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Spatially-correlated overabundances of $^{15}$N and $^{18}$O observed in some low-density graphite meteoritic grains have been connected to nucleosynthesis taking place in the helium-burning shell during core-collapse supernovae. Two of the reactions which have been identified as important to the final abundances of $^{15}$N and $^{18}$O are $^{18}$F($n,\alpha$)$^{15}$N and $^{18}$F($n,p$)$^{18}$O. The relative strengths of the $^{18}$F($n,\alpha$)$^{15}$N and $^{18}$F($n,p$)$^{18}$O reactions depend on the relative $\alpha_0$ and $p_0$ decays from states above the neutron threshold in $^{19}$F in addition to other properties. Experimental data on the charged-particle decays from these highly excited states are lacking or inconsistent. Two experiments were performed using proton inelastic scattering from LiF targets and magnetic spectrographs. The first experiment used the high-resolution Q3D spectrograph at Munich to constrain properties of levels in $^{19}$F. A second experiment using the Orsay Split-Pole spectrograph and an array of silicon detectors was performed in order to measure the charged-particle decays of neutron-unbound levels in $^{19}$F. A number of levels in $^{19}$F have been identified along with their corresponding charged-particle decays. The first state above the neutron threshold which has an observed proton-decay branch to the ground state of $^{18}$O lies 68 keV above the neutron threshold while the $\alpha$-particle decays from the neutron-unbound levels are generally observed to be much stronger than the proton decays. Neutron-unbound levels in $^{19}$F are observed to decay predominantly by $\alpha$-particle emission, supporting the role of $^{18}$F($n,\alpha$)$^{15}$N in the production of $^{15}$N in the helium-burning shell of supernovae. Improved resonant-scattering reaction data are required in order to be able to determine the reaction rates accurately.

Classical novae result from thermonuclear explosions producing several $\gamma$-ray emitters which are prime targets for satellites observing in the MeV range. The early 511 keV gamma-ray emission depends critically on the $^{18}$F(p,$\alpha$)$^{15}$O reaction rate which, despite many experimental and theoretical efforts, still remains uncertain. One of the main uncertainties in the $^{18}$F(p,$\alpha$)$^{15}$O reaction rate is the contribution in the Gamow window of interference between sub-threshold $^{19}$Ne states and known broad states at higher energies. Therefore the goal of this work is to clarify the existence and the nature of these sub-threshold states. States in the $^{19}$Ne compound nucleus were studied at the Tandem-ALTO facility using the $^{19}$F($^3$He,t)$^{19}$Ne charge exchange reaction. Tritons were detected with an Enge Split-pole spectrometer while decaying protons or $\alpha$-particles from unbound $^{19}$Ne states were collected, in coincidence, with a double-sided silicon strip detector array. Angular correlations were extracted and constraints on the spin and parity of decaying states established. The coincidence yield at $E_x$ = 6.29 MeV was observed to be high spin, supporting the conclusion that it is indeed a doublet consisting of high spin and low spin components. Evidence for a broad, low spin state was observed around 6 MeV. Branching ratios were extracted for several states above the proton threshold and were found to be consistent with the literature. R-matrix calculations show the relative contribution of sub-threshold states to the astrophysically important energy region above the proton threshold. The levels schemes of $^{19}$Ne and $^{19}$F are still not sufficiently well known and further studies of the analogue assignments are needed. The tentative broad state at 6 MeV may only play a role if the reduced proton width is large.

