
^{10}Be (1988AJ01)(See Energy Level Diagrams for ^{10}Be) GENERAL: See also (1984AJ01) and Table 10.1 [Table of Energy Levels] (in PDF or PS). Model calculations: (1983MI1E, 1983SH38, 1984NI12, 1984VA06, 1985KW02). Special states: (1984NI12, 1984VA06, 1987AB1H, 1987BL18). Electromagnetic transitions: (1984NI12). Astrophysical questions: (1984BE1F, 1984EN1A, 1984NE1D, 1984SA1D, 1985WE1A, 1987EL1E, 1987GR1Q, 1987NA1M, 1987SO1E, 1988BE1B, 1988FE1A, 1988HA1M). Complex reactions involving ^{10}Be: (1983EN04, 1983OL1A, 1983WI1A, 1984GR08, 1984HI1A, 1984ST1B, 1985JA18, 1985MA13, 1985PO11, 1985TA18, 1985TR1B, 1986AN1F, 1986AV1B, 1986BA69, 1986CS1A, 1986HA1B, 1986ME06, 1986PO06, 1986SA30, 1986SIZS, 1986SO10, 1986WE1E, 1987AR19, 1987BA38, 1987BA39, 1987CH26, 1987DE37, 1987FE1A, 1987GR11, 1987GU04, 1987JA06, 1987KI05, 1987NA01, 1987TAZU, 1987TR05, 1987VI02, 1987VI14, 1987WA09, 1987YA16, 1988BL09, 1988CA06, 1988KI05, 1988KR11, 1988RU01, 1988SA19). Applications: (1983FA1B, 1983KU1C, 1983LI1A, 1983NE1A, 1983SH1G, 1983TU1A, 1984BE1F, 1984BE1H, 1984BO1E, 1984DO1B, 1984EL1B, 1984EL1C, 1984EN1A, 1984HE1B, 1984HE1C, 1984HO1E, 1984IM1A, 1984KL1A, 1984MA1K, 1984MI1D, 1984NE1C, 1984NE1E, 1984PO1C, 1984RA1D, 1984SE1B, 1984SE1D, 1984SH1L, 1984SO1A, 1984SO1B, 1984SP1B, 1984SU1B, 1984TU1A, 1984TU1C, 1984VA1D, 1985BE1D, 1985RA1A, 1985YI1A, 1986NI1A, 1986SU1H, 1986TE1A, 1987BE1X, 1987BR1Q, 1987BR1U, 1987DE1P, 1987EI1A, 1987EL1E, 1987GO1W, 1987GR1Q, 1987IN1A, 1987JA1G, 1987KU1L, 1987LA1G, 1987LA1I, 1987MO1F, 1987NA1M, 1987OE1A, 1987RA1N, 1987RE1H, 1987SE1D, 1987SE1E, 1987SH1N, 1987VA1S). Muon and neutrino capture and reactions: (1984KO24). Reactions involving pions and kaons (See also reactions 3, 10, 15 and 17.): (1982BE1D, 1984KA1C, 1985BE1K, 1985TU1B, 1986BE1P, 1986RA16). Hypernuclei: (1982KA1D, 1982WA1A, 1983BA1D, 1983FE07, 1983MI1E, 1983PO1D, 1984BO1D, 1984BO1G, 1984CH1G, 1984DZ1A, 1984ER1A, 1984KO1F, 1984SH1J, 1985AH1A, 1985IK1A, 1986AN1R, 1986BA1W, 1986BO1E, 1986DA1B, 1986MA1C, 1986PO1H, 1986WA1J, 1986ZH1B, 1987BO1L, 1987BO1O, 1987MI38, 1987PO1H, 1987WU05, 1988GI1B). Other topics: ( 1984PO11, 1985AN28, 1985WI1B). Groundstate properties of ^{10}Be: ( 1983ANZQ, 1984FR13, 1984NI12, 1985AN28, 1985SA32, 1985TA18, 1986WI04, 1987BL18, 1987HA30, 1987LE33, 1987SA15, 1988JO1C). The interaction nuclear radius of ^{10}Be is 2.46 ± 0.03 fm [(1985TA18), E = 790 MeV/A; see also for derived nuclear matter, charge and neutron matter r.m.s. radii]. B(E2) (↑) for ^{10}Be*(3.37) = (5.2 ± 0.6) × 10^{3} e^{2} · b^{2} [Q_{0} = 0.229 ± 0.013 b] (1987RA01).
The halflife of ^{10}Be is (1.51 ± 0.06) × 10^{6} y (1987HO1P). Log ft = 13.397 ± 0.017 (M.J. Martin, private communication). For the earlier work see (1974AJ01).
The yield of γ_{0} and γ_{1} has been studied for E_{t} = 0.4 to 1.1 MeV [^{10}Be*(17.79) is said to be involved]: see (1984AJ01). 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 (d)) 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: see (1983AB1A), (1984AJ01) and (1985DE19; theor.). An additional anomaly in the proton yield is also reported at E_{t} = 8.5 MeV [^{10}Be*(23.2)] [see (1987AB15)]. Differential cross sections and Sfactors are reported by (1983CE1A) 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 (1983CE1A). See also (1987AB09), (1985CA41; astrophys.) and (1986AB10; theor.).
