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10Be (1984AJ01)(See Energy Level Diagrams for 10Be) GENERAL: See also (1979AJ01) and Table 10.1 [Table of Energy Levels] (in PDF or PS). Model calculations: (1980FU1G, 1981DE2G). Special states: (1981DE2G, 1981SE06). Electromagnetic transiitons: (1982LA26, 1982RI04). Astrophysical questions: (1978BU1B, 1979MO04, 1979SI1D, 1980WI1M, 1981GA1B, 1981GA1C, 1981KR1C, 1981PR1B, 1981SA1G, 1982BR1N, 1982KU1J, 1982PA1F). Applied work: (1978MU1B, 1978RA1C, 1979GO1L, 1979IN1C, 1979LI1C, 1979RA1E, 1980EL1B, 1980EL1C, 1980GO1B, 1980KI1B, 1980LA1B, 1981FA1E, 1981LI1K, 1981RA1F, 1981SA1G, 1981SC1D, 1981TH1C, 1982BO35, 1982BR1N, 1982KL1A, 1982KU1G, 1982KU1J, 1982PA1F, 1983KR1B, 1983SO1B, 1983SU1C). Complex reactions involving 10Be: (1978DU1B, 1978HE1C, 1978TU06, 1979AL22, 1979BO22, 1979JA1C, 1979SC1D, 1979VI05, 1980GR10, 1980WI1L, 1981CI03, 1981MO20, 1982BI1C, 1982BO1J, 1982GU1H, 1982LU01, 1982LY1A, 1983SA06). Muon and neutrino capture and reactions: (1979GO1M, 1980MU1B, 1981GI08). Reactions involving pions and kaons (See also reactions 10, 16 and 18): (1978DA1A, 1978WA1B, 1979PE1C, 1980BO1B, 1981AU1C, 1981FE2A, 1981SI09, 1981WH01, 1981YA1A, 1982AU02, 1982RO04, 1982WA1G). Hypernuclei: (1978DA1A, 1978PO1A, 1978SO1A, 1980RO1F, 1980ZH1C, 1981WA1J, 1982IK1A, 1982KO1L, 1982KO11, 1982RA1L). Other topics: (1981SE06, 1982DE1N, 1982NG01). Ground-state properties of 10Be: (1978SM02, 1981AV02, 1982NG01).
The half-life of 10Be is (1.6 ± 0.2) × 106 y; log ft = 13.42: see (1974AJ01). See also (1979FE1E; theor.) and (1979AJ01).
The yield of γ0 and γ1 has been studied for Et = 0.4 to 1.1 MeV (1978SU02) [10Be*(17.79) is said to be involved]. See also (1974AJ01). The neutron yield exhibits a weak structure at Et = 0.24 MeV and broad resonances at Et ≈ 0.77 MeV [Γ = 160 ± 50 keV] and 1.74 MeV: see (1966LA04) [10Be*(17.79, 18.47)]. The total cross section for reaction (c), the yield of neutrons (reaction (b) to 9Be*(14.39)), and the yield of γ-rays from 7Li*(0.48) (reaction (e)) all show a sharp anomaly at Et = 5.685 MeV: Jπ = 2-; T = 2 is suggested for a state at Ex = 21.22 MeV. The total cross section for α0 (reaction (e)) and the all-neutrons yield do not show this structure (1979AB11, 1980AB16, 1982AB1D, 1983ABZW). Differential cross sections and S-factors are reported by (1983CE01) for Et = 70 to 110 keV for 6He*(0, 1.80). The zero-energy S-factor for 6He*(1.80) is 14 ± 2.5 MeV · b. The relevance to an Li-seeded tritium plasma is discussed by (1983CE01). See also (1974AJ01, 1979AJ01).
Angular distributions have been measured at Eα = 30 and 50 MeV: see (1979AJ01).
Angular distributions have been reported for E(7Li) = 2.1 to 5.75 MeV and at 30.3 MeV: see (1974AJ01).
The thermal capture cross section is 7.6 ± 0.8 mb (1981MUZQ). Reported γ-ray transitions are displayed in Table 10.2 (in PDF or PS).
