
^{9}Be (1984AJ01)(See Energy Level Diagrams for ^{9}Be) GENERAL: See also (1979AJ01) and Table 9.2 [Table of Energy Levels] (in PDF or PS). Shell model: (1978AR1H, 1979LA06, 1981BO1Y, 1982OR03). Cluster and αparticle models: (1978AR1H, 1978RE1A, 1979CH1D, 1979FO16, 1979LU1A, 1979OK02, 1980FU1G, 1980RE02, 1981BA2N, 1981KR1J, 1982LA11, 1982OR03, 1982PO1B). Collective and rotaional models: (1979MA1J, 1981BA2N). Special states: (1979CH1D, 1979KI10, 1979OK02, 1980FU1G, 1981BO1Y, 1981SE06, 1982OR03, 1983GO1R). Electromagnetic transitions and giant resonance: (1979DO17, 1980MI1G, 1981BO1Y, 1981KO1Q, 1982AW02). Astrophysical questions: (1978BU1B, 1978OR1A, 1979MC1A, 1980CO1R, 1980RE1B, 1980WI1M, 1981AU1D, 1981AU1G, 1981GA1C, 1981SC1M). Applied work: (1979FO1F, 1979GR1E, 1979JUZU, 1980KI1B, 1981FA1E, 1981SA1G, 1981SC1D, 1982KL1A, 1982KU1G). Complex reactions involving ^{9}Be: (1978BE1G, 1978BH03, 1978DU1B, 1978HE1C, 1979AL22, 1979BA10, 1979BA34, 1979BO22, 1979BU1G, 1979DY01, 1979FR12, 1979GA04, 1979GE1A, 1979JA1C, 1979LO11, 1979SA17, 1979SA27, 1979SA1E, 1979SC08, 1979SC1D, 1979VI05, 1979WE06, 1980BR1P, 1980GR10, 1980ME1F, 1980MI01, 1980MO28, 1980WI1L, 1981BH02, 1981BL1G, 1981CI03, 1981HN02, 1981LE03, 1981ME13, 1981MO20, 1981TA16, 1981TA22, 1982BO1J, 1982BO35, 1982GU1H, 1982JA1C, 1982LU01, 1982LY1A, 1982MO1N, 1982WU1B, 1983FU04, 1983SA06). Muon and neutrino capture and reactions: (1977GR1C, 1980MU1B, 1980SC18, 1981MU1E). Reactions involving pions (See also reaction 17): (1978AR1J, 1978ER1A, 1978FU09, 1978GE11, 1978KI13, 1978VL1B, 1978WA1B, 1979AL1J, 1979BA16, 1979BO21, 1979BO1N, 1979BU1D, 1979CO1D, 1979DE06, 1979DE1G, 1979FR1F, 1979FU1G, 1979GI1B, 1979GI1C, 1979HO13, 1979HOZS, 1979IN1A, 1979KI1G, 1979MA02, 1979MA1P, 1979NA1E, 1979OH1A, 1979PE1D, 1979PI1C, 1979SC1E, 1979ST1G, 1979TI1A, 1979WI1E, 1980BU15, 1980CR03, 1980ER01, 1980HA29, 1980JE1C, 1980LE02, 1980MA1F, 1980NA1D, 1980NA1L, 1980NI03, 1980ST15, 1980TH1C, 1980TR1A, 1981AS1H, 1981BA2M, 1981BA2R, 1981BE13, 1981BE1X, 1981BE63, 1981BO06, 1981DU1H, 1981FE2A, 1981GE03, 1981IO01, 1981IS11, 1981KU15, 1981LE14, 1981MC09, 1981NA05, 1981NI03, 1981SEZR, 1981WA1H, 1981YA1A, 1982AP1A, 1982AS01, 1982GR1F, 1982MU1C, 1983AS02). Reactions involing kaons and other mesons: (1978AN1B, 1978DA1A, 1978SO1A, 1979GA1E, 1979LI1A, 1980AU1C, 1980BE30, 1980BE12, 1980DE11, 1980DO1E, 1980GA1C, 1980PO1A, 1981BA2N, 1981BE17, 1981BE45, 1981BO09, 1981DA1C, 1981HU1C, 1981KA1U, 1981PO1D, 1981WA1H, 1981ZH1C, 1982AB07, 1982BA17, 1982BO1U, 1982DEZQ, 1982DO1C, 1982ER1E, 1982PI1J, 1982PO1C). Hypernuclei: (1977KO1D, 1978DA1A, 1978PO1A, 1978SO1A, 1979GA1E, 1979VE1B, 1980AU1C, 1980BE30, 1980BE12, 1980DO1E, 1980GA1P, 1980GI1C, 1980PO1A, 1980ZH1C, 1980ZO1A, 1981BA2N, 1981BE17, 1981BE45, 1981BO09, 1981DA1C, 1981DA1D, 1981PO1D, 1981PO1F, 1981RE1B, 1981ST1G, 1981SU1D, 1981WA1J, 1982BA1P, 1982BA17, 1982BO1U, 1982DA1R, 1982DEZQ, 1982DO1C, 1982DO1M, 1982ER1B, 1982ER1E, 1982GA1J, 1982IK1A, 1982JO1C, 1982KO11, 1982MO1Q, 1982PO1C, 1982SH1P, 1982ZH1F, 1983BA2K, 1983JO1E). Other topics: (1978OS1B, 1979BE1H, 1979LA06, 1979LI1A, 1979OS02, 1980BOZN, 1980GI1C, 1981SE06, 1982AW02, 1982BA2G, 1982NG01, 1983BO1E, 1983GO1R). Groundstate properties of ^{9}Be: (1978HE1D, 1979AL26, 1979OK02, 1979SA27, 1980BOZN, 1981AV02, 1981BO1Y, 1981HN02, 1981SE06, 1982BA2G, 1982DE35, 1982LO13, 1982NG01, 1982OR03, 1983BO1E).
