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Angular distributions of the analyzing powers iT{sub 11}, T{sub 20}, and T{sub 22} for {sup 1}H({rvec d},{gamma}){sup 3}He at 40{le}E{sub c.m.}{le}110 keV and the angular distribution of the analyzing power A{sub y} for {sup 2}H({rvec p},{gamma}){sup 3}He at 70{le}E{sub c.m.}{le}210 keV have been measured for the first time. In addition, absolute differential cross sections for proton-deuteron capture have been determined for E{sub c.m.}= 75, 108, 133, and 173 keV. Thick ice or heavy ice targets and two large-volume, high-purity Ge {gamma}-ray detectors were used. Results are in general agreement with an exact three-body calculation utilizing a realistic nucleon-nucleon potential. The vector-polarization observables are found to be especially sensitive to meson-exchange-current effects. The extracted S(0) value for proton-deuteron capture is {approximately}25{percent} lower than that presently used in astrophysical calculations. An expression for the thermonuclear reaction rate below 10 GK is given. {copyright} {ital 1997} {ital The American Physical Society}

The extraction of detailed nuclear structure information from transfer reactions requires reliable, well-normalized data as well as optical potentials and a theoretical framework demonstrated to work well in the relevant mass and beam energy ranges. It is rare that the theoretical ingredients can be tested well for exotic nuclei owing to the paucity of data. The halo nucleus Be-11 has been examined through the 10Be(d,p) reaction in inverse kinematics at equivalent deuteron energies of 12,15,18, and 21.4 MeV. Elastic scattering of Be-10 on protons was used to select optical potentials for the analysis of the transfer data. Additionally, data from the elastic and inelastic scattering of Be-10 on deuterons was used to fit optical potentials at the four measured energies. Transfers to the two bound states and the first resonance in Be-11 were analyzed using the Finite Range ADiabatic Wave Approximation (FR-ADWA). Consistent values of the spectroscopic factor of both the ground and first excited states were extracted from the four measurements, with average values of 0.71(5) and 0.62(4) respectively. The calculations for transfer to the first resonance were found to be sensitive to the size of the energy bin used and therefore could not be used to extract a spectroscopic factor., 16 Pages, 10 figures

1 Oak Ridge Associated Universities, Oak Ridge, TN 37830, USA. 2 Dept. of Physics & Astronomy, University of Tennessee, Knoxville, TN 37996, USA 3 Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA 4 Dept. of Physics & Astronomy, Rutgers University, New Brunswick, NJ 08903, USA 5 Dept. of Physics, Colorado School of Mines, Golden, CO 80401, USA 6 Dept. of Physics & Astronomy, Louisiana St. University, Baton Rouge, LA 70803, USA

Resonance scattering with rare isotope beams provides direct access to continuum properties of exotic nuclei and can serve as a stringent test for modern theoretical approaches. Properties of neutron deficient isotope 8B, that were studied using resonance scattering of protons of 7Be, are discussed and compared to the predictions of the ab initio theories. New experimental data on clustering in 10Be studied using 6He+α resonance elastic scattering is presented.

The coincident detection of particles and gamma rays allows the study of the structure of exotic nuclei via inverse kinematics reactions using radioactive ion beams and thick targets. We report on the status of the project to couple the highresolution charged-particle detector ORRUBA to Gammasphere, a high-efficiency, high-resolution gamma ray detector.

The study of nuclei far from stability elucidates the evolution of nuclear shell structure, and also affects estimates of heavy element nucleosynthesis in supernova explosions. Measurement of transfer reactions in inverse kinematics with radioactive ion beams is a powerful technique for these types of studies. Rare isotope beams often have relatively low intensities, and this places difficult requirements on the detection systems for reaction products. The detectors must provide large solid angle coverage in the laboratory along with good position and energy resolution. The Super ORRUBA detector array has been developed for such measurements and is comprised of 18 double-sided, nonresistive silicon strip detectors. This configuration features low thresholds and improved resolution over detectors employing charge division. As a first implementation of this system, the 80Ge(d,p)81Ge neutron transfer reaction in inverse kinematics was measured at HRIBF at ORNL, to determine the properties of levels in 81Ge.

The astrophysical rapid neutron-capture process (r-process) is believed to have produced approximately half of the nuclear species more massive than Fe. Unfortunately, almost nothing is known about the structure of the majority of the extremely neutron-rich nuclei involved in the reaction flow. At exotic beam facilities such as the Holifield Radioactive Ion Beam Facility (HRIBF), measurements with accelerated beams of fission fragments have provided some of the first spectroscopic information on many r-process nuclei. The new SuperORRUBA (Oak Ridge Rutgers University Barrel Array) detector has been constructed at the HRIBF to study such nuclei, and first results are presented.