Cross sections have been measured to ^{10}Be*(3.37, 6.2[u], 7.4[u] [u = unresolved]) at E(^{3}He) = 235 MeV. The groundstate group is not seen: its intensity at θ_{lab} = 20° is ≤ 0.1 that to ^{10}Be*(3.37) (1984BI08).
See (1987BI1C) and (1979AJ01).
See (1974AJ01).
The thermal capture cross section is 8.49 ± 0.34 mb (1986CO14). Reported γray transitions are displayed in Table 10.2 (1983KE11). Partial cross sections involving ^{10}Be*(0, 3.37, 5.96) are listed in (1987LY01). See also (1984SH1P, 1984SH1R) and (1985MU03, 1986MU1B, 1986RA1B, 1987LY01, 1988MU05; theor.). See 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). The difference in the spindependent scattering lengths, b^{+}  b^{} is +0.24 ± 0.07 (1987GL06). See also (1987LY01). Total cross section measurements have been reported for E_{n} = 2 × 10^{3} eV to 2.6 GeV/c [see (1979AJ01, 1984AJ01)] and at 24 keV (1983AI01), 7 to 15 MeV (1983DA22; also reaction cross sections) and 10.96, 13.89 and 16.89 MeV (1985TE01; for n_{0} and n_{2}). 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 ^{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 15 MeV [see (1984AJ01)] and at E_{n} = 9 to 17 MeV (1984BY03; n_{0}, n_{2}). 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, 1984AJ01). For total γray production cross sections for E_{n} = 2 to 25 MeV, see (1986GO1L). See also (1983GO1H, 1984SH1P, 1984SH1R, 1986MU07), (1985PE06; applications) and (1986DU1G, 1987HAZS; theor.).
Cross sections have been measured 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). A recent measurement (reaction (c)) has been reported at E_{n} = 14.6 MeV (1987ZA01). See (1983BO1C) and (1984SH1P, 1984SH1R, 1985BO1D).
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 (1983SH1J) and (1984SH1P, 1984SH1R).
Angular distributions have been studied at E_{p} = 185 to 800 MeV [see (1984AJ01)] and at E_{p} = 650 MeV (1986HO23; to ^{10}Be*(0, 3.37)). States at E_{x} = 6.07 ± 0.13, 7.39 ± 0.13, 9.31 ± 0.24, 11.76 MeV have also been populated. A_{y} measurements involving ^{10}Be*(0, 3.37) are reported at E_{p} = 200 to 250 MeV [see (1984AJ01)] and at 650 MeV (1986HO23).
Angular distributions of proton groups have been studied at many energies in the range E_{d} = 0.15 to 17.3 MeV and at 698 MeV [see (1979AJ01, 1984AJ01)], as well as at E_{d} = 2.0 to 2.8 MeV (1984DE46, 1984AN16; p_{0}, p_{1}; also VAP) and E_{d} = 12.5 MeV (1987VA13; p_{0}, p_{1}). At E_{d} = 15 MeV 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). 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. ^{10}Be*(9.27, 9.4, 11.76) have Γ_{c.m.} = 150 ± 20, 291 ± 20 and 121 ± 10 keV. See (1979AJ01) for references. 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 the γray detector located normal to the reaction plane (equiv. to angular distributions) lead to l_{n} values consistent with the assignments of 2^{+} and 1^{} for ^{10}Be*(5.9584, 5.9599) obtained from the character of the γdecay. ^{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. 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 (1987VA13) and references in (1974AJ01). For polarization measurements see ^{11}B in (1990AJ01).
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: see (1984AJ01).
Angular distributions have been measured at E(^{7}Li) = 34 MeV (reaction (a)) to ^{10}Be*(0, 3.4): S = 2.07 and 0.42 (p_{1/2}), 0.38 (p_{3/2}). See (1979AJ01). At E(^{9}Be) = 20 MeV an angular distribution involving ^{8}Be_{g.s.} + ^{10}Be_{g.s.} has been measured: transitions to excited states of ^{10}Be are very weak (1985JA09).
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: see (1974AJ01).
Differential cross sections have been measured to ^{10}Be*(0, 3.37) at E_{γ} =230 to 340 MeV [see (1984AJ01)] and at E_{e} = 185 MeV (1986YA07) and 200 MeV (1984BLZY). See also (1984AJ01).
Partial capture rates leading to the 2^{+} states ^{10}Be*(3.37, 5.96) have been reported: see (1984AJ01).
The photon spectrum from stopped pions is dominated by peaks corresponding to ^{10}Be*(0, 3.4, 6.0, 7.5, 9.4), and branching ratios have been obtained. Those to ^{10}Be*(0, 3.4) are (2.02 ± 0.17)% and (4.65 ± 0.30)%, respectively [absolute branching ratio per stopped pion] (1986PE05). See (1979AJ01) for the earlier work.
Angular distributions [reaction (b)] are reported at E_{d} = 55 MeV to ^{10}Be*(0, 3.37, 5.96, 9.4): see (1984AJ01). See also (1987KW01; theor.). For reaction (a) see (1974AJ01) and (1987LA16) in ^{11}B (1990AJ01).
^{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: see Table 11.2 (in PDF or PS) in (1985AJ01).
See (1984AL22) and ^{11}B in (1990AJ01). See also (1979AJ01).
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). See also (1985BE30, 1985DO16; prelim.).
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): see (1979AJ01).
See (1985PO02).
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, 1983AL20, 1985AL1G).
See (1987GIZZ) and ^{12}C in (1990AJ01).
See (1985KO04).