Q = +53 ± 3 mb: see (1978LEZA).
The 0° differential cross section for reaction (a) increases monotonically between E_{t} = 0.10 and 2.4 MeV except for a resonance at E_{t} = 1.875 MeV (^{9}Be* = 18.937). The excitation function for ^{8}Li (reaction (b)) increases monotonically for E_{t} = 0.275 to 1.000 MeV. In the range E_{t} = 2.0 to 6.8 MeV, a broad peak [Γ ≈ 1.3 MeV] is observed at E_{t} = 4.57 MeV [E_{x} = 20.73 MeV]: see (1974AJ01) for references. For reaction (d) see (1982CE1C). Cross sections for ^{7}Be production [reaction (f)] (E_{t} = 4.4 to 11.99 MeV) are reported by (1980GU26). For reactions (c) and (e) see (1966LA04).
Angular distributions of p_{0} have been measured at E_{α} = 10.2 to 14.7 MeV and at 30 MeV: see (1974AJ01). See also (1983BE1P; theor.).
For E_{d} = 0.1 to 1.1 MeV, a resonance in the yield of capture γrays is observed at E_{d} = 361 ± 2 keV, corresponding to ^{9}Be*(16.975) with Γ_{c.m.} < 0.47 keV. The small width of this state and its energy correspondence with ^{9}Li*(2.69) argue for T = 3/2. The angular distribution of the γrays to ^{9}Be(0) is isotropic to within 7%: see (1974AJ01) for references.
The yield of neutrons has been measured for E_{d} = 0.2 to 23 MeV: observed resonances are displayed in Table 9.3 (in PDF or PS). For polarization measurements [E_{d} = 0.64 MeV and 2.5 to 3.7 MeV] see (1974AJ01). See also (1979SE04; theor.). The yields of αparticles have been measured for E_{d} = 0.25 to 0.75 MeV (1977RO1C; α_{1}) and 0.2 to 3.0 MeV: see Table 9.3 (in PDF or PS). For reaction (c) see (1974AJ01) and ^{5}He. The ^{7}Be production cross section (reaction (d)) has been studied for E_{d} = 5.38 to 11.94 MeV (1980GU26). See also (1978BA1F, 1979JO1B; applications).
Excitation functions have been measured for E_{d} = 0.29 to 7 MeV [see (1974AJ01, 1979AJ01)] and 0.60 to 1.2 MeV (1982EL03, 1982FI03; σ_{t}) and 0.7 to 3.4 MeV (1979MI1E; σ_{t}): observed resonances are displayed in Table 9.3 (in PDF or PS). Recent measurements of the total cross section at the E_{d} = 0.78 MeV resonance are 181 ± 8 mb (1976SC14), 174 ± 16 mb (1979MI1E), 146 ± 13 mb (1982EL03) and 148 ± 12 mb (1982FI03): we adopt 147 ± 9 mb. See also (1983FI01). For earlier values see (1974AJ01). This cross section serves as normalization for the ^{7}Be(p, γ)^{8}B data and to calculations of the Sfactor. The new value predicts that the neutrinocapture rate in ^{37}Cl should be decreased by about 15%. Polarization measurements are reported at E_{d} = 4 MeV (1982WAZS). See also (1980HU1D, 1982AB1D) and ^{8}Li.
