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9Li (1966LA04)
(See Energy Level Diagrams for 9Li)
See also Table 9.1 [Table of Energy Levels] (in PDF or PS).
Mass of 9Li: From the Q-value for 7Li(t, p)9Li: Q = -2.397 ± 0.020 MeV, the mass excess of 9Li is 24.965 ± 0.020 MeV (1964MI04, 1965MA54).
| 1. 9Li(β-)9Be | Qm = 13.615 |
9Li decays to the ground state (25 ± 15 %) and to the 2.43 MeV, neutron-unstable state of 9Be (75 ± 15 %). The β-endpoints are 13.5 ± 0.3 MeV and 11.0 ± 0.4 MeV; log ft = 5.5 ± 0.2 and 4.7 ± 0.2, respectively. Delayed neutrons of energy 0.7 ± 0.2 MeV are associated with the 11 MeV branch; there are indications of a weak neutron group with En ≈ 3 - 4.5 MeV (1963AL18). (1963NE07) finds Eβ(max) = 13.1 ± 0.5 MeV, log ft = 5.0 ± 0.3. The mean of reported half lives is 172 ± 3 msec (1951GA30, 1952HO25, 1952SH44, 1961HI01, 1963AL18, 1965BE1P). The fact that the decay to 9Be(3/2-) is allowed indicates Jπ(9Li) = 1/2-, 3/2- or 5/2-; if 9Be*(2.43) has Jπ = 5/2-, the allowed decay excludes 1/2- (1963AL18). See also (1964ER1C).
| 2. 7Li(t, p)9Li | Qm = -2.397 |
At Et = 11.28 MeV, two groups are observed: the ground state group yields Q0 = -2.397 ± 0.020 MeV. The first excited state has Ex = 2.691 ± 0.005 MeV; no other states are seen with Ex < 4.0 MeV. The angular distribution of ground-state protons appears to require L = 0 and L = 2 transfer, consistent with the expected Jπ = 3/2- (1964MI04). See also (1961HI01, 1964RO1G).
| 3. 9Be(n, p)9Li | Qm = -12.832 |
| 4. 9Be(d, 2p)9Li | Qm = -15.057 |
See (1951GA30).
| 5. 9Be(t, 3He)9Li | Qm = -13.596 |
Not observed.
| 6. (a) 11B(γ, 2p)9Li | Qm = -30.875 |
| (b) 11B(p, 3p)9Li | Qm = -30.875 |
See (1952SH44, 1958TA04, 1963NE07) for reaction (a), and (1965BE1P) for (b).
| 7. 11B(n, 3He)9Li | Qm = -23.157 |
Not observed.
| 8. 12C(γ, 3p)9Li | Qm = -46.832 |