New radioactive ion beam (RIB) facilities, like FRIB in the US or FAIR in Europe, will push further away from stability and enable the next generation of nuclear physics experiments. Thus, the need for improved RIB targets is more crucial than ever: developments in exotic beams should coincide with developments in targets for use with those beams, in order for nuclear physics to remain on the cutting edge. Of great importance to the future of RIB physics are scattering, transfer and capture reaction measurements of rare, exotic, and unstable nuclei on light targets such as hydrogen and helium. These measurements require targets that are dense, highly localized, and pure, and conventional targets often suffer too many drawbacks to allow for such experimental designs. Targets must also accommodate the use of large area, highly-segmented silicon detector arrays, high-efficiency gamma arrays, and novel heavy ion detectors to efficiently measure the reaction products. To address this issue, the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) Collaboration led by the Colorado School of Mines (CSM) is in the process of designing, building and testing a supersonic gas jet target for use at existing and future RIB facilities. The gas jet target provides a high density and high purity of target nuclei within a tightly confined region, without the use of windows or backing materials. The design also enables the use of multiple state-of-the-art detection systems.

We used the $^{16}\mathrm{O}$${(}^{3}$He,n${)}^{18}$Ne, $^{12}\mathrm{C}$${(}^{12}$C${,}^{6}$He${)}^{18}$Ne, and $^{20}\mathrm{Ne}$(p,t${)}^{18}$Ne reactions to study $^{18}\mathrm{Ne}$ states up to an excitation energy of 10 MeV, with emphasis on levels corresponding to $^{14}\mathrm{O}$(\ensuremath{\alpha},p${)}^{17}$F and $^{17}\mathrm{F}$(p,\ensuremath{\gamma}${)}^{18}$Ne resonances that could strongly affect these reaction rates in hot stellar environments. Excitation energies, widths, absolute cross sections, and angular distributions were measured. We found previously unidentified states at ${\mathit{E}}_{\mathit{x}}$=6.15\ifmmode\pm\else\textpm\fi{}0.01 MeV, 7.12\ifmmode\pm\else\textpm\fi{}0.02 MeV, 7.35\ifmmode\pm\else\textpm\fi{}0.02 MeV, 7.62\ifmmode\pm\else\textpm\fi{}0.02 MeV, 8.30\ifmmode\pm\else\textpm\fi{}0.02 MeV, (8.45\ifmmode\pm\else\textpm\fi{}0.03 MeV), 8.55\ifmmode\pm\else\textpm\fi{}0.03 MeV, 8.94\ifmmode\pm\else\textpm\fi{}0.02 MeV, and 9.58\ifmmode\pm\else\textpm\fi{}0.02 MeV. We combined level width, cross section, and angular distribution data to infer ${\mathit{J}}^{\mathrm{\ensuremath{\pi}}}$ values for a number of the new levels as well as for the previously known 5.1-MeV doublet. Using information from our experiments, we recalculated the $^{14}\mathrm{O}$(\ensuremath{\alpha},p${)}^{17}$F reaction rate, which constitutes a possible path out of the hot CNO cycle into the rp process and could play an important role in transforming nuclei involved in the hot CNO cycle into heavier nuclei with Z\ensuremath{\ge}10. \textcopyright{} 1996 The American Physical Society.

The {sup 7}Li({ital n},{gamma}){sup 8}Li cross section is important in inhomogeneous big bang models, and as a constraint on model parameters used to determine the solar {sup 7}Be({ital p},{gamma}){sup 8}B reaction rate. Values of the {sup 7}Li({ital n},{gamma}{sub 0}){sup 8}Li reaction cross section were measured for neutron energies between 1.5 and 1340 eV at the Oak Ridge Electron Linear Accelerator. The normalization of the cross section was determined by measuring the gamma-ray yield from the {sup 7}Li({ital n},{gamma}{sub 0}){sup 8}Li reaction relative to that from the {sup 10}B({ital n},{alpha}{gamma}){sup 7}Li reaction. The cross section was found to have the inverse neutron-velocity relationship (1/{ital v}) indicative of {ital s}-wave capture. These results help resolve ambiguities in previous measurements. {copyright} {ital 1996 The American Physical Society.}

Many astrophysical events, such as novae and X-ray bursts, are powered by reactions with radioactive nuclei. Studying the properties of these nuclei in the laboratory can therefore further our understanding of these astrophysical explosions. The TwinSol separator at the University of Notre Dame has recently been used to produce intense (~106 pps) beams of 17F. In this article, some of the first measurements with these beams are discussed.

