O Q_m = -4.730

The photoneutron cross section (bremsstrahlung photons) shows peaks at E_x = 17.78 ± 0.05, 19.00 ± 0.05, 20.15 ± 0.15 [main peak of the GDR], 22.6 ± 0.3, 24.9 ± 0.5 and 27.5 MeV [the latter three states are broad]: the integrated cross section to 28.5 MeV is 58 ± 6 MeV · mb [exhausting ≈ 20% of the dipole sum]. The cross section for (γ, tot) using monoenergetic photons shows a structure at 18 MeV and some fluctuations atop the broad giant dipole resonance, σ_max ≈ 7 mb. The double photoneutron cross section, σ(γ, 2n), is dominated by a single peak at E_γ ≈ 20.5 MeV, σ_max ≈ 1.1 mb. For references see (1978AJ03, 1983AJ01) and see the atlas of photoneutron cross sections with monoenergetic photons (1988DI02). The significance of reaction (c) to astrophysics is discussed by (1982SA1A, 1984FO1A).

39. ²⁰Ne(γ, γ)²⁰Ne

The first 1⁺; T = 1 state in ²⁰Ne is measured at E_x = 11262.3 ± 1.9 keV. The branchings to ²⁰Ne*(0, 1.63) are (84 ± 5) and (16 ± 5)%, respectively (1983BE19). See also (1984BE26).

40. (a) ²⁰Ne(e, e')²⁰Ne
(b) ²⁰Ne(e, e'p)¹⁹F Q_m = -12.844
(c) ²⁰Ne(e, e'α)¹⁶O Q_m = -4.730

The ²⁰Ne charge radius, < r² >_1/2 = 3.004 ± 0.025 fm. Form factors for many excited states of ²⁰Ne with E_x < 8 MeV have been reported: see (1978AJ03).

At E_e = 39 and 56 MeV, the 180° inelastic scattering is dominated by the transition to a J^π = 1⁺, T = 1 state at E_x = 11.22 ± 0.05 MeV with Γ_γ₀ = 11.2^+2.1_-1.8 eV. A subsidiary peak is observed corresponding to a state 0.35 ± 0.03 MeV higher [if J^π = 1⁺ or 2⁺, Γ_γ₀ = 0.65 ± 0.18 or 0.40 ± 0.13 eV]. A number of small peaks are also reported corresponding to E_x ≈ 12.0, 12.9, 13.9, 15.8, 16.9, 18.0 and 19.0 MeV. Prominent electric dipole peaks are reported at E_x = 17.7, 19.1, 20.2, and 23 MeV, in addition to weaker structures between 12.5 and 15 MeV; and prominent electric quadrupole peaks are observed at E_x = 13.0, 13.7, 14.5, 15.0, 15.4 and 16.2 MeV and there is broad quadrupole excitation between 16 and 25 MeV. The GDR cross section integrated from 11 to 25 MeV contains about 65% of the dipole EWSR while over 90% of the isoscalar quadrupole EWSR is exhausted by the strength in the region 10 - 25 MeV.

For 11 < E_x < 24 MeV only two isovector M2 transitions appear: these are to ²⁰Ne*(11.62, 12.10) with B(M2, k)(↑) = 64 ± 13 and 56 ± 13 μ²_Nfm² [orbital contributions are non-negligible]. The M1 transition to ²⁰Ne*(11.26) is also observed but that to ²⁰Ne*(13.48) is not: it is < 0.2 μ²_N (1985RA08). For reaction (b) see (1978AJ03).

Reaction (c) has been studied in order to obtain the (γ, α₀) cross section in the giant resonance region: the cross section at 90° for E_x = 15 to 24 MeV is dominated by an E1 resonance [1^-; T = 1, with an admixture of T = 0 which permits the α₀ decay] at E_x = 20 MeV; lesser E1 structures are reported at E_x = 16.7, 17.1, 21 and 22 MeV. A relatively strong 2⁺; T = 0 resonance appears at E_x = 18.5 MeV, and evidence is reported for increasing E2 strength below 16 MeV. For references to the early work see (1978AJ03, 1987AJ02). For more recent work see the reviews on nuclear dipole excitations (1987BE1G) and status of the shell model (1988BR1P). Other more recent theoretical work includes studies of large basis space effects in electron scattering form factors (1990AM01), correlated charge form factors and densities for s-d shell nuclei (1990MA63), electron scattering multipoles for symplectic shell model application (1992RO08), mass number dependence of the difference between electron- and muon-scattering charge radii (1989AN12), electron scattering from ²⁰Ne in a microscopic boson model (1988KU07, 1988KU22, 1988KU17), and studies of (e, e'γ) reactions and electromagnetic currents in rotational nuclei (1990GA09). See also (1988BR1D, 1988ZH1F, 1990MO1J).