Gamma-ray production cross section excitation functions have been measured for $30$, $42$, $54$ and $66$ MeV proton beams accelerated onto targets of astrophysical interest, $^{nat}$C, C + O (Mylar), $^{nat}$Mg, $^{nat}$Si and $^{56}$Fe, at the Sector Separated Cyclotron (SSC) of iThemba LABS (near Cape Town, South Africa). The AFRODITE array equipped with 8 Compton suppressed HPGe clover detectors was used to record $\gamma$-ray data. For known, intense $\gamma$-ray lines the previously reported experimental data measured up to $E_{p}\simeq$ $25$ MeV at the Washington and Orsay tandem accelerators were extended to higher proton energies. Our experimental data for the last 3 targets are reported here and discussed with respect to previous data and the Murphy \textit{et al.} compilation [ApJS 183, 142 (2009)], as well as to predictions of the nuclear reaction code TALYS. The overall agreement between theory and experiment obtained in first-approach calculations using default input parameters of TALYS has been appreciably improved by using modified optical model potential (OMP), deformation, and level density parameters. The OMP parameters have been extracted from theoretical fits to available experimental elastic/inelastic nucleon scattering angular distribution data by means of the coupled-channels reaction code OPTMAN. Experimental data for several new $\gamma$-ray lines are also reported and discussed. The astrophysical implications of our results are emphasised.

Among reactions with strong impact on classical novae model predictions, 30P(p,γ)31S is one of the few remained that are worthy to be measured accurately, because of their rate uncertainty, as like as 18F(p,α)15O and 25Al(pγ)26Si. To reduce the nuclear uncertainties associated to this reaction, we performed an experiment at ALTO facility of Orsay using the 31P(3He,t)31S reaction to populate 31S excited states of astrophysical interest and detect in coincidence the protons coming from the decay of the populated states in order to extract the proton branching ratios. After a presentation of the astrophysical context of this work, the current situation of the 30P(p,γ)31S reaction rate will be discussed. Then the experiment set-up of this work and the analysis of the single events will be presented.

The cosmological 7Li problem arises from the signi cant discrepancy of about a factor 3 between the predicted primordial 7Li abundance and the observed one. The main process for the production of 7Li during Big-Bang nucleosynthesis is the decay of 7Be. Many key nuclear reactions involved in the production and destruction of 7Be were investigated in attempt to explain the 7Li de cit but none of them led to successful conclusions. However, some authors suggested recently the possibility that the destruction of 7Be by 3He and 4He may reconcile the predictions and observations if missing resonant states in the compound nuclei 10C and 11C exist. Hence, a search of these missing resonant states in 10C and 11C was investigated at the Orsay Tandem-Alto facility through 10B(3He,t)10C and 11B(3He,t)11C charge-exchange reactions respectively. After a short overview of the cosmological 7Li problem from a nuclear physics point of view, a description of the Orsay experiment will be given as well as the obtained results and their impact on the 7Li problem.

The recent WMAP results tightly constrain the baryon density in the universe, which in turn constrains the light element abundance predicted in Standard Big Bang Nucleosynthesis (SBBN). There is a discrepance in the $^7$Li abundance which cannot be explained by uncertainties in the main reactions included in the SBBN. Up to now, the influence of the reaction $^7Be(d,p)2\alpha$ has been neglected. We have investigated this reaction at SBBN energies using a radioactive $^7$Be beam and a $(CD_2)_n$ self-supporting target at the CYCLONE RIB facility at Louvain-la-Neuve. The experimental method is briefly described. Preliminary results and consequences for primordial nucleosynthesis are discussed.

Excitation functions for the production of the 2.74, 6.13, 6.92, and 7.12 MeV $\ensuremath{\gamma}$ rays by inelastic proton scattering on ${}^{16}\mathrm{O}$ have been measured in steps of 200--500 keV for proton energies ${E}_{p}=8.4--20 \mathrm{MeV}.$ For the 4.44 MeV $\ensuremath{\gamma}$ rays of ${}^{12}\mathrm{C}$ produced by inelastic proton scattering on ${}^{12}\mathrm{C}$ data have been obtained for proton energies ${E}_{p}=8.4--14 \mathrm{MeV}$ and at ${E}_{p}=17.25,18.25,$ and 19.75 MeV. Eight high efficiency Ge detectors with anti-Compton shielding for the $\ensuremath{\gamma}$-ray detection were used to obtain the laboratory $\ensuremath{\gamma}$-angular distributions. The results of Legendre polynom fits to these distributions are discussed and presented in suitable form for use in $\ensuremath{\gamma}$-ray astronomy.