The cross section for the astrophysically important {sup 17}O({ital p},{alpha}){sup 14}N reaction was measured at proton energies of 75 and 65 keV. Thick, high-purity Ta{sub 2}O{sub 5} targets (77% enriched {sup 17}O) and large-area detectors were used with beam currents of 0.45 mA. Backgrounds were measured using Ta{sub 2}O{sub 5} targets of natural isotopic composition. The expected resonance at {ital E}{sub {ital p}}=70 keV was observed in the data taken at 75 keV, and its proton width was found to be 22{plus_minus}3{sub stat}{plus_minus}2{sub target}{sub {minus}1}{sup +2}{sub beam} neV.

Recent calculations suggest that the rate of neutron capture by (130)Sn has a significant impact on late-time nucleosynthesis in the r process. Direct capture into low-lying bound states is expected to be significant in neutron capture near the N=82 closed shell, so r-process reaction rates may be strongly impacted by the properties of neutron single particle states in this region. In order to investigate these properties, the (d,p) reaction has been studied in inverse kinematics using a 630 MeV beam of (130)Sn (4.8 MeV/u) and a (CD(2))(n) target. An array of Si strip detectors, including the Silicon Detector Array and an early implementation of the Oak Ridge Rutgers University Barrel Array, was used to detect reaction products. Results for the (130)Sn(d, p)(131)Sn reaction are found to be very similar to those from the previously reported (132)Sn(d, p)(133)Sn reaction. Direct-semidirect (n,γ) cross section calculations, based for the first time on experimental data, are presented. The uncertainties in these cross sections are thus reduced by orders of magnitude from previous estimates.

The best examples of halo nuclei, exotic systems with a diffuse nuclear cloud surrounding a tightly-bound core, are found in the light, neutron-rich region, where the halo neutrons experience only weak binding and a weak, or no, potential barrier. Modern direct reaction measurement techniques provide powerful probes of the structure of exotic nuclei. Despite more than four decades of these studies on the benchmark one-neutron halo nucleus Be-11, the spectroscopic factors for the two bound states remain poorly constrained. In the present work, the Be-10(d,p) reaction has been used in inverse kinematics at four beam energies to study the structure of Be-11. The spectroscopic factors extracted using the adiabatic model, were found to be consistent across the four measurements, and were largely insensitive to the optical potential used. The extracted spectroscopic factor for a neutron in a nlj = 2s1/2 state coupled to the ground state of Be-10 is 0.71(5). For the first excited state at 0.32 MeV, a spectroscopic factor of 0.62(4) is found for the halo neutron in a 1p1/2 state., 5 pages, 4 figures

The 9 Be(α, p) 12 B has been used to populate states which could correspond to astrophysically significant resonances in the 8 Li(α, n) 11 B reaction. The branching ratios for neutron decays have been measured and the neutron angular distributions have been used to determine J π for these states. This information, combined with previous measurements of excitation energies and total widths, allows us to extract the resonance strengths for these states. The astrophysical significance of these results is discussed.

The ${}^{31}\mathrm{S}{(p,\ensuremath{\gamma})}^{32}$Cl reaction is expected to provide the dominant break-out path from the SiP cycle in novae and is important for understanding enrichments of sulfur observed in some nova ejecta. We studied the ${}^{32}\mathrm{S}{{(}^{3}\mathrm{He},t)}^{32}$Cl charge-exchange reaction to determine properties of proton-unbound levels in ${}^{32}$Cl that have previously contributed significant uncertainties to the ${}^{31}\mathrm{S}{(p,\ensuremath{\gamma})}^{32}$Cl reaction rate. Measured triton magnetic rigidities were used to determine excitation energies in ${}^{32}$Cl. Proton-branching ratios were obtained by detecting decay protons from unbound ${}^{32}$Cl states in coincidence with tritons. An improved ${}^{31}\mathrm{S}{(p,\ensuremath{\gamma})}^{32}$Cl reaction rate was calculated including robust statistical and systematic uncertainties.

