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9B (1988AJ01)
(See Energy Level Diagrams for 9B)
GENERAL: See also (1984AJ01) and Table 9.9 [Table of Energy Levels] (in PDF or PS).
Model calculations: (1983SH38, 1987VOZU).
Special states: (1983AU1B, 1983FE07, 1983GO28, 1984KO40, 1985PO18, 1985PO19, 1985SH24, 1986AN07, 1987BA54, 1987VOZU).
Complex reactions involving 9B: (1985PO18, 1985PO19, 1987AR19, 1987PO03).
Reactions involving pions: (1985PN01).
Hypernuclei: (1982KA1D, 1983KO1D, 1983SH38, 1983SH1E, 1984ZH1B, 1985AH1A, 1985PN01, 1986DA1B, 1986KO1A, 1987BO1L, 1987MI38, 1987PO1H).
Other topics: (1985AN28, 1985SH24).
Ground state of 9B: (1983ANZQ, 1983AU1B, 1985AN28).
| 1. (a) 6Li(3He, γ)9B | Qm = 16.601 | |
| (b) 6Li(3He, n)8B | Qm = -1.975 | Eb = 16.601 |
| (c) 6Li(3He, p)8Be | Qm = 16.7863 | |
| (d) 6Li(3He, d)7Be | Qm = 0.112 | |
| (e) 6Li(3He, t)6Be | Qm = -4.307 | |
| (f) 6Li(3He, 3He)6Li | ||
| (g) 6Li(3He, α)5Li | Qm = 14.91 |
The 90° yields of γ0 and of γ to 9B*(2.36) (reaction (a)) have been measured for E(3He) = 0.6 to 1.2 MeV [as have the 2α-particles from the decay of 8Be*(16.6) (reaction (c))]: they are reported to show a resonance at E(3He) = 765 ± 5 keV [9B*(17.111)], attributed to 9B*(17.076) [T = 3/2]. The total cross section for reaction (b) increases monotonically from threshold to ≈ 7 mb at 3.8 MeV. It then decreases monotonically from E(3He) = 5.5 to 7.6 MeV and also from 8.9 to 26.5 MeV: see (1979AJ01, 1984AJ01), and 8B.
Absolute cross sections for protons (reaction (c)) to 8Be*(0, 2.9, 16.6, 16.9) as well as for the continuum protons have been measured for E(3He) = 0.5 to 1.85 MeV. Reaction rate parameters, < σν >, have been calculated for kT = 0.01 to 10.0 MeV. Excitation functions for p0 and p1 have been measured for E(3He) = 0.9 to 17 MeV, and polarization measurements are reported at E(3He) = 14 MeV. Resonances are observed at E(3He) = 1.6 and 3.0 MeV [Γ = 0.25 and 1.5 MeV]: see (1974AJ01, 1979AJ01), and 8Be. Polarization measurements are also reported at E(pol. 6Li) = 21 MeV (VAP; p0). In the range E(3He) = 0.7 to 2.0 MeV, a resonance in the excitation function for deuterons (reaction (d)) is reported corresponding to 9B*(17.6). Polarization measurements at E(pol. 3He) = 33.3 MeV for the d0 and d1 groups are reported. Excitation functions for t0 (reaction (e)) have been measured for E(3He) = 10 to 16 and 23.3 to 25.4 MeV: see (1974AJ01). Polarization measurements are reported at E(pol. 3He) = 33.3 MeV for the t0 group as well as for the 3He ions to 6Li*(0, 2.19) (reaction (f)). The elastic scattering has also been studied for E(3He) = 0.7 to 2.0 MeV. The α-α coincidences (5Lig.s. decay) (reaction (g)) have been measured for E(3He) = 1.4 to 1.8 MeV: a resonance is observed at 1.57 ± 0.02 MeV [9B*(17.63)], Γ = 70 ± 20 keV. Polarization measurements of the α-particles to 5Li*(0, 16.7) are reported at E(pol. 3He) = 33.3 MeV. For a study of the (3He, pα)4He reaction at 3.5, 4.4 and 5.5 MeV see (1987ZA07). See (1979AJ01, 1984AJ01) for references.
| 2. 6Li(α, n)9B | Qm = -3.977 |
At Eα = 28 and 32 MeV angular distributions have been measured to 9B*(0, 2.36) (1985GUZQ; prelim.). See also (1974AJ01).
| 3. 6Li(6Li, t)9B | Qm = 0.806 |
Angular distributions of the t0 group have been measured for E(6Li) = 4.0 to 5.5 MeV and at 7.35 and 9.0 MeV. No evidence was observed for a group corresponding to 9B*(1.6): see (1974AJ01).