A Coulomb excitation experiment has been performed in order to study the subshell closure atN = 40 for neutron-rich nuclei. This subshell effect is thought to be enhanced when largeN/Z ratios are encountered. Therefore, theZ = 2868Ni is of particular interest in order to test this behaviour. Some experimental information is already available for68Ni at low excitation energy: a 0+ 2 isomer, a 2+ state and a long-lived 5- state. The high energy of the 2+ state suggests the shell closure though its reduced transition probabilityB(E2) has never been mesured. The nuclei68Ni,70,72Zn,76Ge have been produced in the fragmentation of a86Kr beam at 60 MeV/A. The selection of these secondary beams has been performed by LISE3 spectrometer at GANIL. Performances of the detector system “Château de Cristal” and preliminary results on reduced transition probabilitiesB(E2) are presented and discussed.

Fragment angular correlations in projectile breakup reactions are very sensitive to interference between different multipolarities entering in the excitation-dissociation process of the projectile. In particular, it was proposed to disentangle L = 1 and L = 2 contributions in direct breakup reactions of 16 O with low relative energy between the α and 12 C fragment, which are of astrophysical interest. We studied the experimental aspects of extracting those angular correlations in extreme kinematical conditions usually encountered in breakup experiments of astrophysical interest. The breakup of 95 MeV/ A 16 O projectiles induced by a 208 Pb target was measured using the high-resolution spectrometer SPEG at Ganil for the coincident detection of the fragments. Sequential breakup via the 12.53 MeV level of 16 O is analyzed in this framework and it favors an one-step M2 excitation of this level.

The7Be(p,γ)8B cross section has been re-measured using radioactive targets. The zero-energy astrophysical S-factor is found significantly lower than the previously adopted value.

Nucleosynthesis of fluorine in the context of helium burning occurs through the 15 N(α,γ) 19 F reaction. At temperatures where fluorine formation takes place in most astrophysical models, the narrow resonance associated with the 4.378 MeV level of 19 F is expected to dominate the reaction rate, but its strength is not known. We used a 15 N confined gas target to study this level by means of the transfer reaction 15 N 7 Li,t) 19 F at 28 MeV. Reaction products products were analysed with a split pole magnetic spectrometer and the angular distributions for the first 16 levels of 19 F were extracted. These distributions are fairly well reproduced by FR-DWBA calculations in the framework of an α-cluster transfer model with a compound-nucleus contribution obtained by Hauser-Feshbach calculations. α-spectroscopic factors were deduced and, for unbound levels, the α-widths were determined and compared with the existing direct measurements. The α-width of the level of astrophysical interest ( E x = 4.378 MeV) was found to be Γ α = 1.5 × 10 −9 eV, a value 60 times smaller than the commonly used one. The astrophysical consequences for 19 F production in AGB stars are discussed.

We present some preliminary calculations on cross sections for the breakup of {sup 16}O around 100 MeV/nucleon with emphasis on the effect of nuclear breakup on the angular distributions. Underlying the results of these calculations, the possibilities and problems of extracting the astrophysical {ital S} factor for the {sup 12}C({alpha},{gamma}){sup 16}O reaction at very low energies are discussed. Some considerations on the experimental conditions for a {sup 16}O breakup experiment aiming at this astrophysical information are given.

In stellar-evolution models, the 13N(p, γ)14O reaction plays an important role in the hot CNO cycle. Its reaction rate depends directly on the magnitude of the radiative width of the 5.17 MeV level in 14O. That width has been measured using the Coulomb break-up technique. A 70 MeV u 14O beam was excited in the Coulomb field of a 208Pb target, the 13N and proton fragments being recorded using a magnetic spectrometer and CsI scintillators, respectively. The experimental value Γγ = 2.4 ± 0.9 eV is in overall agreement with other recent measurements.

