
^{10}Be (1984AJ01)(See Energy Level Diagrams for ^{10}Be) 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 ^{10}Be: (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). Groundstate properties of ^{10}Be: (1978SM02, 1981AV02, 1982NG01).
The halflife of ^{10}Be is (1.6 ± 0.2) × 10^{6} y; log ft = 13.42: see (1974AJ01). See also (1979FE1E; theor.) and (1979AJ01).
The yield of γ_{0} and γ_{1} has been studied for E_{t} = 0.4 to 1.1 MeV (1978SU02) [^{10}Be*(17.79) is said to be involved]. See also (1974AJ01). The neutron yield exhibits a weak structure at E_{t} = 0.24 MeV and broad resonances at E_{t} ≈ 0.77 MeV [Γ = 160 ± 50 keV] and 1.74 MeV: see (1966LA04) [^{10}Be*(17.79, 18.47)]. The total cross section for reaction (c), the yield of neutrons (reaction (b) to ^{9}Be*(14.39)), and the yield of γrays from ^{7}Li*(0.48) (reaction (e)) all show a sharp anomaly at E_{t} = 5.685 MeV: J^{π} = 2^{}; T = 2 is suggested for a state at E_{x} = 21.22 MeV. The total cross section for α_{0} (reaction (e)) and the allneutrons yield do not show this structure (1979AB11, 1980AB16, 1982AB1D, 1983ABZW). Differential cross sections and Sfactors are reported by (1983CE01) for E_{t} = 70 to 110 keV for ^{6}He*(0, 1.80). The zeroenergy Sfactor for ^{6}He*(1.80) is 14 ± 2.5 MeV · b. The relevance to an Liseeded tritium plasma is discussed by (1983CE01). See also (1974AJ01, 1979AJ01).
Angular distributions have been measured at E_{α} = 30 and 50 MeV: see (1979AJ01).
Angular distributions have been reported for E(^{7}Li) = 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 γray transitions are displayed in Table 10.2 (in PDF or PS).
The scattering amplitude (bound) a = 7.778 ± 0.003 fm, σ_{free} = 6.151 ± 0.005 b (1981MUZQ). Earlier crosssection measurements are listed in (1979AJ01, 1981MUZQ). Recent σ_{t} measurements have been reported for E_{n} = 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 crosssection data leads to the 3^{}, 2^{+} assignments for ^{10}Be*(7.37, 7.55). Below E_{n} = 0.5 MeV the scattering cross section reflects the effect of bound 1^{} and 2^{} states, presumably ^{10}Be*(5.960, 6.26). There is also indication of interference with swave background and with a broad l = 1, J^{π} = 3^{+} state. The structure at E_{n} = 2.73 MeV is ascribed to two levels: a broad state at about 2.85 MeV with J^{π} = 2^{+}, and a narrow one, Γ ≈ 100 keV, at E_{n} = 2.73 MeV with a probable assignment of J^{π} = 4^{}. The 4^{} assignment results from a study of the polarization of the n_{0} group at E_{n} = 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 ^{10}Be*(9.27). A weak dip at E_{n} ≈ 4.3 MeV is ascribed to a level with J ≥ 1. See (1974AJ01) for references. The analyzing power has been measured for E_{n} = 1.6 to 4.8 MeV (1975HO01) and E_{pol. n} = 9 to 15 MeV (1981FL1A, 1981FL04; n_{0}, n_{2}). See also (1981WA1G, 1983ANZY) and (1979BY01, 1983BY01; theor.).
The nonelastic and the (n, 2n) cross sections rise rapidly to ≈ 0.6 b (≈ 0.5 b for (n, 2n)) at E_{n} ≈ 3.5 MeV and then stay approximately constant to E_{n} = 15 MeV: see (1979AJ01). Recent measurmeents include those of (1978HO23; E_{n} = 6.97 to 14.94 MeV; inelastic cross sections to unresolved states at E_{x} = 1.7  3.1 MeV). A_{y} measurements are reported for the n_{2} group [to ^{9}Be*(2.4)] at E_{n} = 9 to 15 MeV (1981FL1A). For reaction (b) see also (1980BA2L; applied work) and (1978HE1F; theor.).
Cross sections have been meaasured at E_{n} = 14.1  14.9 MeV for reaction (a), 16.3 to 18.7 MeV for (b) and 13.3 to 15.0 (t_{1}) and 22.5 MeV (reaction (c)): see (1979AJ01). See also (1981HAZJ, 1982HA1A).
The cross section for production of ^{6}He 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 E_{n} = 3.9 to 8.6 MeV, the cross section decreases smoothly from 100 mb to 32 mb. Excitation functions have been measured for α_{0} and α_{1} for E_{n} = 12.2 to 18.0 MeV: see (1979AJ01) for references. See also (1981HAZJ, 1982HA1A).