The elastic scattering [E_{d} = 0.4 to 1.8 MeV] shows a marked increase in cross section for E_{d} = 0.8 to 1.0 MeV (perhaps related to ^{9}Be*(17.30)) and a conspicuous anomaly at E_{d} = 1.0 MeV, due to pwave deuterons [^{9}Be*(17.50)]. The elastic scattering has also been studied for E_{d} = 1.0 to 2.6 MeV and 10.0 to 12.0 MeV: see (1979AJ01). See also (1982AB1D) and ^{7}Li.
The cross section for reaction (a) rises steeply from threshold to 95 mb at E_{d} = 2.4 MeV and then more slowly to ≈ 165 mb at E_{d} = 4.1 MeV. The t_{0} yield curve (θ_{lab} = 155°) decreases monotonically for E_{d} = 10.0 to 12.0 MeV: see (1974AJ01). See also ^{6}Li. For reaction (b) see ^{6}He.
Observed proton groups are listed in Table 9.4 (in PDF or PS). The parameters for the particle and γdecay of observed states are displayed in Tables 9.5 (in PDF or PS) and 9.6 (in PDF or PS). Angular distributions have been reported in the range E(^{3}He) = 0.9 to 14 MeV: see (1974AJ01, 1979AJ01). See also (1981SL03), (1981VI1B) and ^{10}B. The γdecay of ^{9}Be*(14.39) [J^{π} = 3/2^{}; T = 3/2] has been measured by (1978DI08) and compared with the decay from the mirror state in ^{9}B: see Table 9.6 (in PDF or PS). No evidence is found for violation of the selection rule for ΔT = 1 mirror γ transitions (1978DI08).
Angular distributions of d_{0}, d_{1} and d_{2} are reported at E_{α} = 30 MeV: see (1974AJ01). See also (1980ZE05, 1983BE1P; theor.).
Angular distributions of α_{0} have been studied at E(^{7}Li) = 3.78 to 5.95 MeV: see (1974AJ01).
^{9}Li decays by β^{} emission with τ_{1/2} = 178.3 ± 0.4 msec to several ^{9}Be states: see (reaction 1 in ^{9}Li and Table 9.7 (in PDF or PS). Measurement of βα coincidences involving ^{9}Be*(11.28) show contributions from the direct n + 2α breakup process as well as the sequntial nemission to ^{8}Be*(2.9) [J^{π} = 2^{+}], followed by breakup into 2α (1981LA11, 1981NY1A). The branching ratio fop the ^{9}Be*(2.43) → ^{8}Be_{g.s.} + n decay is (6.4 ± 1.2)%. ^{9}Be*(2.78) [J^{π} = 1/2^{}] decays mainly to ^{8}Be_{g.s.} + n presumably by pwave neutron emission: see (reaction 13 in (1979AJ01). See also (1981JOZV) and (1979DE15; theor.).
The photoneutron cross section has been measured from threshold to 320 MeV: see Table 9.6 (in PDF or PS) in (1966LA04) and (1979AJ01). A pronounced peak occurs ≈ 29 keV above threshold with σ_{max} = 1.33 ± 0.24 mb. The shape of the resonance has been measured very accurately for E_{γ} = 1675 to 2168 keV. The FWHM of the peak is estimated to be 100 keV (1982FU11). See also (1983BA52; theor.). The cross section then decreases slowly to 1.2 mb at 40 keV above threshold. From bremsstrahlung studies, peaks in the (γ, Tn) cross section are observed corresponding to E_{x} = 1.80 and 3.03 MeV. At higher energies, using monoenergetic photons, the (γ, Tn) cross section is found to be relatively smooth from E_{γ} = 17 to 37 MeV with weak structures which correspond to E_{x} = 17.1, 18.8, 19.9, 21.4, 22.4, 23.8 [± 0.2] MeV and 27 ± 0.5 MeV (broad). In the range E_{γ} = 18 to 26 MeV the integrated (γ, n_{0}) cross section is < 0.1 MeV · mb, that for (γ, n_{1}) = 2.4 ± 0.4 MeV · mb and the combined integrated cross section for (γ, n) to ^{8}Be*(16.6) and (γ, α_{0}) to ^{5}He_{g.s.} is 13.1 ± 2 MeV · mb. The total absorption cross section has been measured for E_{γ} = 10 to 210 MeV: it rises to ≈ 5 mb at ≈ 21 MeV, decreases to about 0 at 160 MeV and then increases to ≈ 1.5 mb at 210 MeV. An integrated cross section of 156 ± 15 MeV · mb is reported for E_{γ} = 10 to 29 MeV as is resonant structure at E_{γ} = 11.8, (13.5), 14.8, 917.3), (19.5), 21.0, (23.0) and (25.0) MeV. Fine structure is also reported at E_{γ} = 20.47 ± 0.04 and 20.73 ± 0.04 MeV. See (1979AJ01) for references. See also (1978CH1E, 1979ZI1A, 1980AH1A, 1982DE1H), (1982BA1T; applications) and (1979BA60, 1979KI1D, 1980TA1D, 1981DE18, 1981DE33, 1981IS11; theor.).