41. (a) ²⁰Ne(π^±, π^±')²⁰Ne
(b) ²⁰Ne(π^±, X)

Inelastic pion scattering experiments at T_π = 120 MeV and 180 MeV indicate a broad 2⁺ member of the K^π = 0⁺₄ band in ²⁰Ne (1989BU14, 1995BU01). They report E_x = 9.00 ± 0.18 MeV, Γ = 0.8 MeV, B(E2(↑)) = 40.9 ± 2.0 e²fm⁴. Several other states in the first four K^π = 0⁺ bands were studied by (1995BU01). See 20.30 (in PDF or PS).

For reaction (b), spectra have been measured and analyzed for initial pion momenta of 6.2 GeV/c (1991AM1B, 1992KI31).

42. ²⁰Ne(n, n')²⁰Ne

An evaluation of neutron-induced reaction cross sections of ²⁰Ne for E_n = 1 - 30 MeV is presented in (1991RE10). See also (1993DE32) and earlier work cited in (1978AJ03).

43. (a) ²⁰Ne(p, p')²⁰Ne
(b) ²⁰Ne(p, p'α)¹⁶O Q_m = -4.730

Angular distributions of elastically scattered protons and of a number of inelastic groups have been measured for E_p = 2.15 to 65 MeV [see (1978AJ03, 1983AJ01)] and at E_p = 0.8 GeV (1984BL14, 1988BL13; to ²⁰Ne*(0, 1.63, 4.25, 8.7) (u); also A_y). The latter work confirms the large hexadecapole deformation of ²⁰Ne. At E_p = 201 MeV, probable 1⁺ states at E_x = 11.25 ± 0.01, 13.51 ± 0.03 and 15.72 ± 0.05 MeV are reported by (1987WI03): There does not appear to be any quenching of the M1 strength. In addition 2^- states are observed at 11.58 and 12.08 MeV with B(M2) = 64 ± 13 and 56 ± 13 μ²_N as is a state of unknown J^π at E_x ≈ 17 MeV (1987WI03). See also (1988CR1B), the measurements at E_p = 6.4 - 7.7 MeV (1992WI13), measurements at E_p = 60 - 180 MeV (1993PLZY), and the earlier work cited in (1978AJ03). For reaction (b) see (1984CA09, E_p = 101.5 MeV), (1992WI13, E_p = 6.4 - 7.7 MeV), and the earlier experimental and theoretical work cited in (1987AJ02). See also (1993MU28).

Theoretical work reported since the previous compilation includes relativistic DWBA calculations on inelastic scattering at E_p = 200 - 800 MeV (1988JO02), a large-basis-space microscopic-model analysis of 800-MeV inelastic scattering (1991AM1A), studies with a coalescence model of hypernuclear formation and mesonic atom production (1989WA14) in high energy collisions (1988WA16, 1989SA58), analysis of 800-MeV inelastic scattering with the Dirac formalism (1990PH01, 1990PH02, 1992DE31). See also the microscopic three-cluster study of 21-nucleon systems presented in (1993DE32).

44. ²⁰Ne(p, π^±)

Experimental data on multiplicity, correlations, and inclusive spectra of mesons and other particles produced in p + ²⁰Ne reactions at E_p = 300 GeV are presented in (1992YU1A) and compared with model predictions.

45. ²⁰Ne(p-bar, p-bar)²⁰Ne

For references to work on antiproton interactions see 20.16 (in PDF or PS) and "GENERAL section" here.

