Production of radioactive ion beams using the in-flight technique

Reactions with a heavy projectile incident on a light target can be used for the efficient in-flight production of secondary radioactive beams. An overview of this technique is given using data on 17F beams produced via the p(17O, 17F)n and d(16O, 17F)n reactions. With primary 16,17O beam currents of 100 pnA, intensities of up to 2×106 17F/s on target were achieved. Using this beam, the p(17F, α) 14O reaction was measured

Fusion Cross Sections for the Proton Drip Line Nucleus 17F at energies below the coulomb barrier

The fusion-fission cross section for the system 17F + 208Pb involving the drip line nucleus 17F has been measured at energies in the vicinity of the Coulomb barrier. No enhancement of the fusion-fission yields due to breakup or to a large interaction radius was observed

Experimental study of the Ni56(He3,d)Cu57 reaction in inverse kinematics

Measurements of (He3,d) reactions can provide information on the proton widths of states that play a role in astrophysically important (p,γ) reactions. We report on the first study of the (He3,d) reaction in inverse kinematics with a Ni56(T1/2=6.1 d) ion beam. The Q-value resolution of ~keV achieved in this experiment was sufficient to separate the transitions populating the ground state and the 1/2 - 5/2- doublet at Ex~1.1 MeV in Cu57. Prospects for similar (He3,d) experiments with improved energy resolution are also discussed

Stellar reactions with short-lived nuclei: 17F(p,α)14O

A method has been developed that can provide beams of many short-lived nuclei of interest in nucleosynthesis along the rp process path. With a 17F beam (T1/2=64s) the excitation function of the 17F(p, α)14O reaction was measured to determine properties of excited states in 18Ne. These states influence the rate of the 14O(α, p)17F reaction which is important for understanding energy generation and nucleosynthesis in x-ray bursts. The present direct measurements yield a pattern of resonances and cross sections which differ substantially from previous estimates

The 44Ti(α, p) reaction and its implication on the 44Ti yield in supernovae

Cross sections for the 44Ti(α, p)47V reaction which significantly affects the yield of 44Ti in supernovae were measured in the energy range 5.7MeV ≤ Ec.m. ≤ 9 MeV, using a beam of radioactive 44Ti. The cross sections and the deduced astrophysical reaction rates are larger than the results from theoretical calculations by about a factor of 2. The implications of this increase in the reaction rate for the search of supernovae using space-based gamma detectors are discussed

Widths of astrophysically important resonances in 18Ne

The astrophysically important reaction 14O(α,p)17F has been studied through a measurement of the time-inverse p(17F,α)14O reaction using a radioactive 17F beam. Resonance parameters for several states above an excitation energy of 7 MeV in 18Ne have been obtained. Through a measurement of the partial widths for elastic and inelastic proton scattering, it was determined that for these resonances the contribution of the 14O(α,p)17F* branch populating the first excited state in 17F is small. The results indicate that the contribution of resonances above Ex=7 MeV to the astrophysical (α,p) reaction rate is smaller than was previously assumed

Study of the 56Ni(d, p)57 Reaction and the Astrophysical 56Ni(p, γ)57Cu Reaction Rate

The single-particle character of states outside the doubly magic (radioactive) nucleus 56Ni has been determined through a measurement of the (d, p) neutron transfer reaction using inverse kinematics. From the spectroscopic factors of the low-lying states in 57Ni, the astrophysically interesting yield for the 56Ni(p, γ) reaction to the mirror nucleus 57Cu has been calculated, utilizing charge symmetry. The rate for this reaction in the temperature range typical of novae, supernovae, and x-ray bursts is found to be more than 10 times higher than previously assumed

The production and transport of radioactive {sup 17}F at ATLAS for research

A secondary beam of radioactive {sup 17}F was produced at the ATLAS accelerator and delivered to an experimental target station with an intensity of as much as 5{circ}10{sup 5} ions/s for use in the research program. Beams of {sup 17}F were produced via the p({sup 17}O, {sup 17}F)n or d({sup 16}O, {sup 17}F)n reactions by bombarding a gas-filled cell with up to 300 pnA beams of {sup 17}O or {sup 16}O from the ATLAS superconducting linac. The gas target, with HAVAR windows, was maintained at pressures as high as 500 Torr. The beam quality was dominated by small-angle scattering in the gas cell windows, by the reaction kinematics and beamline acceptance. Detailed beam parameters are presented. Plans for relocation of the target to allow improved capture efficiency and acceleration or de-acceleration of the secondary beam will also be discussed

The first production and transport of radioactive {sup 17}F at ATLAS for research

A secondary beam of radioactive {sup 17}F was produced at the ATLAS accelerator and delivered to an experimental target station with an intensity of at least 2 x 10{sup 5} particles per second for use in the research program. The beam was produced through the p({sup 17}O, {sup 17}F)n inverse reaction by bombarding a hydrogen gas target with 250 particle nA of 83 MeV {sup 17}O from the ATLAS superconducting linac. The gas target was maintained at a pressure of 300 Torr and a temperature of 257 K. Beam quality was dominated by multiple scattering in the gas cell windows and by the reaction kinematics and beamline acceptance for energy spread