The yield shows structure in the energy region corresponding to the ^{9}Be levels at 17  19 MeV followed by the giant resonance at E_{γ} ≈ 23 MeV (σ = 2.64 ± 0.30 mb). Structure attributed to eleven states of ^{9}Be with 18.2 < E_{x} < 32.2 MeV has also been reported. Integrated cross sections have been obtained for each of these resonances, and over different energy intervals for protons leading to ^{8}Li*(0 + 0.98, 2.26 + 3.21, 9.0, 17.0). Angular and energy distributions of photoprotons in various energy intervals have been studied by many groups: see (1974AJ01) for references. See also (1976MA34). For momentum spectra using tagged photons with E_{γ} = 180  420 MeV and 360  600 MeV, see (1980HO22) and (1982BA32), respectively. See also (1981AR04, 1981TA1T, 1983ST1G). The integrated cross sections are reported to be 1.0 ± 0.5 MeV · mb (E_{γ} = 21 → 33 MeV) for reaction (c) to ^{7}Li*(0 + 0.4) and 0.6 ± 0.3 MeV · mb (E_{γ} = 25 → 33 MeV) for reaction (d) to ^{6}Li(0). The total integrated cross section for [(γ, p) + (γ, pn) + (γ, d) + (γ, t)] is given as 33 ± 3 MeV · mb by (1966DE13), who also report resonances in the (γ, d) and (γ, t) cross sections corresponding to ^{9}Be*(26.0 ± 0.2) and ^{9}Be*(32.2 ± 0.3), respectively. See also (1974AJ01), (1980IS10, 1982AV06, 1983HO01, 1983LIZN) and (1981IS11, 1982SU09; theor.).
See (1980IS10, 1982NOZW). See also (1979AJ01) and (1983ZH1D; theor.).
b = 1.5^{+0.3}_{0.2} fm [b = oscillator parameter], < r^{2} > ^{1/2}_{M} = 3.2 ± 0.3 fm, Ω = 6 ± 2 μ_{N} · fm^{2} [this value of the magnetic octupole moment implies a deformation of the average nuclear potential]. The elastic scattering of electrons has been studied for E_{e} up to 700 MeV. Magnetic elastic scattering gives indications of both M1 and M3 contributions. See also (1978DE32). Inelastic scattering populates a number of levels: Table 9.8 (in PDF or PS) displays the parameters of the states. See (1974AJ01, 1979AJ01) for other work and for references. At E_{e} = 134.7 and 237 MeV (1979BU11) have determined transverse and longitudinal form factors for electrodisintegration in the region of the quasielastic scattering peak. They report the observation of E1 and E2 giant resonance peaks: see Table 9.8 (in PDF or PS). The quasielastic process has been studied in the range 250  580 MeV/c by (1978KU06). For reaction (c) see ^{8}Li. For reaction (e) see (1980ST15). (1979JE04) have measured the ratio π^{}/π^{+} in the electroproduction of 10 MeV pions. See also (1979SC1E) and the "General" section here. See also (1979FR1B, 1979FR1F, 1979FR1C, 1983LIZO), (1979MO1G, 1979TI1A, 1980MO1C, 1981MO1H, 1982DE1J) and (1978KE13, 1978TA1D, 1979OK02, 1980ER01, 1980FU1G, 1980SA1E, 1980ST15, 1981BO1T, 1981CH30, 1981DE1T, 1981IS11, 1981KE15, 1981LA1E, 1982BO1G, 1982KE1C, 1983BO1E, 1983OC01; theor.).