| 4. 7Li(3He, n)9B | Qm = 9.351 |
For E(3He) to 12.5 MeV this reaction populates 9B*(0, (1.6), 2.4, 2.8, (7.0)), and states at Ex = 4.8 ± 0.1 MeV [1.0 ± 0.2 MeV], 12.06 ± 0.06 [0.8 ± 0.2], 14.01 ± 0.07 [0.39 ± 0.11], 14.657 ± 0.005 (based on Qm) [< 0.045], 16.024 ± 0.025 [0.180 ± 0.016], 17.19 and 17.63 MeV [Γ in brackets]: see (1974AJ01). 9B*(14.66) is the first T = 3/2 state in 9B. Its decay properties are displayed in Table 9.3 (in PDF or PS) and compared with those of 9Be*(14.40): see reaction 9 in 9Be and (1974AJ01). Angular distributions have been measured at E(3He) = 1.56 to 5.27 MeV: see (1974AJ01).
| 5. (a) 7Be(d, n)8B | Qm = -2.087 | Eb = 16.489 |
| (b) 7Be(d, p)8Be | Qm = 16.6740 |
The cross section for reaction (a) for E(7Be) = 16.9 MeV is 58 ± 11 mb (1983HA17, 1985HA40). For Ed = 0.75 to 1.70 MeV, resonances in the yields of protons are observed at Ed = 0.900 ± 0.025 MeV ( p0, p1) and 1.475 ± 0.010 MeV (p1 only) with Γc.m. = 120 ± 40 and 71 ± 8 keV, respectively [9B* = 17.19 and 17.64 MeV]: see (1974AJ01). See also (1985CA41; astrophys.).
| 6. (a) 9Be(p, n)9B | Qm = -1.851 |
| (b) 9Be(p, pn)8Be | Qm = -1.6654 |
Angular distributions have been reported at many energies in the range Ep = 3.5 to 49.3 MeV [see (1979AJ01, 1984AJ01)] and at 16.44 and 17.57 MeV (1986MU07; n0).
The width of the ground state is 0.54 ± 0.21 keV: see (1974AJ01). At Ep = 135 MeV, neutron groups are reported to states at 0, 2.36, 2.71 ± 0.1 [Γ = 0.7 ± 0.1 MeV], 2.75 ± 0.3 [3.1 ± 0.2], 4.3 ± 0.2 [1.6 ± 0.2], 12.23 ± 0.1 [0.5 ± 0.1], 13.96 ± 0.1 [not broad] and 14.60 ± 0.1 [0.6 ± 0.1] MeV ((1985PU1A); Ph.D. thesis quoted and discussed in (1988MI03)) [Γ in MeV]. For the earlier work see (1979AJ01, 1984AJ01). Reaction (b) does not seem to involve states of 9B. See also (1984BA1R, 1988BO47, 1988HE08), (1984ALYS, 1987VO1F; applications), (1983BY02, 1987RA32) and (1982GU13; theor.). For yield and polarization measurements see 10B.
| 7. 9Be(3He, t)9B | Qm = -1.087 |
Angular distributions have been measured for E(3He) = 3.0 to 25 MeV and at 217 MeV: see (1974AJ01, 1979AJ01). At E(3He) = 39.8 MeV, 9Bg.s. is strongly populated and 9B*(2.4, 14.7) are also observed: see (1974AJ01). At E(3He) = 90 MeV triton groups are reported to states at Ex = 1.16 ± 0.05 [1.3 ± 0.05], 4.8 ± 0.03 [1.5 ± 0.3], 16.7 ± 0.1 [< 0.1], 18.6 ± 0.3 and 20.7 ± 0.5 [1.6 ± 0.3] MeV [Γ in MeV], in addition to 9B*(2.36, 2.79, 7.0) and unresolved states at higher Ex (1987KA36). See also (1983DJZV).
| 8. (a) 9Be(6Li, 6He)9B | Qm = -4.575 |
| (b) 9Be(7Li, 7Be)9B | Qm = -1.930 |
At E(6Li) = 32 MeV angular distributions are reported to 9B*(0, 2.36) (1985CO09). A weak group between these two may have been populated (1987BUZZ; prelim.). See also (1984GL06; E(6Li) = 93 MeV, E(7Li) = 78 MeV).
| 9. 9C(β+)9B | Qm = 16.498 |
The β+ decay is observed to 9B*(0, 2.36, 2.8) [Jπ = 3/2-, 5/2-, 1/2-] with branching ratios of (60 ± 10), (17 ± 6) and (11 ± 5)%. A state at Ex = 12.1 ± 0.6 MeV, Γ = 0.4 ± 0.1 MeV is also observed. The remaining strength goes to it (1988MI03; and D. Mikolas, priv. comm.). See also (1988MI1G). For an earlier study on delayed protons observed in the decay of 9C see reaction 9 and Table 9.10 (in PDF or PS) in (1974AJ01).