46. (a) ²⁰Ne(d, d')²⁰Ne
(b) ²⁰Ne(t, t')²⁰Ne

Angular distributions of deuterons have been reported at E_d = 10.0 to 52 MeV [see (1978AJ03, 1983AJ01)] and at E_d = 52 MeV (1987NU01). Differential cross sections for elastic and inelastic scattering of tritons (reaction (b)) were measured at E_t = 33.4 MeV by (1992HA12) and analyzed by the coupled channels method. Potential parameters, deformation lengths and multipole moments were deduced. See also the calculations for these data described in (1992HA18) in which spin, parity and band assignments are discussed. The calculations suggest the assignments of K^π = 2^-, 2^- and 0^- respectively to the J^π = 2^-, 3^-, 3^- states at E_x = 4.97, 5.62 and 5.79 MeV. See also (1978AJ03, 1987AJ02).

47. ²⁰Ne(³He, ³He')²⁰Ne

Angular distributions have been measured at E(³He) = 10 to 35 MeV and at 68 MeV: see (1978AJ03). See references cited in (1978AJ03). More recently differential cross section for elastic and inelastic scattering of ³He were measured at E(³He) = 33.4 MeV by (1992HA12) and analyzed by the coupled channels method. Comparisons were made with triton scattering. Calculations for these data were described in (1992HA18) in which spin, parity and band assignments are discussed. Elastic scattering measurements at E(³He) = 30 and 45 MeV are described in (1992NAZQ).

48. (a) ²⁰Ne(α, α')²⁰Ne
(b) ²⁰Ne(α, αα)¹⁶O Q_m = -4.730

Angular distributions have been measured at E_α = 3.8 - 155 MeV [see references cited in (1978AJ03)]. More recently measurements were made at E_α = 54.1 MeV (1987AB03), E_α = 50 MeV (1991FR02) and at E_α = 3.8 - 11 MeV (1991AB05). Inelastic cross sections were measured at E_α = 5.6 - 11.0 MeV (1992DA10), E_α = 50 MeV (1991FR02), and E_α = 50.5 MeV (1987BU27).

For reaction (b) see references cited in (1983AJ01, 1987AJ02) and the measurements at E_α = 155 MeV of cross sections and decay branching ratios for several excited states of ²⁰Ne up to the giant quadrupole resonance by (1987SU09).

Theoretical studies related to these reactions include: α + ²⁰Ne structures of ²⁴Mg in a microscopic three-cluster (α + α + ¹⁶O) model (1987DE40), distributions of α-particle strengths in light nuclei (1988LE05), target clustering and exchange effects in internuclear interactions (1988LE06), stationary-state currents in nuclear reactions (1988MA30), a DWIA analysis of ²⁰Ne(α, 2α)¹⁶O at E_α = 140 MeV (1988SH05), distortion effects in a microscopic ¹⁶O + 2α description of ²⁴Mg (1989DE32), evidence for a parity dependence in the α + ²⁰Ne interactions (1989MI12), an l-dependent representation of a Majorana potential (1990CO38), a strong-absorption model analysis of α scattering (1992RA21), a calculation of quasimolecular states in ²⁰Ne(α, α) (1992GR15), optical model analysis of ²⁰Ne(α, α) at E_α = 22.9 MeV (1993AOZZ).

49. ²⁰Ne(⁷Li, ⁷Li')²⁰Ne

Angular distributions have been studied at E(⁷Li) = 36, 68, and 89 MeV: see (1983AJ01).

50. ²⁰Ne(⁹Be, ⁹Be')²⁰Ne

For pion production see (1985FR13).

51. (a) ²⁰Ne(¹⁰B, ¹⁰B)²⁰Ne
(b) ²⁰Ne(¹¹B, ¹¹B)²⁰Ne

Elastic angular distributions have been measured at E(¹⁰B) = 65.9 and E(¹¹B) = 115 MeV: see (1983AJ01).

52. (a) ²⁰Ne(¹²C, ¹²C')²⁰Ne
(b) ²⁰Ne(¹²C, α⁸Be)²⁰Ne Q_m = -7.366

Elastic angular distributions have been obtained at E(¹²C) = 22.2 to 77.4 MeV and at E(²⁰Ne) = 65.9, 74 and 75.2 MeV [see (1978AJ03, 1983AJ01)] as well as at E(²⁰Ne) = 72.6, 74.0 and 75.2 MeV (1982SH29). Elastic and inelastic scattering differential cross sections at E(²⁰Ne) = 390 MeV were measured by (1993BO28).