Simultaneous measurement of the proton-transfer {sup 18}F(d, n){sup 19}Ne and neutron-transfer {sup 18}F(d, p){sup 19}F reactions were performed with a {sup 18}F radioactive beam at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The experiments clarify the nuclear structure of {sup 19}Ne near the proton threshold, which is relevant for understanding the rates of proton-induced reactions on {sup 18}F in novae. Analogs for several states in the mirror nucleus {sup 19}F have not yet been identified in {sup 19}Ne, indicating that the level structure of {sup 19}Ne in this region is incomplete. We observed 15 levels in {sup 19}Ne from the {sup 18}F(d, n){sup 19}Ne measurement and 18 levels in {sup 19}F from the {sup 18}F(d, p){sup 19}F measurement. Angular distributions were extracted for all strongly populated states and compared to distorted-wave Born approximation calculations. The angular distributions for all the known states in the two nuclei determined in this work are consistent with their previously assigned spins and parities. The spectroscopic factors determined for these levels in the two nuclei are reported.

Low-energy resonances in 31P(p, α 28Si and 35Cl(p, α)32S were studied directly in order to gain a better understanding of reaction cycling in the Si-Ar region in novae. New resonance strengths at E c.m. = 600 and 622 keV in 31P(p, α)28Si were measured (ωγ p, α = (2.2#x00B1;0.7) × 10−2 eV and ωγ p, α = (0.99±0.08) eV, respectively) as well as the E c.m. = 610 keV resonance in 35Cl(p, α)32S [ωγ p, α = (1.2±0.2) × 10−2 eV], the lowest energy that any resonance in this reaction has been observed, directly or indirectly. The strengths of these resonances were found to be lower than previously determined, resulting in even weaker cycling in the Si-Ar region.

Nucleon transfer experiments have in recent years begun to be exploited in the study of nuclei far from stability, using radioactive beams in inverse kinematics. New techniques are still being developed in order to perform these experiments. The present experiment is designed to study the odd-odd nucleus Na which has a high density of states and therefore requires gamma-ray detection to distinguish between them. The experiment employed an intense beam of up to 3×10 pps of Na at 5.0 MeV/nucleon from the ISAC-II facility at triumf. The new silicon array SHARC was used for the first time and was coupled to the segmented clover gamma-ray array TIGRESS. A novel thin plastic scintillator detector was employed at zero degrees to identify and reject reactions occurring on the carbon component of the (CD) target. The efficiency of the background rejection using this detector is described with respect to the proton and gamma-ray spectra from the (d,p) reaction. © Published under licence by IOP Publishing Ltd.

The level structure of 22Na has been studied at the Holifield Radioactive Ion Beam Facility in Oak Ridge National Laboratory using the 24Mg(p,3He)22Na reaction. 41 and 41.5 MeV proton beams were generated by 25 MV tandem accelerator and bombarded isotopically enriched 24Mg targets. Angular distributions of recoiling 3He particles were extracted by using a segmented annular silicon strip detector array. Spins and parities for ten levels were constrained through a distorted wave Born approximation analysis of angular distributions including three above the proton threshold at 6.739 MeV.

A recent discussion of the {sup 18}F(p,{alpha}) reaction [N. de Sereville et al., Phys. Rev. C 79, 015801 (2009)] questions our previous analysis of interference effects in this reaction. We address these questions and demonstrate that our previous analysis is indeed appropriate.

We directly measure the {sup 17}F(p,{gamma}){sup 18}Ne resonant reaction using a mixed beam of {sup 17}F and {sup 17}O at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory (ORNL). The astrophysically important 3{sup +} resonance at {approx}600 keV above the proton threshold in {sup 18}Ne is found to have a partial width {Gamma}{sub {gamma}} = 56 {+-} 24(stat) {+-} 30(sys) meV, in reasonable agreement with the theoretically predicted width. A 2{sigma} upper limit on the direct capture of S(E) = 65 keV b is determined at an energy of 800 keV. Experimental techniques and astrophysical implications are discussed.

The {sup 18}Ne({alpha},p){sup 21}Na reaction plays a crucial role in the ({alpha},p) process, which leads to the rapid proton capture process in x-ray bursts. The reaction rate depends upon properties of {sup 22}Mg levels above the {alpha} threshold at 8.14 MeV. Despite recent studies of these levels, only the excitation energies are known for most with no constraints on the spins. We have studied the {sup 24}Mg(p,t){sup 22}Mg reaction at the Oak Ridge National Laboratory (ORNL) Holifield Radioactive Ion Beam Facility (HRIBF), and by measuring the angular distributions of outgoing tritons, we provide some of the first experimental constraints on the spins of astrophysically important {sup 18}Ne({alpha},p){sup 21}Na resonances.