The recently claimed observations of non-negligible amounts of $^{6}\mathrm{Li}$ in old halo stars have renewed interest in the Big Bang nucleosynthesis (BBN) of $^{6}\mathrm{Li}$. One important ingredient in the predicted BBN abundance of $^{6}\mathrm{Li}$ is the low-energy $^{2}\mathrm{H}$($\ensuremath{\alpha}$,$\ensuremath{\gamma}$)$^{6}\mathrm{Li}$ cross section. Up to now, the only available experimental result for this cross section showed an almost constant astrophysical $S$ factor below $400$ keV, contrary to theoretical expectations. We report on a new measurement of the $^{2}\mathrm{H}$($\ensuremath{\alpha}$,$\ensuremath{\gamma}$)$^{6}\mathrm{Li}$ reaction using the breakup of $^{6}\mathrm{Li}$ at 150 $A $ MeV. Even though we cannot separate experimentally the Coulomb contribution from the nuclear one, we find clear evidence for Coulomb-nuclear interference by analyzing the scattering angular distributions. This is in line with our theoretical description, which indicates a drop of the ${S}_{24}$ factor at low energies as predicted also by most other models. Consequently, we find even lower upper limits for the calculated primordial $^{6}\mathrm{Li}$ abundance than before.

INTEGRAL and RHESSI spacecrafts recently detected the 1.173 and 1.333 MeV γ‐ray lines coming from the 60Fe—60Co—60Ni radioactive decay chain. The long lived isotope 60Fe (T1/2 = 1.5 106y) is believed to be primarily produced in core‐collapse supernovae. However the interpretation of the observations is difficult because of the large uncertainties concerning 59Fe(n,γ)60Fe and 60Fe(n,γ)61Fe cross sections, involved in 60Fe nucleosynthesis.The direct component of the 60Fe(n,γ)61Fe reaction was studied indirectly via the d(60Fe,pγ)61Fe transfer reaction. The experiment performed in GANIL in spring 2009 will allow to determine the excitation energies of the populated excited states of 61Fe and for the first time their spectroscopic factors as well as their transfer angular momentum.I will first give an overview of the astrophysical context, then I will describe the experimental setup and finally present some preliminary results of the ongoing analysis.

The differential cross sections for the 3H(7Li, n0)9Be reaction were measured at 5 angles in the energy range E(c.m.)=0.2–0.9 MeV using a pulsed 7Li beam and time-of-flight technique. Absolute values of the cross section were obtained by comparison with the well-known cross section of 3H(d, n)4He at Ed=1.0 MeV. The resulting reaction rates are obtained at temperatures relevant to big-bang nucleosynthesis, and consequences for primordial 9Be abundances are discussed.

Coulomb dissociation of light nuclear projectiles in the electric field of heavy target nuclei has been experimentally investigated as an alternative access to radiative capture cross sections at low relative energies of the fragments, which are of astrophysical interest. As a pilot experiment the breakup of 156 MeV {sup 6}Li projectiles at {sup 208}Pb with small emission angles of the {alpha} particle and deuteron fragments has been studied. Both fragments were coincidentally detected in the focal plane of a magnetic spectrograph at several reaction angles well below the grazing angle and with relative angles between the fragments of 0{degree}--2{degree}. The experimental cross sections have been analyzed on the basis of the Coulomb breakup theory. The results for the resonant breakup give evidence for the strong dominance of the Coulomb dissociation mechanism and the absence of nuclear distortions, while the cross section for the nonresonant breakup follows theoretical predictions of the astrophysical {ital S} factor and extrapolations of corresponding radiative capture reaction cross section to very low c.m. energies of the {alpha} particle and deuteron. Various implications of the approach are discussed.

The reaction 13C(α,n)16O is considered as the main neutron source for s‐process in low‐mass asymptotic giant branch stars. At low energies of astrophysical interest, the contribution of the subthreshold state 6.356 MeV of 17O to the 13C(α,n)16O cross section should be taken into account. However, the results of previous studies of this contribution lead to different conclusions.Hence, we investigated the effect of this resonance on the astrophysical S‐factor through a new precise measurement of the alpha spectroscopic factor, Sα, of the 6.356 MeV state using the transfer reaction 13C(7Li,t)17O at two different incident energies. The measured angular distributions and the obtained spectroscopic factors will be presented as well as their impact on C(α,n)16O cross section and reaction rate.