For yield, fusion, total reaction cross section and fragmentation studies see the references cited in (1987AJ02). More recently fragmentation studies at E(²⁰Ne) = 540 - 1096 MeV/nucleon were reported by (1990WE14) and at E(²⁰Ne) = 400, 800 MeV/nucleon by (1988DU01). See also (1987AN20, 1994FU01). For pion production and for reaction (b) see references cited in (1987AJ02).

Theoretical studies carried out since the previous compilation include: resonances, heavy-ion radioactivity and new predictions for medium mass collective systems (1989CI1C), cascade model study of Λ particle productions in central collisions of light nuclei (1988IW02), comparison of quantized ATDHF and GCM theory applied to the ¹²C + ²⁰Ne system (1990SL01).

53. ²⁰Ne(¹⁶O, ¹⁶O')²⁰Ne

Angular distributions have been studied at E(²⁰Ne) = 50 and 94.8 MeV involving ¹⁶O_g.s. and ²⁰Ne*(0, 1.63, 4.25) [see (1983AJ01)], at E(¹⁶O) = 25.6 to 44.5 MeV (elastic; also to ²⁰Ne*(1.63) at 31.3, 33.3 and 44.5 MeV)) and at E(²⁰Ne) = 66.8, 115, 137 and 156 MeV (elastic) [see (1987AJ02) for references]. Yield and fusion cross section measurements have also been reported in several references cited in (1987AJ02). Excitation functions at θ_cm = 90° for E_cm = 21.5 - 31.2 MeV were measured by (1988HE06) and at θ_lab = 13° for E_cm = 22.8 to 38.6 MeV by (1989SA14). Measurements at projectile energies of 3.6 MeV/nucleon are reported in (1987AN20), and at 4.2 and 4.5 GeV/nucleon by (1988BO46, 1988BE2A).

Theoretical studies related to this reaction reported since the previous review include: calculation within the framework of the cascade model (1988IW02), molecular orbital theory for elastic and inelastic scattering (1989HE1I), derivation of the parity-independent interaction for ¹⁶O + ²⁰Ne (1989GA1L), optical model analysis of resonant structure in ¹⁶O + ²⁰Ne (1991GA14), and local representation of a deep parity- and L-dependent ¹⁶O + ²⁰Ne potential (1993AI02).

54. ²⁰Ne(²⁰Ne, ²⁰Ne')²⁰Ne

Elastic angular distributions are reported at E(²⁰Ne) = 68, 117, 140, and 156 MeV (1983SH25). For yield and fusion measurements see references cited in (1983AJ01, 1987AJ02). High-spin shape isomers for sd-shell nuclei were studied at E_cm near 1.6 times the Coulomb barrier for ²⁰Ne + ²⁰Ne by (1993BAZZ). Studies of the average number of interacting protons in ²⁰Ne + ²⁰Ne collisions of 36 GeV/nucleon were reported by (1987AN20).

Theoretical work related to the reaction includes: a study of mesonic atom production by a coalescence model (1989WA14), a formulation of the mesonic atom production probability with a coalescence model (1989SA58), hypernucleus production by heavy ions by a coalescence process (1989BA92, 1989WA14, 1989BA93).

55. (a) ²⁰Ne(²⁴Mg, ²⁴Mg')²⁰Ne
(b) ²⁰Ne(²⁶Mg, ²⁶Mg')²⁰Ne

Elastic angular distributions for reaction (a) have been measured at E(²⁰Ne) = 50, 60, 80, 90, and 100 MeV [see (1983AJ01)] at 40 MeV (1983NA04; S_α for the system ²⁰Ne + ²⁴Mg = 0.08 ± 0.02) and at E_lab = 55, 80 and 160 MeV/nucleon (1987BE38). For yield and fusion cross sections for reactions (a) and (b) see references cited in (1987AJ02). See also the review of high energy gamma production in heavy ion collisions (1989NI1D).

56. ²⁰Ne(²⁷Al, ²⁷Al')²⁰Ne

Elastic angular distributions are reported at E(²⁰Ne) = 55.7, 63, 125, and 151 MeV (1983NG01). For yield, fusion and evaporation residue studies see references cited in (1987AJ02) and the study at E(²⁰Ne) = 217, 194 and 384 MeV (1988GR12, 1989BA17, 1990BA18). A search for incomplete deep inelastic collisions at E(²⁰Ne) = 216 MeV is reported by (1988ZH12). Neutral pion production was studied at E(²⁰Ne) = 4 GeV by (1988JU02, 1989FO07, 1989FO1G). A description of those data by the cooperative model is discussed in (1989GH01). See also the calculation of total reaction cross sections presented in (1988JO02).