The rate of the (17)F(p,gamma)(18)Ne reaction is important in various astrophysical events. A previous (17)F(p,p)(17)F measurement identified a 3;{+} state providing the strongest resonance contribution, but the resonance strength was unknown. We have directly measured the (17)F(p,gamma)(18)Ne reaction using a mixed beam of (17)F and (17)O at ORNL. The resonance strength for the 3;{+} resonance in (18)Ne was found to be omegagamma = 33 +/- 14(stat) +/-1 7(syst) meV, corresponding to a gamma width of Gamma_{gamma} = 56 +/- 24(stat) +/- 30(syst) meV. An upper limit on the direct capture of S(E)

There are a number of astrophysical environments in which the path of nucleosynthesis proceeds through proton-rich nuclei. These nuclei have traditionally not been available as beams, and thus proton-capture reactions on these nuclei could only be studied indirectly. At the Holifield Radioactive Ion Beam Facility (HRIBF), some of the first direct measurements of (p,\( \gamma\)) cross-sections on radioactive beams have been made. The Daresbury Recoil Separator (DRS) has been used to separate the recoils of interest from the unreacted primary beam and identify them in an isobutane-filled ionization counter. First data from 17F (p,\( \gamma\)18Ne and 7Be (p,\( \gamma\)8B measurements are presented.

The rate of the 17F(p,γ)18Ne reaction is of significant importance in astrophysical events like novae and x‐ray bursts. A 3+ state in 18Ne predicted to dominate the rate was found at 599.8 keV using the 17F(p,p)17F reaction [1], but the resonance strength was unknown. For the first time, the 17F(p,γ)18Ne reaction has been measured directly with the Daresbury Recoil Separator, using a mixed beam of radioactive 17F and stable 17O from the HRIBF at ORNL. A γ width was found for the 599.8 keV resonance in 18Ne, and an upper limit on the direct capture S factor was determined at an intermediate energy of 800 keV.

High quality radioactive beams have recently made possible the measurement of (d,p) reactions on unstable nuclei in inverse kinematics, which can yield information on the development of single-neutron structure away from stability, and are of astrophysical interest due to the proximity to suggested r-process paths. The Oak Ridge Rutgers University Barrel Array (ORRUBA) is a new high solid-angular coverage array, composed of two rings of silicon detectors, optimized for measuring (d,p) reactions. A partial implementation has been used to measure (d,p) reactions on nuclei around the N = 82 shell closure.

Neutron transfer reactions were performed in inverse kinematics using radioactive ion beams of 132Sn, 130Sn, and 134Te and deuterated polyethylene targets. Preliminary results are presented. The Q‐value spectra for 133Sn, 131Sn and 135Te reveal a number of previously unobserved peaks. The angular distributions are compatible with the expected lf7/2 nature of the ground state of 133Sn, and 2p3/2 for the 3.4 MeV state in 131Sn.

Neutron transfer (d,p) reaction studies on the N = 50 isotones, 82Ge and 84Se, and A≈130 nuclei, 130,132Sn and 134Te, have been measured. Direct neutron capture cross sections for 82Ge and 84Se (n,γ) have been calculated and are combined with Hauser‐Feshbach expectations to estimate total (n,γ) cross sections. The A≈130 studies used an early implementation of the ORRUBA array of position‐sensitive silicon strip detectors for reaction proton measurements. Preliminary excitation energy and angular distribution results from the A≈130 measurements are reported.

The Versatile Array of Neutron Detectors at Low Energy (VANDLE) is a new array of plastic scintillator bars under development for measurements at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The array is highly modular allowing the configuration of the individual elements to be optimized for particular experimental requirements, such as (d,n) and beta‐delayed neutron‐decay measurements with neutron‐rich rare isotope beams.

The magnitude of the {sup 15}N(n,{gamma}){sup 16}N reaction rate in asymptotic giant branch stars depends directly on the neutron spectroscopic factors of low-lying {sup 16}N levels. A new study of the {sup 15}N(d,p){sup 16}N reaction is reported populating the ground and first three excited states in {sup 16}N. The measured spectroscopic factors are near unity as expected from shell model calculations, resolving a long-standing discrepancy with earlier measurements that had never been confirmed or understood. Updated {sup 15}N(n,{gamma}){sup 16}N reaction rates are presented.