The elastic scattering, and inelastic scattering to ^{9}Be*(2.43, 6.76), have been studied at E_{π±} = 162 MeV (1978GE11) and 291 MeV (1981GE03). Quadrupole contributions appear to be quite important for the elastic scattering at 162 MeV (1978GE11), but are much less so at higher energy (1981GE03). The inelastic scattering suggest the importance of radial localization effects (1981GE03). For a study of the (π^{+}, π^{0}) reaction see (1981BO06). For measurements of inclusive charged pion scattering yields see (1981MC09).
The population of ^{9}Be*(0, 1.7, 2.4, 3.1, (6.8)) has been reported in this reaction: see (1974AJ01). For the neutron decay of these states see Table 9.5 (in PDF or PS). Angular distributions have been measured at E_{n} = 5.9 to 14.2 MeV [see (1974AJ01, 1979AJ01)] and at 3.5 to 7.1 MeV (1980CO1U; n_{0}, n_{2}), 6.97 to 14.93 MeV (1978HO23; n_{0}, n_{2}) and at 14.6 MeV (1982HAZK; n_{0}). See also (1981DAZZ, 1983ANZY), (1979BY01, 1980AK01; theor.) and ^{10}Be.
Elastic and inelastic scattering angular distributions have been studied at many energies in the range E_{p} = 5 to 1000 MeV [see (1974AJ01, 1979AJ01)] and at E_{p} = 2.31 to 2.73 MeV (1980BO1L; p_{0}), 35.2 MeV (1980FA07; p_{0}), 72 MeV (1982AU1B; p_{0}), 225 MeV (1981RO1F; p_{0}) and 1 GeV (1979AL26; p_{0}). The elastic distributions show pronounced diffraction maxima characteristic of the optical model. A quadrupoledeformed optical model potential is necessary to obtain a good fit to the p_{0} and p_{2} angular distributions: see (1974AJ01). The structure corresponding to ^{9}Be*(1.7) is asymmetric: the line shape peaks 25^{+15}_{11} keV above the threshold for ^{8}Be + n. The population of ^{9}Be*(1.7) has been studied for E_{p} = 4.2 to 5.5 MeV: it is consistent with a scattering length of about 20 fm between a neutron and ^{8}Be. The weighted mean of the values of E_{x} for ^{9}Be*(2.4) listed in (1974AJ01) is 2432 ± 3 keV. ^{9}Be*(3.1) has E_{x} = 3.03 ± 0.03 MeV, Γ = 250 ± 50 keV, J^{π} = 3/2^{+}, 5/2^{+}. Higher states are observed at E_{x} = 4.8 ± 0.2, 6.76 ± 0.06 [J^{π} = 1/2^{+}, 5/2^{+}, 7/2^{+} (but see below), Γ = 1.2 ± 0.2 MeV], 7.94 ± 0.08 (Γ ≈ 1 MeV), 11.3 ± 0.2 MeV (Γ ≈ 1 MeV), 14.4 ± 0.3 (Γ ≈ 1 MeV), 16.7 ± 0.3, 17.4 ± 0.3, 19.0 ± 0.4, 21.1 ± 0.5 and 22.4 ± 0.7 MeV [the five highest states are all broad]. For ^{9}Be*(2.4, 6.8) B(E2 ↑) = 49 ± 6 and 24 ± 4 fm^{4} and Γ(E2 ↓) = 0.0025 and 0.10 eV, respectively. The strong population of ^{9}Be*(2.4, 6.8) is consistent with the assumption that they have J^{π} = 5/2^{} and 7/2^{}, respectively, and are members of the groundstate K = 3/2^{} band. See (1966LA04, 1974AJ01) for references. The elastic scattering studied at E_{p} = 25 MeV (1974BI14) and 225 MeV (1981RO1F) shows that the depolarization parameter, D, deviates from unity and thus that a spinspin term must be included in the optical parameter. The spinflip probability at E_{pbar} = 31 MeV is ≈ 0 for the p_{2} group, which is expected in view of the collective nature of the transition (1981CO08). See also (1978AL1G) and (1979BY01, 1980KO1V, 1981BA50, 1981CO08, 1981GU1B, 1981GU1F, 1981KR17, 1982BA1X, 1982BA14, 1982GUZS; theor.).