In solar flares with strong γ‐ray emission, several prominent narrow lines can usually be observed emerging from a broad structure in the several hundred keV to several MeV region. They are produced by interactions of energetic protons, 3He and α‐particles with the most abundant isotopes in the solar atmosphere. The underlying continuum is due to electron and positron bremsstrahlung and to the superposition of broad lines from accelerated heavy ions as well as numerous narrow nuclear lines which are too weak to be resolved individually. The properties of the accelerated particles in the October 28, 2003 flare observed with the gamma‐ray spectrometer SPI onboard INTEGRAL were deduced by comparison of prominent narrow line fluence ratios, the line shapes of the 4.4 MeV 12C and 6.1 MeV 16O lines and the total nuclear line emission in the framework of a thick target interaction model.

The F-18, produced during nova explosions, is the main responsible for the 511 keV gamma-ray emitted during the outburst that could be detected with satellite missions or future gamma-ray telescopes. In spite of many experimental efforts, the amount of F-18 synthesized still suffers from large uncertainties concerning mainly the F-18(p, alpha)O-15 reaction. We report here on a new direct measurement of the F-18(p, alpha)O-15 cross section recently carried out at the RIB facility at Louvain-la-Neuve. Cross section data down to a center-of-mass energy of 400 keV have been obtained using an isobarically pure F-18 beam ( averaged intensity of the order of 10(6) pps) and a thin polyethylene target. The reaction products were detected using the multi-strip detector array LEDA. The cross section data are analysed in the framework of the R-matrix model. Our main aim is to determine the interference sign between three 3/2(+) resonances above threshold that can significantly affect the extrapolation of the F-18(p, alpha)O-15 cross section to the energies relevant for novae, and thus, the modeling of nova explosions.

A new experiment to determine the thermonuclear cross section of the C-12(alpha,gamma)O-16 reaction has been performed in regular kinematics using an intense alpha-particle beam of up to 340 mu A from the Stuttgart DYNAMITRON. For the first time, a 4 pi-germanium-detector setup has been used to measure the angular distribution of the gamma rays at all angles simultaneously. It consisted of an array of nine EUROGAM high-purity Ge detectors in close geometry, actively shielded individually with bismuth germanate crystals. The C-12 targets were isotopically enriched by magnetic separation during implantation. The depth profiles of the implanted carbon in the C-12 targets were determined by Rutherford backscattering for purposes of cross-section normalization and absolute determination of the E1 and E2 S factors. Angular distributions of the gamma decay to the O-16 ground state were measured in the energy range E-c.m.=1.30-2.78 MeV and in the angular range (lab.) 30 degrees-130 degrees. From these distributions, astrophysical E1 and E2 S-factor functions vs energy were calculated, both of which are indispensable to the modeling of this reaction and the extrapolation toward lower energies. The separation of the E1 and E2 capture channels was done both by taking the phase value phi(12) as a free parameter and by fixing it using the results of elastic alpha-particle scattering on C-12 in the same energy range.

We investigated the proton‐capture reactions on 17O occuring in classical nova explosions. We observed a previously undiscovered resonance at ERlab=194.1±0.6 keV in the 17O(p,α)14N reaction, with a measured resonance strength ωγpα=1.6±0.2 meV. We studied in the same experiment the 17O(p,γ)18F reaction by an activation method and the resonance‐strength ratio was found to be ωγpα/ωγpγ=470±50. The corresponding excitation energy in the 18F compound nucleus was determined to be 5789.8±0.3 keV by γ‐ray measurements using the 14N(α,γ)18F reaction. These new resonance properties have important consequences for 17O nucleosynthesis and γ‐ray astronomy of classical novae.