The rate of the (17)F(p,gamma)(18)Ne reaction is important in various astrophysical events. A previous (17)F(p,p)(17)F measurement identified a 3;{+} state providing the strongest resonance contribution, but the resonance strength was unknown. We have directly measured the (17)F(p,gamma)(18)Ne reaction using a mixed beam of (17)F and (17)O at ORNL. The resonance strength for the 3;{+} resonance in (18)Ne was found to be omegagamma = 33 +/- 14(stat) +/-1 7(syst) meV, corresponding to a gamma width of Gamma_{gamma} = 56 +/- 24(stat) +/- 30(syst) meV. An upper limit on the direct capture of S(E)or= 65 keV b was determined at an energy of 800 keV.

The development of high quality radioactive beams has made possible the measurement of transfer reactions in inverse kinematics on unstable nuclei. Measurement of (d,p) reactions on neutron-rich nuclei yield data on the evolution of nuclear structure away from stability, and are of astrophysical interest. Experimentally, (d,p) reactions on heavy (Z=50) fission fragments are complicated by the strongly inverse kinematics, and relatively low beam intensities. Consequently, ejectile detection with high resolution in position and energy, a high dynamic range and a high solid angular coverage is required. The Oak Ridge Rutgers University Barrel Array (ORRUBA) is a new silicon detector array optimized for the measurement of (d,p) reactions in inverse kinematics.

The 82Ge, 84Se, 132Sn, 130Sn, and 134Te (d,p) reactions have been measured with {approx}4-5-MeV-A rare isotope beams and CD2 targets at the HRIBF at ORNL. Energies and spectroscopic strengths have been measured for excitations in 83Ge and 85Se. Direct neutron capture calculations on 82Ge are presented. Preliminary results for single-neutron excitations in 131Sn, 133Sn, and 135Te are reported.

International audience; States in 26Na were populated in the (d, pγ) reaction, induced by bombarding deuterium target nuclei with an intense reaccelerated beam of 25Na ions from the ISAC2 accelerator at TRIUMF. Gamma-rays were recorded in coincidence with protons and used to extract differential cross sections for 21 states up to the neutron decay threshold of 5 MeV. Results for levels below 3 MeV are discussed in detail and compared with shell model calculations and with previous work. The angular distributions of decay gamma-rays were measured for individual states and are compared to theoretically calculated distributions, highlighting some issues for future work.

A new program to measure (d,p) reactions on rare isotopes of fission fragments has been established at Oak Ridge National Laboratory. Initial measurements on N=50 isotones and prospects for Z=50 experiments are reported.

Clustering phenomena in 10Be and 18O were studied by means of resonance elastic scattering of α-particles on 6He and 14C. Excitation functions for α+6He and α+14C were measured and detailed R-matrix analyses of the excitation functions was performed. We compare the experimental results with the predictions of modern theoretical approaches and discuss properties of cluster rotational bands.

The first (d,p) neutron transfer reaction on a neutron-rich r-process nucleus has been measured at the Holifield Radioactive Ion Beam Facility. The {sup 2}H({sup 82}Ge,p){sup 83}Ge reaction was studied by bombarding a 430-{mu}g/cm{sup 2} (CD{sub 2}){sub n} target with a 330-MeV beam of radioactive {sup 82}Ge. The reaction Q value (Q=1.47{+-}0.02 stat. {+-}0.07 sys. MeV) has been measured leading to the first determination of the mass of the N=51 nucleus {sup 83}Ge. Excitation energies, angular distributions, and spectroscopic factors for the first two states of {sup 83}Ge have also been determined.

Two N=51 isotones have been measured using (d,p) reactions in inverse kinematics at the Holifield Radioactive Beam Facility (HRIBF) of Oak Ridge National Laboratory. Additionally, we have performed a test measurement using a stable 124Sn beam in preparation for measurements of the 2H(130,132Sn,p)131,133Sn reactions. Preliminary results for 83Ge and 85Se suggest a 5/2+ ground state and a 1/2+ first excited state for both isotopes, in agreement with systematics for the N=51 isotones. The excitation energy of the first excited state is shown to drop as the proton number is reduced. Proton angular distributions following the 2H(124Sn,p)125Sn reaction show sensitivity to the l‐value of the transfered nucleon and spectroscopic factors are in agreement with previous measurements in normal kinematics.

The d(82Ge,p) reaction has been measured in inverse kinematics at the Holifield Radioactive Ion Beam facility, enabling a study of the evolution of single‐particle structure above the N=50 shell gap for neutron‐rich nuclei.