The summed proton spectrum (reaction (a)) shows two peaks with Q = 16.4 ± 0.3 and 25.4 ± 0.5 MeV, corresponding to removal of a pproton and an sproton respectively, and a third peak of uncertain assignment (perhaps due to unresolved states) with Q = 32.3 ± 0.6 MeV. See (1974AJ01). See also (1979KO21; also for (p, pX)), (1979KRZX, 1981FR24). For reaction (b) see (1974AJ01). Reactions (c) and (f) are dominated by quasifree processes at E_{p} = 101.5 MeV: S_{α}(L = 0) = 0.45, S_{α}(L = 2) = 0.55 (1980NA09). See also (1982NA1N). Reaction (d) at E_{p} = 10  24 MeV involves the 5/2^{+} state [3.01 ± 0.02 MeV]. ^{9}Be*(4.7) is also involved (1978JE01). See also (1982PE1F). For pion production see (1979BU1D). See also (1979BA28) and (1978WO1A, 1979BO27, 1979DO03, 1979KI10, 1979MA1M, 1980BO12, 1981IS11; theor.).
Angular distributions have been reported in the range 1.0 to 410 MeV [see (1974AJ01, 1979AJ01)] and at E_{dbar} = 2.0 to 2.8 MeV (1982DE1P; d_{0}) and E_{d} = 12.17 to 14.43 MeV (1978TA12; d_{0}, d_{1}, d_{2}). Inelastic groups have been reported to ^{9}Be*(1.7), to states with E_{x} = 2431.9 ± 7.0 keV and 3040 ± 15 keV (Γ = 294 ± 20 keV), and to ^{9}B*(4.7, 6.8): see (1974AJ01). See also (1978ZE03, 1979DO03; theor.) and ^{11}B in (1985AJ01).
Angular distributions of elastically scattered tritons have been measured at E_{t} = 2.10 MeV [see (1974AJ01)] and at E_{pol. t} = 15 and 17 MeV (1978SC02). Reaction (b) at E_{t} = 4.2 and 4.6 MeV proceeds via ^{9}Be*(2.4): see (1974AJ01). See also (1981ME1D; theor.).
Angular distributions have been studied for E(^{3}He) = 1.6 to 32.6 MeV and at 217 MeV [see (1974AJ01, 1979AJ01)] and at E(^{3}He) = 46.1 MeV (1979GO07; elastic). For optical model parameters see references in (1979AJ01). At E(^{3}He) = 39.8 MeV, ^{9}Be*(1.7, 2.4, 3.1, 4.7, 6.8, 14.4) are populated. In a study of reaction (b) the (^{5}He + α) system is found to be mainly in an Sstate: the probability of finding such a cluster in ^{9}Be is N_{eff} = 0.05 (1975KA05). At E(^{3}He) = 2.1 to 2.7 MeV quasifree processes are reported by (1978AR21): see ^{8}Be. See also (1981DE1X) and (1979KA1G).
Angualr distributions have been studied at many energies in the range E_{α} = 5.0 to 104 MeV [see (1974AJ01)] and at E_{α} = 35.5 MeV (1982PE03; α_{0}, α_{1}, α_{2}, α_{4}, α_{5} and α to ^{9}Be*(11.28)) and 65 MeV (1980HA33; α_{0}, α_{2}, α_{5}). See (1972DE01) for a discussion of optical model parameters. The structure (^{5}He + α) for ^{9}Be is found to be much more probable than (^{6}Li + t ): the ratio of spectroscopic factors is about 30 (1972DE01). At E_{α} = 35.5 MeV, states belonging to the K = 3/2^{} groundstate band are strongly excited [^{9}Be*(0, 2.43, 6.76, 11.28); it is suggested that the latter has J^{π} = (9/2^{}); see, however, reaction 12]. The first three states belonging to the K = 1/2^{+} band are also excited [^{9}Be*(1.68, 3.05, 4.70)] (1982PE03; coupled channels analysis). For reaction (b) see (1974AJ01) and (1980ZH1A; 18 MeV) and (1980WA07; 140 MeV). S_{α} = 0.96 (1976WO11). For reaction (c) see (1974AJ01). See also (1978ZE03, 1981BA20, 1982BU1D; theor.).
Elastic angular distributions have been measured at E(^{6}Li) = 4, 6 and 24 MeV and at E(^{7}Li) = 24 and 34 MeV: see (1979AJ01).
Elastic angular distributions have been obtained at E(^{9}Be) = 5, 9, 12 and 16 MeV [see (1979AJ01)], at 14, 20 and 26 MeV (1979UN01) and at 40 to 55 MeV (1983OMZZ; also to ^{9}Be*(2.43); σ (fusion)).
Elastic angular distributions are reported at E(^{10}B) = 20.1 and 30 MeV (1980BO14).