International audience; The possibility that big-bang nucleosynthesis (BBN) may produce nontrivial amounts of 6Li is under study since the recent observations of this element in old halo stars. However, the interpretation of these observations needs a precise knowledge of the reaction rate of D(alpha, gamma)6Li which, at present, is extremely uncertain (a factor of 20) at the energies of astrophysical interest (Ecm

We report on the observation of a previously unknown resonance at E=194.1+/-0.6 keV (lab) in the 17-O(p,alpha)14-N reaction, with a measured resonance strength omega_gamma(p,alpha)=1.6+/-0.2 meV. We studied in the same experiment the 17-O(p,gamma)18-F reaction by an activation method and the resonance-strength ratio was found to be omega_gamma(p,alpha)/omega_gamma(p,gamma)=470+/-50. The corresponding excitation energy in the 18-F compound nucleus was determined to be 5789.8+/-0.3 keV by gamma-ray measurements using the 14-N(alpha,gamma)18-F reaction. These new resonance properties have important consequences for 17-O nucleosynthesis and gamma-ray astronomy of classical novae., 4 pages, 4 figures. Accepted for publication in Physical Review Letters

Gamma-ray production cross sections have been measured for gamma-ray lines copiously emitted in the $^3$He bombardment of $^{16}$O nuclei: the 937, 1042 and 1081 keV lines of $^{18}$F and the 1887 keV line of $^{18}$Ne. Four Ge detectors with BGO shielding for Compton suppression were used to measure the angular distributions of the gamma-rays. The excitation functions have been obtained for $^3$He bombarding energies from 3.7 to 36 MeV. Total cross sections are tabulated for calculations relevant to gamma-ray astronomy. The importance of these lines as diagnosis for the presence and properties of accelerated $^3$He in solar flares is discussed in light of the measured cross sections.

The 18F(p,alpha) reaction was recognized as one of the most important for gamma ray astronomy in novae as it governs the early 511 keV emission. However, its rate remains largely uncertain at nova temperatures. A direct measurement of the cross section over the full range of nova energies is impossible because of its vanishing value at low energy and of the short 18F lifetime. Therefore, in order to better constrain this reaction rate, we have performed an indirect experiment taking advantage of the availability of a high purity and intense radioactive 18F beam at the Louvain La Neuve RIB facility. We present here the first results of the data analysis and discuss the consequences., Contribution to the Classical Novae Explosions conference, Sitges, Spain, 20-24 May 2002, 5 pages, 3 figures

The method of Coulomb breakup, applied to the determination of radiative capture cross sections at thermonuclear energies will be briefly introduced. In the following I will concentrate on the experimental requirements for a determination of the astrophysical S-factor using the Coulomb breakup reaction at intermediate energies for 6 Li and 16 O breakup. Interference of E1 and E2 contributions and of Coulomb and nuclear induced breakup are discussed and illustrated. Finally, some prospects concerning the future of Coulomb breakup studies are given.

The structure of nuclei far from stability can be investigated by means of in-beam gamma spectroscopy using both stable and radioactive beams. Two such experiments have been recently performed at GANIL. i) Secondary beams of neutron-rich Ge, Zn and Ni isotopes around N=40 were produced from the fragmentation of a primary 86 Kr beam, and analyzed by means of the LISE3 spectrometer. For the transitions between the 0+ ground state and the first 2+ state, B(E2) values have been extracted from Coulomb excitation cross-section measurement. Some of the obtained results related to the effectiveness of the N=40 spherical sub-shell closure are discussed. ii) In-beam γ-spectroscopy of neutron-rich nuclei around 32Mg produced by fragmentation of 36S have been performed recently. Gamma decay of relatively higher excited states have been measured in a large number of exotic light nuclei. Preliminary results obtained in a number of neutron-rich nuclei around N=20 are presented.