57. (a) ²⁰Ne(²⁸Si, ²⁸Si')²⁰Ne
(b) ²⁰Ne(²⁹Si, ²⁹Si')²⁰Ne

See (1983DU13).

58. ²⁰Ne(⁴⁰Ca, ⁴⁰Ca')²⁰Ne

Angular distributions have been studied at E(²⁰Ne) = 44.1 to 70.4 MeV and at 151 MeV: see (1983AJ01). For an evaporation residue study see (1982MO15). For yield and fusion measurements see (1983AJ01). The breakup of ²⁰Ne at E(²⁰Ne) = 92, 149 and 213 MeV involves ²⁰Ne*(5.79, 6.73, 7.16, 8.78, 10.26, 11.95) (1986SH30).

See also the references cited in (1987AJ02) and see the Monte Carlo simulation method calculation for nuclear transfer (1988CH28), and the study of alpha clustering and shell effects related to this reaction (1989PU1C).

59. ²⁰Na(β⁺)²⁰Ne Q_m = 13.887

²⁰Na has a half-life of 447.9 ± 2.3 ms: see reaction 1 in ²⁰Na. It decays to a number of states of ²⁰Ne, principally ²⁰Ne*(1.63): see 20.31 (in PDF or PS). The ratio of the mirror decays ²⁰Na(β⁺)²⁰Ne*(1.63) and ²⁰F(β^-)²⁰Ne*(1.63), (ft)⁺/(ft)^- = 1.03 ± 0.02. β - γ correlation measurements, as in the decay of ²⁰F, lead to an upper limit for the second-class contribution to the correlation which is consistent with zero: see (1983AJ01). A more recent measurement (1988RO10) concluded that the β - γ angular correlations in A = 20 are close to and may be in agreement with conserved vector current theory. β - ν - α triple correlation coefficient measurements for the transitions via the α-unstable 2⁺ states shown in 20.31 (in PDF or PS) lead to values of the isospin mixing amplitudes [and to a determination of the vector weak coupling constant] (1983CL01, 1989CL02). See also references cited in (1987AJ02) and the measurements of (1992KUZO, 1992KUZQ).

60. ²¹Ne(e, e'n)²⁰Ne Q_m = -6.761

A general expression of the polarized spectral function for the (e, e'n) transitions is used by (1994CA27) to model this reaction.

61. ²¹Ne(p, d)²⁰Ne Q_m = -4.537

See (1978AJ03).

62. ²¹Ne(d, t)²⁰Ne Q_m = -0.504

The T = 1 states observed in this reaction, and the analog states observed in ²⁰F in the (d, ³He) reaction, are displayed in 20.16 (in PDF or PS of (1978AJ03). T = 0 states are presented in 20.38 (in PDF or PS) of 1978AJ03).

63. ²²Ne(p, t)²⁰Ne Q_m = -8.643

Angular distributions have been reported at E_p = 26.9 to 43.7 MeV: see (1978AJ03, 1983AJ01). The angular distributions of the tritons to the ground state of ²⁰Ne and to the first 0⁺, T = 2 state [E_x = 16.7329 ± 0.0027 MeV] have been fitted by L = 0 and the tritons to ²⁰Ne*(18.4) by L = 2. The latter is the first 2⁺, T = 2 state. The 0⁺, T = 2 state [²⁰Ne*(16.73)] decays by α₀[(6 ± 5)%], α₁ + α₂[(35 ± 12)%], α₃ + α₄[(29 ± 12)%], p₀₊ p₁₊ p₂[(14 ± 9)%] and p₃₊ p₄₊ p₅[(13 ± 8)%] [measured branching ratios in percent are given in the brackets] to the final states in ¹⁶O and ¹⁹F. See (1978AJ03) for references and additional information.