Elastic angular distributions have been measured for reaction (a) at E(^{12}C) = 12, 15, 18 and 21 MeV and E(^{9}Be) = 14, 20, 26 and 43 MeV [see (1979AJ01)] and at E(^{9}Be) = 14, 20 and 26 MeV (1979UN01), 20 MeV (1979BO1K), 20 and 26.1 MeV (1979JA04), 50 MeV (1977ST20), 69.7 and 76.6 MeV (1979MA21) and 158.4 MeV (1983FUZY). For yield and fusion crosssection measurements see (1978MA44, 1979MA21, 1981JA09, 1982DEZL, 1982HU06). Elastic angular distributions for reaction (b) are reported at E(^{9}Be) = 14, 20 and 26 MeV (1979UN01) and 19.5 and 25.0 MeV (1979JA04). See also (1978TA1B, 1982JA1E) and (1978GR22, 1980BR05, 1980OH1B, 1981GR17, 1981HU07, 1982LO13, 1983DE1U; theor.).
Elastic angular distributions have been measured at E(^{14}N) = 25 and 27.3 MeV: see (1974AJ01). For fusion studies see (1981MAZL, 1982MAZA).
Elastic angular distributions have been reported in the range E(^{16}O) = 15 to 30 MeV [see (1979AJ01)] and at E(^{9}Be) = 14, 20 and 26 MeV (1979UN01) and 158.4 MeV (1983FUZY), as well as at E(^{18}O) = 12.1, 16 and 20 MeV [see (1974AJ01)]. See also (1981ST1P, 1982BE54), (1979HU1B, 1979MA30, 1979PAZY, 1981GR17, 1981GU1B; theor.).
Elastic angular distributions have been measured at E(^{9}Be) = 14, 20 and 26 MeV for reactions (a), (c), (d) and at 14 and 17 MeV for reaction (d): see (1979AJ01). Recent measurements are at E(^{9}Be) = 12 to 30 MeV (1980BO11, 1981HU08; reaction (d)), 14, 20 and 26 MeV (1978UN02, 1979UN01; reactions (a) (nat. Mg), (c), (d), (f)), 20 MeV (1978JA07; reaction (d)), 27 and 40 MeV (1981GL03; reaction (d)), 40 MeV (1981HN04; reactions (e), (f), (g)), 45 and 60 MeV (1980EC01; reactions (d), (f)), 50 MeV (1977ST20; reactions (d), (f)), 158.4 MeV (1983FUZY; reactions (b), (c)) and 121 and 201.6 MeV (1980ZI02; reaction (d)). For fusion studies see (1980EC03, 1983EC01). See also (1980EC04) and (1979SA1E, 1980HU09; theor.).
Forward angular distributions have been obtained at E_{d} = 15.0 MeV for the tritons to ^{9}Be*(0, 1.7, 2.4, 3.1). The groundstate transition is well fitted by l = 1. The transition to ^{9}Be*(1.7) [≈ 165 ± 25 keV] is consistent with J^{π} = 1/2^{+}, that to ^{9}Be*(2.4) is quite well fitted with l = 3 [J^{π} = 5/2^{}], and that to ^{9}Be*(3.1) [Γ = 280 ± 25 keV] is consistent with l = 2. No other narrow states are seen up to E_{x} = 5.5 MeV (1970AU02).
Angular distributions of the d_{0} and d_{1} groups have been measured at E_{n} = 14.4 MeV: see (1974AJ01). See also ^{11}B in (1980AJ01).
The summed proton spectrum at E_{p} = 460 MeV yields Q = 6.7 ± 0.5, 11.9 ± 0.5, 17.1 ± 0.6 (all l ≠ 0) and Q = 30.5 ± 0.6 MeV (l = 0): see (1974AJ01).
Angular distributions of the ^{3}He groups corresponding to ^{9}Be*(0, 2.4) have been studied at E_{d} = 11.8, 28 and 52 MeV [the latter also to ^{9}Be*(6.7)], and at E_{d} = 15 MeV: S = 0.72 and 0.82 for ^{9}Be*(0, 2.4). At E_{dbar} = 52 MeV ^{9}Be*(11.3) appears to be strongly populated: see (1979AJ01).