The scattering amplitude (bound) a = 7.778 ± 0.003 fm, σfree = 6.151 ± 0.005 b (1981MUZQ). Earlier cross-section measurements are listed in (1979AJ01, 1981MUZQ). Recent σt measurements have been reported for En = 0.002 to 0.005 eV (1979ADZW), 23.5 keV (1975BL07; 5.903 ± 0.011 b), 1.0 to 13.5 MeV (1979AU07), 6.97 to 14.94 MeV (1978HO23; total elastic) and 200 to 590 MeV (1980FR1K). See also (1980AD1A). Observed resonances are displayed in Table 10.3 (in PDF or PS). Analysis of polarization and differential cross-section data leads to the 3-, 2+ assignments for 10Be*(7.37, 7.55). Below En = 0.5 MeV the scattering cross section reflects the effect of bound 1- and 2- states, presumably 10Be*(5.960, 6.26). There is also indication of interference with s-wave background and with a broad l = 1, Jπ = 3+ state. The structure at En = 2.73 MeV is ascribed to two levels: a broad state at about 2.85 MeV with Jπ = 2+, and a narrow one, Γ ≈ 100 keV, at En = 2.73 MeV with a probable assignment of Jπ = 4-. The 4- assignment results from a study of the polarization of the n0 group at En = 2.60 to 2.77 MeV. A rapid variation of the polarization over this interval is observed, and the data are consistent with 4-(l = 2) for 10Be*(9.27). A weak dip at En ≈ 4.3 MeV is ascribed to a level with J ≥ 1. See (1974AJ01) for references. The analyzing power has been measured for En = 1.6 to 4.8 MeV (1975HO01) and Epol. n = 9 to 15 MeV (1981FL1A, 1981FL04; n0, n2). See also (1981WA1G, 1983ANZY) and (1979BY01, 1983BY01; theor.).
The non-elastic and the (n, 2n) cross sections rise rapidly to ≈ 0.6 b (≈ 0.5 b for (n, 2n)) at En ≈ 3.5 MeV and then stay approximately constant to En = 15 MeV: see (1979AJ01). Recent measurmeents include those of (1978HO23; En = 6.97 to 14.94 MeV; inelastic cross sections to unresolved states at Ex = 1.7 - 3.1 MeV). Ay measurements are reported for the n2 group [to 9Be*(2.4)] at En = 9 to 15 MeV (1981FL1A). For reaction (b) see also (1980BA2L; applied work) and (1978HE1F; theor.).
Cross sections have been meaasured at En = 14.1 - 14.9 MeV for reaction (a), 16.3 to 18.7 MeV for (b) and 13.3 to 15.0 (t1) and 22.5 MeV (reaction (c)): see (1979AJ01). See also (1981HAZJ, 1982HA1A).
The cross section for production of 6He shows a smooth rise to a broad maximum of 104 ± 7 mb at 3.0 MeV, followed by a gradual decrease to 70 mb at 4.4 MeV. From En = 3.9 to 8.6 MeV, the cross section decreases smoothly from 100 mb to 32 mb. Excitation functions have been measured for α0 and α1 for En = 12.2 to 18.0 MeV: see (1979AJ01) for references. See also (1981HAZJ, 1982HA1A).
Angular distributions have been studied at Ep = 185 MeV (1973DA09: to 10Be*(0, 3.37, 6.07 ± 0.13, 7.39 ± 0.13, 9.31 ± 0.24, 11.76)), 200 MeV (1978AU07: to 10Be*(0, 3.37)), 410 and 605 MeV (1980DI02: to 10Be*(0, 3.37, 6.1)) and 800 MeV (1979HO13: to 10Be*(0, 3.37, 11.8)); the latter may be unresolved). (1982AU02) have studied Ay(θ) for the π+ to 10Be*(0, 3.37) for Epol. p = 200 and 250 MeV: little variation with E is observed. The cross section for π+ production near threshold has been studied by (1979MA38). See also the "General" section here, and (1981NI1B, 1982HO1C, 1982NA1K).
Angular distributions of proton groups have been studied at many energies in the range Ed = 0.15 to 17.l3 MeV [see (1979AJ01)], at Ed = 2.0 to 2.8 MeV (1983DE1P; p0, p1) and at 698 MeV (1981BO03; p to 10Be*(0, 3.37, 6.1, 7.37 + 7.54, 9.27 + 9.4, 11.8). At Ed = 15 MeV (1976DA15) find S = 2.1, 0.23 (jn = 3/2) and 0.12 (jn = 1/2), ≤ 1.0, 0.065 (jn = 5/2) and 0.132 (jn = 1/2), for 10Be*(0, 3.37, 5.96, 6.62) (1976DA15). The angular distributions show ln = 1 transfer for 10Be*(0, 3.37, 5.958, 7.54), ln = 0 transfer for 10Be*(5.960, 6.26), ln = 2 transfer for 10Be*(7.37). 10Be*(6.18, 9.27, 9.4) are also populated, as are two states at Ex = 10.57 ± 0.03 and 11.76 ± 0.02 MeV (1974AN27). 10Be*(9.27, 9.4, 11.76) have Γc.m. = 150 ± 20, 291 ± 20 and 121 ± 10 keV (1974AN27). Attempts to understand the γ-decay of 10Be*(5.96) and its population in 9Be(n, γ)10Be led to the discovery that it consisted of two states separated by 1.6 ± 0.5 keV. The lower of the two has Jπ = 2+ and decays primarily by a cascade transition via 10Be*(3.37) [it is the state fed directly in the 9Be(n, γ) decay]; the higher state has Jπ = 1- and goes mainly by a crossover to 10Beg.s.. Angular correlations measured with ther γ-ray detector located normal to the reaction plane (≡ angular distributions) lead to ln values consistent with the assignments of 2+ and 1- for 10Be*(5.9658, 5.9660) obtained from the character of the γ-decay (1969RO12). 10Be*(6.18) decays primarily to 10Be*(3.37): Eγ = 219.4 ± 0.3 keV for the 6.18 → 5.96 transition (1969AL17). See Table 10.4 (in PDF or PS) for a listing of the information on radiative transitions obtained in this reaction and lifetime measurements. For (p, γ) correlations through 10Be*(3.37) see (1974AJ01). For polarization measurements see 11B in (1980AJ01). See also (1981CE04), (1974FI1D) and (1982GO05; theor.).