International audience; The structure of nuclei far from stability call be investigated by means of in-beam gamma spectroscopy using both stable and radioactive beams. A gamma -array consisting of BaF2 and Ge detectors have been used at GANIL in order to perform two of such experiments: i) Secondary beams of neutron-rich Ge, Zn and Ni isotopes around N=40 were produced from the fragmentation of a primary /sup 86/Kr beam, and analyzed by means of the LISE3 spectrometer. For the transitions between the 0/sup +/ ground state and the first 2/sup +/ state, B(E2) values have been extracted from Coulomb excitation cross-section measurement. Some of the obtained results related to the effectiveness of the N=40 spherical sub-shell closure as well as future improvements of the quality of the data are discussed. ii) In-beam gamma -spectroscopy of neutron-rich nuclei around /sup 32/Mg produced by fragmentation of /sup 36/S have been recently performed Gamma decay of relatively higher excited states have been measured in a large number of exotic light nuclei. Preliminary results obtained in a number of even-even nuclei around N=20, such as /sup 20,22/O, /sup 26,28/Ne and /sup 30,32/Mg are presented.

The Coulomb break-up technique has been used to determine the radiative width of one excited level in 12 N and the direct capture contribution to 11 C(p,γ) 12 N. The 12 N radioactive beam was produced through transfer and fragmentation reactions of a primary 95.5 MeV/u 14 N beam at GANIL. From the extracted cross section we deduce the rate of the 11 C+p reaction. Consequences for the hot pp chain are analysed.

The differential cross sections for the 3 H( 7 Li,n 0 ) 9 Be reaction were measured at 5 angles in the energy range E CM = 0.2–0.9 MeV using a pulsed 7 Li beam and time-of-flight technique. Absolute values of the cross section were obtained by comparison with the well known cross section of 3 H(d,n) 4 He at E d = 1.0 MeV. The resulting reaction rates are obtained at temperatures relevant to big-bang nucleosynthesis, and consequences for primordial 9 Be abundances are discussed.

These calculations are motivated by the recent observation of a high 9 Be abundance in a very metal poor star and the measurement of a key reaction rate for 9 Be synthesis. We study 9 Be production within the non-uniform density model of big bang nucleosynthesis: regions of both high and low density with a nonstandard n/p ratio may have emerged out after the quark-hadron phase transition leading to nonconventional nucleosynthesis. In addition to the elements produced in the standard model (SM) ( 4 He, D, 3 He, 7 Li), 9 Be may be significantly produced

Inclusive alpha particle and deuteron spectra from collisions of 156 MeV6Li-ions with12C and208Pb were measured at extreme forward emission angles including zero degree. The measurements were performed with the Karlsruhe magnetic spectrograph ‘Little John’ and required an efficient reduction of the background from small-angle scattering. The observed double differential cross sections and angular distributions have been analysed on the basis of Serber's spectator break-up model. When going to angles smaller than grazing, where Coulomb effects are expected to be dominating, transitional features may appear. Corresponding effects probably associated with Coulomb break-up are observed with the208Pb-target and require a slight extension of the Serber approach. In the case of the12C-target the break-up cross sections in forward direction seem to reflect the shape of the internal momentum distribution of the alpha particle and deuteron cluster in the6Li-projectile and are in agreement with a 2S-type wave function. However, at larger angles the shape appears to be distorted, possibly by final state interactions.

The triple-differential cross sections for elastic break-up of 156 MeV 6 Li projectiles by the reactions 208 Pb( 6 Li, αd) 208 Pb g.s. and 12 C( 6 Li, αd) 12 C g.s. have been measured with large asymptotic relative momenta of the outgoing fragments. The data exhibit rather unfamiliar shapes of the energy spectra, often replacing the usual bell-shape distributions by double-peaked structures and varying rapidly with the relative emission angles. The origin of these features has been explored and the cross sections have been analysed on the basis of a diffractive disintegration approach.

The measured ion-optical properties of the Karlsruhe magnetic spectrograph “Little John” and the properties of its detector system are described. Moreover, the procedures for an efficient use of the spectrograph, in particular concerning small angle and zero degree experiments, are presented in detail. Characteristic experimental results from 6 Li-induced nuclear reactions demonstrate the performance of the whole setup.