
^{10}Be (1979AJ01)(See Energy Level Diagrams for ^{10}Be) GENERAL: See also (1974AJ01) and Table 10.1 [Table of Energy Levels] (in PDF or PS). Shell model: (1977JA14). Cluster and αparticle models: (1977SE1D). Special levels: (1974IR04, 1976IR1B, 1977JA14). Electromagnetic transitions: (1976VO1C, 1977BO1V, 1977FL05). Astrophysical questions: (1973WE1D, 1974RA09, 1974SC1D, 1975GA1D, 1976DA1F, 1976FU1B, 1976GI1C, 1976LI1K, 1976PE1A, 1976RA1C, 1976SC1F, 1976SI1C, 1976VI1A, 1977AU1B, 1977DW1A, 1977GA1C, 1977HA1L, 1977MA1H, 1977WE1D, 1977WE1F, 1978BU1G, 1978ME1D, 1978YO1C). Special reactions: (1974FO22, 1974LA18, 1974RA09, 1975AB1D, 1975CO1E, 1975GR13, 1975KU01, 1975RA12, 1975RA14, 1975RA21, 1975ZE01, 1976BU16, 1976LE1F, 1976MI13, 1976OS04, 1976RA1C, 1976VA29, 1977AR06, 1977FE1B, 1977GO07, 1977MO1C, 1977ST1G, 1977YA1B, 1978GE1C, 1978GR1F, 1978WE1D). Muon capture and reactions: (1973MU1B, 1975KN1C, 1978DE15). Pion capture and reactions: (1974MI06, 1975BA52, 1975RE01, 1976NO1D, 1977AS1D, 1977BA1Q, 1977DO06, 1978BH01, 1978PE1D). Applied topics: (1976LI1K, 1977MU1B, 1978GU1F, 1978MU1C, 1978RA1E). Other topics: (1974CA1H, 1974IR04, 1976IR1B). Ground state properties: (1975BE31, 1976BE1G, 1977BA2E, 1977FL05).
The halflife of ^{10}Be is (1.6 ± 0.2) × 10^{6} y; log ft = 13.42: see (1974AJ01). The spectrum is of the D_{2} type (1950WU1A). See also (1973TA30, 1976BE1E) and (1975SZ03; theor.).
The yield of γ_{0} and γ_{1} has been studied for E_{t} = 0.5 to 3.0 MeV (1973BL1B; unpublished): see (1974AJ01) and for E_{t} = 0.4 to 1.1 MeV (1978SU02) [^{10}Be*(17.79) is said to be involved]. 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 (1960SE12, 1961VA43, 1962SE1A). Studies of reaction (c) have suggested the formation of the T = 2 state in ^{10}Be but they have not been published: see (1974AJ01). For reaction (d) see (1974AJ01). For reaction (e) see (1975CI1B; σ for α_{0}; E_{t} = 75 to 400 keV) and (1966LA04). See also (1977SU1B). For total breakup into neutrons and αparticles see (1975JE04). See also (1975FO19; astrophys.). See also ^{6}He and ^{9}Li.
Angular distributions have been measured at E_{α} = 30 MeV (1960KL03, 1972ME07; p_{0}, p_{1}) and 50 MeV (1975BU27; p to ^{10}Be*(3.4, 6.0, 7.5, 10.7, 12.0, 17.8, 18.8)).
Angular distributions are reported for E(^{7}Li) = 2.1 to 5.75 MeV (1969CA1A; α_{1}, α_{2+3+4+5}), 3.5 to 5.75 MeV (1969CA1A; α_{0}) and 30.3 MeV (1971GL07; αgroups to ^{10}Be*(0, 3.4, 6.0, 7.4, 9.4, 10.7, 11.9, 17.9)). (1971GL07) also report an αgroup corresponding to ^{10}Be*(18.8). See also (1973OG1A, 1978KA1H) and ^{14}C in (1976AJ04).
The thermal capture section is 9.2 ± 1.0 mb (1973MU14). Reported γray transitions are displayed in Table 10.2 (in PDF or PS). See also (1978DU1E; applications).
The crosssection data are summarized in (1976GAYV). Recent measurements of the total cross section have been carried out at E_{n} = 0.002 to 0.3 eV (1975KA1F; as a function of the temperature of the Be sample), 0.5 to 20.0 MeV (1974SC1C), 1.5 to 14 MeV (1976AU1D), 5.9, 10.1 and 14.2 MeV (1977DR09; also σ_{el}), 20.7 to 43.9 MeV (1974BU05; several energies), 900 to 2600 MeV/c (1973SC01) and 34 to 273 GeV/c (1974JO13, 1975MU1B). Differential elastic cross sections have been measured for E_{n} = 7 to 15 MeV by (1976BI1B, 1976HO1B). See also ^{9}Be and (1974AJ01). The coherent scattering length (thermal, unbound) is 7.74 ± 0.10 fm (1973MU14). Five resonances are reported in the total cross section at E_{n} = 0.63, 0.82, 2.73, (2.85) and 4.3 MeV; see Table 10.3 (in PDF or PS). Polarization and differential cross sections are reported for E_{n} = 0.2 to 2 MeV by (1961LA1A, 1962EL01, 1964LA04). Analysis of these data leads to the 3^{}, 2^{+} assignments for ^{10}Be*(7.37, 7.55) (1964LA04). 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 (1964LA04). 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^{} (1951BO45, 1966SC16). 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) (1966SC16). A weak dip at E_{n} ≈ 4.3 MeV is ascribed to a level with J ≥ 1 (1961FO07). The analyzing power has been measured for E_{nbar} = 1.6 to 4.8 MeV (1975HO01). See also (1974HE1E), (1975HO1F, 1975RO1G) and (1978BY1B; theor.).