See (1980CO12; E(3He) = 13 MeV) and 12C in (1985AJ01).
Angular distributions have been studied at Eα = 65 MeV to 10Be*(0, 3.37, 5.96, 6.26, 7.37, 7.54, 9.33, 11.88). DWBA analyses of these lead to spectroscopic factors which are in poor agreement with those reported in other reactions (1980HA33).
Angular distributions have been measured at E(7Li) = 34 MeV to 10Be*(0, 3.4): S = 2.07 and 0.42(p1/2), 0.38(p3/2) (1977KE09).
Angular distrinbutions of the p0 and p1 groups have been measured at Ep = 12.0 to 16.0 MeV. The elastically scattered deuterons have been studied at Ed = 12.0 and 15.0 MeV: see (1974AJ01).
Differential cross sections have been measured for reaction (a) to 10Be*(0, 3.37) for Eγ ≈ 230 to 340 MeV (1980BO24). Measurements are also reported at Eπ+ = 17, 29 and 48 MeV to 10Beg.s. and at the two higher energies for the transitions to 10Be*(3.37) (1982RO04). See also (1981YA1A; Eγ ≈ 183 MeV; g.s.). At Ee = 158.5 to 165.0 MeV the angular distributions of 12.3 ± 0.7 MeV pions are reported by (1982ZU03). The (e, π+) angular distributions to 10Be*(0, 3.37) are in good agreement with the M3 form factors. It is suggested that 10Be*(5.96) is also populated through an M1 transition. (1982ZU03) also present a review of the data for the 90° photopion cross section leading to 10Beg.s. as a function of Eπ+. See also (1982DE14; theor.).
Partial capture rates leading to the 2+ states 10Be*(3.37, 5.96) are reported by (1981GI08).
The total radiative capture branching ratio for stopped pions is (2.27 ± 0.22)%. The γ-spectrum is dominated by the transition to 10Be*(6.0) [Jπ = 2+] (1975BA52). See also (1979AL1M) and (1979TR1B).
See (1979AJ01).
Angular distributions are reported at Ed = 55 MeV to 10Be*(0, 3.37, 5.96, 9.4) (1979ST15).
11Li populates several states of 10Be, via delayed neutron emission. Gamma rays have been observed for the transitions 6.18 → 5.96, 6.18 → 3.37, 5.96 (unres.) → 3.37 and 3.37 → g.s. with Iγ = (0.95 ± 0.35), (1.65 ± 0.70), (3.5 ± 1.0) and (21 ± 6)%, respectively (1980DE39). See also 11Be in (1985AJ01).
Transitions to 10Be*(3.4) from the upper region of the giant resonance in 11B are reported to be about twice as intense as those from the lower region: see 11B in (1975AJ02). Angular distributions of the p0 and p1 groups have been measured with Ebs = 18.5 MeV and the yield of the 3.37 MeV γ-ray has been reported for Ebs = 100 to 800 MeV: see (1979AJ01). See also (1982GO03; theor.).
The angular distribution of the d0 group has been measured at En = 14.4 MeV: see (1974AJ01).
Structure is observed in the summed proton spectrum corresponding to Q = -10.9 ± 0.35, -14.7 ± 0.4, -21.1 ± 0.4, -35 ± 1 MeV: see (1974AJ01).
Angular distributions have been measured at Ed = 11.8 and 22 MeV to 10Beg.s. [see (1974AJ01)] and at 52 MeV to 10Be*(0, 3.37, 5.96, 9.60): S = 0.65, 2.03, 0.13, 1.19 (normalized to the theoretical value for the ground state); π = + for 10Be*(9.6) (1975SC41).
See (1979AJ01).
See (1974AJ01). See also (1978MA1F).
See (1979KO36).
At E(6Li) = 80 MeV, 10Be*(0, 3.37, 5.96, 7.54, (9.4), 11.8) are populated and the angular distribution to 10Beg.s. has been measured: see (1979AJ01). See also (1982AL08).
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