At E_{t} = 12.9 MeV αgroups are observed to the ground state of ^{9}Be and to excited states at E_{x} = 1.75 ± 0.03, 2.43, 3.02 ± 0.04 (Γ = 320 ± 60 keV), 11.27 ± 0.04 (Γ = 530 ± 70 keV), (14.4) [Γ ≈ 800 keV], 14.39 and 16.67 MeV. The T = 3/2 state ^{9}Be*(14.39) is very weakly populated [≈ 5% of intensity of α_{2}]. The angular distribution of the α_{2} group shows sharp forward and backward peaking. The α_{0} group is not peaked in the backward direction: see (1979AJ01). Angular distributions are also reported at E_{t} = 0.9 and 1.1 MeV to ^{9}Be*(2.4) (1980CI1B). A study at E_{t} = 1.0 to 3.2 MeV finds E_{x} = 1.750 ± 0.025 MeV, Γ = 220 ± 8 keV: see (1974AJ01). See also (1978KR16; theor.) and ^{13}C in (1981AJ01).
See ^{5}Li.
The angular distribution of t_{0} has been measured at E_{n} = 14.4 MeV: see (1974AJ01).
At E_{p} = 45 MeV angular distributions are reported for the ^{3}He ions corresponding to ^{9}Be*(0, 2.4, 11.8, 13.8, 14.39 [T = 3/2], 15.96 ± 0.04 [T = 1/2]). In addition one or more states may be located at ^{9}Be*(15.13). It is suggested that ^{9}Be*(11.8, 13.8, 15.96) are the J = 3/2^{}, T = 1/2 analogs to ^{9}B*(12.06, 14.01, 16.02). Angular distributions are also reported at E_{p} = 40 MeV. The intensity of the group to ^{9}Be*(3.1) is ≈ 1% of the groundstate group at that energy: see (1974AJ01). The excitation energy of the first T = 3/2 state is E_{x} = 14392.9 ± 1.8 keV (1974KA15), using Q_{m}. See also (1981CO2D) and ^{12}C in (1985AJ01).
Alpha groups reported corresponding to ^{9}Be*(0, 1.7, 2.4, 3.1). The width of ^{9}Be*(1.7) [E_{x} = 1.70 ± 0.01 MeV] is Γ_{c.m.} = 220 ± 20 keV. The weighted mean of the values of E_{x} of ^{9}Be*(2.4), reported in (1974AJ01), is 2425 ± 3 keV. The 5/2^{+} state is at E_{x} = 3.035 ± 0.025 MeV: Γ_{c.m.} = 257 ± 25 keV. The ratio Γ_{γ}/Γ of ^{9}Be*(1.7) ≤ 2.4 × 10^{5}, that for ^{9}Be*(2.4) is reported to be (1.16 ± 0.14) × 10^{4}. Since Γ_{γ} is known from (e, e') [see Table 9.8 (in PDF or PS): 0.089 ± 0.010 eV], Γ = 0.77 ± 0.15 keV. See (1974AJ01, 1979AJ01) for references. Angular distributions for α_{0} and α_{2} are reported at E_{d} = 0.39 to 3.9 MeV and at 12 MeV [see (1974AJ01, 1979AJ01)]. Reaction (b), at E_{d} = 10.4 and 12.0 MeV, proceeds via ^{9}Be*(2.4) and to some extent via ^{9}Be*(3.1, 4.7) and possibly some higher excited states. The dominant decay of ^{9}Be*(2.4) is to ^{5}He(0) + α while ^{9}Be*(3.1, 4.7) decay to ^{8}Be(0) + n. It should be noted, however, that the peaks corresponding to ^{9}Be*(3.1) have a FWHM of ≈ 1 MeV, which may imply that ^{9}Be*(2.8) is involved.
Angular distributions of the α_{0} group have been measured at E_{n} = 13.9 to 18.8 MeV [see (1974AJ01)] and at 14 MeV (1981HAZW). ^{9}Be*(1.7, 2.4, 3.1) are also populated. At E_{n} = 14.7 MeV (1981GU12) report the involvement of ^{9}Be*(6.76) which subsequently decays by nemission. Reaction (b) at E_{n} = 13 to 18 MeV populates ^{9}Be*(2.4). See also (1979SUZW), ^{12}C in (1980AJ01) and reactions 30 and 34 in ^{13}C in (1981AJ01).
Angular distributions have been obtained at E(^{3}He) = 70 MeV for the transitions to ^{9}Be*(0, 2.4) and ^{7}Be*(0, 0.43). Broad states at 2.9, 4.8 ± 0.2, 7.3 ± 0.2 and 11.9 ± 0.4 MeV are also populated (1976ST11).
At E_{α} = 65 MeV angular distributions have been measured for the transitions to ^{9}Be*(0, 2.4) (1976WO11). See also (1979BE1J).
See (1981GO16) in ^{12}C (1985AJ01).
See (1981RU09; E_{d} = 13.6 MeV).