64. ²³Na(p, α)²⁰Ne Q_m = 2.377

Angular distributions have been measured at E_p = 10.0 and 45.5 MeV: see (1972AJ02). High resolution measurement at E_p = 1.08 - 4.15 MeV were carried out in a study of 94 resonances in ²⁴Mg by (1987VA24) at E_p = 6.25 - 6.55 MeV. A study of ²⁴Mg resonances excited by protons in the range E_p = 6.25 - 6.55 MeV is described in (1990MI24, 1991MI24). Detailed-balance tests of time reversal invariance are reported in (1994DR01, 1993MI19, 1993MI25). Parity nonconservation experiments are discussed in (1995MI28). See also (1987PA06, 1989KA06) which describe analyzing power measurements for this reaction. Measurements of the cross section at E_p ≤ 350 keV were carried out by (1989GO1N). Astrophysical implications are discussed. See also references to earlier work cited in (1987AJ02).

65. ²³Na(³He, ⁶Li)²⁰Ne Q_m = -1.642

See (1978AJ03).

66. ²⁴Mg(γ, α)²⁰Ne Q_m = -9.316

Cross sections for this reaction were calculated by (1987KA30) in a study of molecular structure of highly-excited states.

67. ²⁴Mg(n, nα)²⁰Ne Q_m = -9.316

Production cross sections for ²⁰Ne were measured at E_n = 5.20, 7.00, 16.20 and 19.05 MeV (1990LA09). Cross sections were calculated with preequilibrium emission and constant-temperature evaporation models by (1993KH09).

68. ²⁴Mg(p, pα)²⁰Ne Q_m = -9.316

See (1984CA09). See also 1978AJ03).

69. ²⁴Mg(d, ⁶Li)²⁰Ne Q_m = -7.841

Angular distributions have been studied to many states of ²⁰Ne at E_d = 28 to 80 MeV [see (1978AJ03, 1983AJ01)] and at E_d = 54.2 MeV (1984UM04; to ²⁰Ne*(0, 1.63, 4.25, 5.62)). 20.35 (in PDF or PS) in (1983AJ01) displays the observed states and S_α obtained from several analyses. For newer values of S_α see (1984UM04, 1986OE01). See also (1984PA18, 1986PAZJ). Measurements at several different incident energies were reported by (1988RA27, 1988RA20). Data were analyzed with finite-range DWBA calculations, and spectroscopic factors were obtained with different potentials. Comparisons with spectroscopic factors from ²⁴Mg(³He, ⁷Be)²⁰Ne were made.

70. ²⁴Mg(³He, ⁷Be)²⁰Ne Q_m = -7.730

Angular distributions have been studied at E(³He) = 25.5 and 70 MeV: see (1978AJ03). See also (1983AJ01) and (1986RA15). Measurements at E(³He) = 41 MeV were reported by (1988RA20, 1988RA27). Data were analyzed with finite-range DWBA calculations and spectroscopic factors were obtained with different potentials. Comparisons with spectroscopic factors from ²⁴Mg(d, ⁶Li)²⁰Ne were made.

71. ²⁴Mg(α, ⁸Be)²⁰Ne Q_m = -9.407

See (1983AJ01).

72. ²⁴Mg(¹²C, ¹⁶O)²⁰Ne Q_m = -2.154

The angular distribution for the ground state transition has been measured at E(¹²C) = 40 MeV (1982LI16) and at E_cm = 25.2 MeV (1990LE12). Coupled-channels calculations were used to study the back angle anomaly. The backward angle yield in the inverse reaction was studied at E(²⁴Mg) = 90 - 126 MeV by (1990GL01). See also (1983AJ01, 1989OB1C).

73. ²⁴Mg(¹⁶O, ²⁰Ne)²⁰Ne Q_m = -4.586

Excitation functions were measured at θ_cm = 90°, E_cm = 25 - 34 MeV by (1989LE19). Data were compared with calculations involving the coupling to higher orders between elastic and α-transfer channels. Differential cross sections were measured at E(¹⁶O) = 71.4 MeV by (1995FUZW). The effect of the dynamic α-transfer polarization potential is discussed in (1989FI03).

74. ²⁸Si(α, ¹²C)²⁰Ne Q_m = -12.026

See (1983AJ01).

75. ²⁸Si(¹⁶O, ²⁴Mg)²⁰Ne Q_m = -5.255

This reaction was studied at E_cm = 31.57 MeV by (1989PO1J).