| 10. (a) 10B(p, d)9B | Qm = -6.212 |
| (b) 10B(p, pn)9B | Qm = -8.436 |
Angular distributions are reported at Ep = 18.6 MeV involving 9B*(0, 2.36) (1985BE13). For other observed groups see Table 9.10 (in PDF or PS). For reaction (b) see (1985BE30, 1985DO16; Ep = 1 GeV; prelim.). See also (1988GUZW).
| 11. 10B(d, t)9B | Qm = -2.179 |
Angular distributions have been measured at Ed = 11.8 to 28 MeV [see (1974AJ01, 1979AJ01)] and 18 MeV (1988GO02; to 9B*(0, 2.36)). See also (1983DJZV), (1988GUZW) and (1984SHZJ; theor.).
| 12. (a) 10B(3He, α)9B | Qm = 12.141 |
| (b) 10B(3He, αp)8Be | Qm = 12.3267 |
| (c) 10B(3He, 2α)5Li | Qm = 10.45 |
α-particle spectra show the excitation of 9B*(0, 2.4, 2.8, 11.8): see (1966LA04). Ex = 2.361 ± 0.005 and 2.788 ± 0.030 MeV, Γ = 81 ± 5 and 548 ± 40 keV, respectively. There is some evidence for a state with ≈ 6 MeV, Γ ≈ 0.7 MeV, but it is not conclusive. No evidence is found for any narrow levels in 9B with Γ ≤ 100 keV and 4 < Ex < 7 MeV: the upper limit to the intensity of the corresponding α-group is 1% of the intensity of the group to 9B*(2.4). Angular distributions have been determined at E(3He) = 5.5 and 33.7 MeV [see (1974AJ01)] and at E(3He) = 22.7 MeV (1987VA1I; to 9B*(0, 2.36); prelim.).
In reaction (b) study of the decays of 9B*(2.4, 2.8) shows that 9B*(2.4) decays < 0.5% by proton emission to 8Be(0) [it decays to 5Li(0) by α-emission] while the second state, Ex = 2.71 ± 0.03 MeV [Γ = 0.71 ± 0.06 MeV], decays almost 100% by that channel [θ2 = 0.74]. No other excited states of 9B with 3.5 < Ex < 9.5 MeV decay by proton emission to 8Be(0): see (1974AJ01). In a kinematically complete experiment (reaction(c)) at E(3He) = 2.3 and 5.0 MeV, the Ex of 9B*(4.8) is estimated to be 4.9 ± 0.2 MeV, and its width to be 1.5 ± 0.3 MeV (1986AR14). A preliminary report of a study of reactions (b) and (c) at E(3He) = 2.3 and 5 MeV suggests Ex = 1.8 ± 0.3 MeV, Γ = 0.9 ± 0.3 MeV (1988AR05). See also (1983DJZV) and (1988GOZB; theor.).
| 13. 11B(p, t)9B | Qm = -11.409 |
At Ep = 45 MeV angular distributions have been obtained for the triton groups to 9B*(0, 2.36, 12.06, 14.01, 14.66, 16.02). In addition the spectra show some indication of the groups corresponding to 9B*(7.0, 17.19, 17.64). T = 1/2 states are reported at Ex = 15.29 ± 0.04 and 15.58 ± 0.04 MeV. The first two T = 3/2 states have been observed at Ex = 14.6550 ± 0.0025 and 17.076 ± 0.004 MeV [Γ = 22 ± 5 keV]: see (1974AJ01, 1979AJ01). See also (1987KW01; theor.).
| 14. (a) 12C(p, α)9B | Qm = -7.552 |
| (b) 12C(p, p)4He4He4He | Qm = -7.27473 |
| (c) 12C(p, pt)9B | Qm = -27.366 |
Angular distributions have been measured at Ep = 14.0 to 54.1 MeV [see (1974AJ01)] and at Ep = 42.8 MeV (1983PE07; to 9B*(0, 2.36, 6.98)). The transitions to these three states involve L = 1, 3 and 3, respectively (1983PE07). Earlier work is consistent with Jπ = 7/2-, Γ = 2 MeV, Ex = 6.97 ± 0.06 MeV. A state at 2.9 ± 0.2 MeV has also been reported: see (1974AJ01). Angular distributions involving the α0 and α* groups [to 4He*(20.1), 0+] to 9Bg.s. have been studied at Ep = 42 MeV: see (1984AJ01). For reaction (c) see (1985DE17; Ep = 58 MeV). See also (1984AJ01) and (1985MAZG, 1986GO28, 1987GA08; theor.).
| 15. 12C(3He, 6Li)9B | Qm = -11.570 |
Angular distributions have been studied at E(3He) = 30.0 and 40.7 MeV [see (1974AJ01)] and at E(pol. 3He) = 33.4 MeV (1986CL1B; to 9B*(0, 2.36); also Ay; prelim.).
| 16. 12C(α, 7Li)9B | Qm = -24.898 |
Angular distributions have been measured at Eα = 49.0 and 80.1 MeV (1984GO03). See also (1984AJ01).