Angular distributions have been studied at E_{p} = 185 MeV (1973DA09: to ^{10}Be*(0, 3.37, 6.07 ± 0.13, 7.39 ± 0.13, 9.31 ± 0.24, 11.76)), 200 MeV (1978AU07: to ^{10}Be*(0, 3.37)), 410 and 605 MeV (1980DI02: to ^{10}Be*(0, 3.37, 6.1)) and 800 MeV (1979HO13: to ^{10}Be*(0, 3.37, 11.8)); the latter may be unresolved). (1982AU02) have studied A_{y}(θ) for the π^{+} to ^{10}Be*(0, 3.37) for E_{pol. 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 E_{d} = 0.15 to 17.l3 MeV [see (1979AJ01)], at E_{d} = 2.0 to 2.8 MeV (1983DE1P; p_{0}, p_{1}) and at 698 MeV (1981BO03; p to ^{10}Be*(0, 3.37, 6.1, 7.37 + 7.54, 9.27 + 9.4, 11.8). At E_{d} = 15 MeV (1976DA15) find S = 2.1, 0.23 (j_{n} = 3/2) and 0.12 (j_{n} = 1/2), ≤ 1.0, 0.065 (j_{n} = 5/2) and 0.132 (j_{n} = 1/2), for ^{10}Be*(0, 3.37, 5.96, 6.62) (1976DA15). The angular distributions show l_{n} = 1 transfer for ^{10}Be*(0, 3.37, 5.958, 7.54), l_{n} = 0 transfer for ^{10}Be*(5.960, 6.26), l_{n} = 2 transfer for ^{10}Be*(7.37). ^{10}Be*(6.18, 9.27, 9.4) are also populated, as are two states at E_{x} = 10.57 ± 0.03 and 11.76 ± 0.02 MeV (1974AN27). ^{10}Be*(9.27, 9.4, 11.76) have Γ_{c.m.} = 150 ± 20, 291 ± 20 and 121 ± 10 keV (1974AN27). Attempts to understand the γdecay of ^{10}Be*(5.96) and its population in ^{9}Be(n, γ)^{10}Be led to the discovery that it consisted of two states separated by 1.6 ± 0.5 keV. The lower of the two has J^{π} = 2^{+} and decays primarily by a cascade transition via ^{10}Be*(3.37) [it is the state fed directly in the ^{9}Be(n, γ) decay]; the higher state has J^{π} = 1^{} and goes mainly by a crossover to ^{10}Be_{g.s.}. Angular correlations measured with ther γray detector located normal to the reaction plane (≡ angular distributions) lead to l_{n} values consistent with the assignments of 2^{+} and 1^{} for ^{10}Be*(5.9658, 5.9660) obtained from the character of the γdecay (1969RO12). ^{10}Be*(6.18) decays primarily to ^{10}Be*(3.37): E_{γ} = 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 ^{10}Be*(3.37) see (1974AJ01). For polarization measurements see ^{11}B in (1980AJ01). See also (1981CE04), (1974FI1D) and (1982GO05; theor.).
See (1980CO12; E(^{3}He) = 13 MeV) and ^{12}C in (1985AJ01).
Angular distributions have been studied at E_{α} = 65 MeV to ^{10}Be*(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(^{7}Li) = 34 MeV to ^{10}Be*(0, 3.4): S = 2.07 and 0.42(p_{1/2}), 0.38(p_{3/2}) (1977KE09).
Angular distrinbutions of the p_{0} and p_{1} groups have been measured at E_{p} = 12.0 to 16.0 MeV. The elastically scattered deuterons have been studied at E_{d} = 12.0 and 15.0 MeV: see (1974AJ01).
Differential cross sections have been measured for reaction (a) to ^{10}Be*(0, 3.37) for E_{γ} ≈ 230 to 340 MeV (1980BO24). Measurements are also reported at E_{π+} = 17, 29 and 48 MeV to ^{10}Be_{g.s.} and at the two higher energies for the transitions to ^{10}Be*(3.37) (1982RO04). See also (1981YA1A; E_{γ} ≈ 183 MeV; g.s.). At E_{e} = 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 ^{10}Be*(0, 3.37) are in good agreement with the M3 form factors. It is suggested that ^{10}Be*(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 ^{10}Be_{g.s.} as a function of E_{π+}. See also (1982DE14; theor.).
Partial capture rates leading to the 2^{+} states ^{10}Be*(3.37, 5.96) are reported by (1981GI08).
The total radiative capture branching ratio for stopped pions is (2.27 ± 0.22)%. The γspectrum is dominated by the transition to ^{10}Be*(6.0) [J^{π} = 2^{+}] (1975BA52). See also (1979AL1M) and (1979TR1B).
See (1979AJ01).
Angular distributions are reported at E_{d} = 55 MeV to ^{10}Be*(0, 3.37, 5.96, 9.4) (1979ST15).
^{11}Li populates several states of ^{10}Be, 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 I_{γ} = (0.95 ± 0.35), (1.65 ± 0.70), (3.5 ± 1.0) and (21 ± 6)%, respectively (1980DE39). See also ^{11}Be in (1985AJ01).
Transitions to ^{10}Be*(3.4) from the upper region of the giant resonance in ^{11}B are reported to be about twice as intense as those from the lower region: see ^{11}B in (1975AJ02). Angular distributions of the p_{0} and p_{1} groups have been measured with E_{bs} = 18.5 MeV and the yield of the 3.37 MeV γray has been reported for E_{b}s = 100 to 800 MeV: see (1979AJ01). See also (1982GO03; theor.).
The angular distribution of the d_{0} group has been measured at E_{n} = 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 E_{d} = 11.8 and 22 MeV to ^{10}Be_{g.s.} [see (1974AJ01)] and at 52 MeV to ^{10}Be*(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 ^{10}Be*(9.6) (1975SC41).
See (1979AJ01).
See (1974AJ01). See also (1978MA1F).
See (1979KO36).
At E(^{6}Li) = 80 MeV, ^{10}Be*(0, 3.37, 5.96, 7.54, (9.4), 11.8) are populated and the angular distribution to ^{10}Be_{g.s.} has been measured: see (1979AJ01). See also (1982AL08).