Data on inelastic and nonelastic cross sections are summarized by (1976GAYV); 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. Cross sections for reaction (a) [to ^{9}Be*(2.4)] and (b) are also reported by (1977DR09; E_{n} = 5.9, 10.1 and 14.2 MeV) and for reactions (b) and (c) by (1976VE1A; E_{n} = 14.7 to 24.0 MeV). Inelastic and nonelastic cross sections are also reported by (1974WE11; 2.46 to 3.92 MeV), (1976BI1B, 1976HO1B; E_{n} = 7 to 15 MeV) and (1974HY01; 14.1 MeV). See also (1974AJ01, 1974CA1J, 1974KO35).
Cross sections have been measured at E_{n} = 14.1, 14.5 and 14.9 MeV (1973AU1A, 1974AU01). See also (1974BO1E, 1976GAYV).
The cross section for the (n, d) reaction has been measured for E_{n} = 16.3 to 18.7 MeV (1969SC05).
The (n, t_{1}) cross section has been measured for E_{n} = 13.3 to 15.0 MeV: at the lower energy it is 7.3 ± 0.7 mb (1976DI13). At E_{n} ≈ 22.5 MeV the cross section for triton production is 44 ± 12 mb (1978QA01). See also (1973BI1B, 1975BI07, 1977DR09).
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 (1957ST95). From E_{n} = 3.9 to 8.6 MeV, the cross section decreases smoothly from 100 mb to 32 mb (1961BA53). At E_{n} = 14.4 MeV, the total cross section for the α_{0} transition is 11.7 ± 1.8 mb (1967PA03). Excitation functions have been measured for α_{0} and α_{1} for E_{n} = 12.2 to 18.0 MeV (1976SM02). See also (1974BO1E, 1974CA1J, 1976GAYV).
At E_{p} = 185 MeV the π^{+} spectrum shows groups corresponding to ^{10}Be*(0, 3.37 ± 0.12, 6.07 ± 0.13, 7.39 ± 0.13, 9.31 ± 0.24, 11.75 ± 0.11). Angular distributions have been obtained for the π^{+} corresponding to these six states (1973DA09). Angular distributions are also reported at E_{pbar} = 200 MeV to ^{10}Be*(0, 3.37) (1978AU07). See also reaction 3 in ^{10}C.
Angular distributions of proton groups have been studied at many energies. Except at the lowest energies the stripping process appears to dominate. In addition to the earlier work [E_{d} = 0.3 to 15 MeV: see (1966LA04, 1974AJ01)] angular distributions have been measured at E_{d} = 0.15 to 2.50 MeV (1974CH1L; p_{0}, p_{1}), 0.6 to 2.7 MeV (1974FR02; p_{0}, p_{1}), 0.9 to 2.5 MeV (1974BO42, 1974BO45, 1974BO48; p_{0}, p_{1}), 0.9 to 3.1 MeV (1975ZW01; p_{0}, p_{1}: average S = 2.26 and 0.18), 17.3 MeV (1974AN27; p to ^{10}Be*(0, 3.37, 5.96, 6.26, 7.37, 7.54, 11.76); S = 0.94, 0.17, 0.54, 0.36, 0.20 for ^{10}Be*(0, 3.37, 5.96 [2^{+}], 7.37, 7.54)) and at E_{dbar} = 15 MeV (1976DA15). In the latter experiment 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, 6.26) (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 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 the 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 (1969AL17, 1969RO12), and lifetime measurements (1966WA10, 1968FI09, 1969AL17). For (p, γ) correlations through ^{10}Be*(3.37) see (1974AJ01) and (1975HU18, 1978AL25). For polarization measurements see ^{11}B in (1975AJ02, 1980AJ01). See also (1977TE1A), (1978MC1F; applied) and (1977RI08; theor.).
See (1974AJ01).
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 distributions have been measured at E(^{18}O) = 16 and 20 MeV (1971KN05).
Angular distributions 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. B(E2) for the ^{10}Be*(3.4) γ /→ ^{10}Be(0) transition is 23.8 e^{2} · fm^{4} (from a comparison of the angular distributions with DWBA predictions) (1970AU02).
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 (1974AJ01).
At E_{p} = 895 MeV, ^{10}Be*(0, 3.4, 17.7) are populated (1977AS1D, 1977AS1E).
Not reported.
See (1977KO27).
Transitions to ^{10}Be*(3.4) from upper region of the giant resonance in ^{11}B are reported to be about twice as intense as those from the lower region (1971PA10): see ^{11}B in (1975AJ02). Angular distributions of the p_{0} and p_{1} groups have been measured with E_{bs} = 18.5 MeV (1970SO03). The yield of the 3.37 MeV γray has been measured for E_{bs} = 100 to 800 MeV (1975AD04). See also (1977BR1J).
The angular distribution of the d_{0} group has been measured at E_{n} = 14.4 MeV (1968MI10, 1971MI12).
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 (1966LA04, 1966TY01) and ^{11}B in (1975AJ02).
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).
Angular distributions of α_{0} and α_{1} have been measured for E_{t} = 1.0 to 2.1 MeV (1969SI12). The γdecay of ^{10}Be*(6.18) has been studied: see Table 10.4 (in PDF or PS) (1975WA06). See also (1977CI1A) and ^{14}C in (1981AJ01).
See (1974AN36).
Angular distributions of the ground state transitions have been measured at E(^{14}N) = 41, 77 and 113 MeV (1971LI11).
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 (1976WE09, 1977WE1B, 1977WE03). See also (1974CE1A).
See (1972SC21, 1974AN36) and ^{14}O in (1976AJ04).
See (1974BA15, 1975CO15) and ^{20}Ne in (1978AJ03).
See (1974GO1J) and ^{14}C in (1970AJ04).
See (1974AN36).
