B. Harss

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.

Experiments with a radioactive 56Ni beam

Abstract A technique for producing a high-quality radioactive 56 Ni (T 1/2 =6.1 d ) beam via the two-accelerator method has been developed. Beam intensities of 2×10 7 56 Ni/s were extracted from the ion source and 2×10 4 56 Ni/s were delivered to the target. For a study of neutron transfer reactions in inverse kinematics, a high-efficiency detection system was built consisting of a large solid angle (2.8 sr), high-granularity Si detector array for measuring the outgoing protons in coincidence with the heavy reaction products identified with respect to mass A and nuclear charge Z in the focal plane of a recoil mass separator.

Experimental study of the {sup 56}Ni({sup 3}He,d){sup 57}Cu reaction in inverse kinematics

Measurements of ({sup 3}He,d) reactions can provide information on the proton widths of states that play a role in astrophysically important (p,{gamma}) reactions. We report on the first study of the ({sup 3}He,d) reaction in inverse kinematics with a {sup 56}Ni (T{sub 1/2}=6.1 d) ion beam. The Q-value resolution of {approx} keV achieved in this experiment was sufficient to separate the transitions populating the ground state and the 1/2{sup -}-5/2{sup -} doublet at E{sub x}{approx}1.1 MeV in {sup 57}Cu. Prospects for similar ({sup 3}He,d) experiments with improved energy resolution are also discussed.

Experiments with radioactive beams at ATLAS

Various beams of short- and long-lived radioactive nuclei have recently been produced at the ATLAS accelerator at Argonne National Laboratory, using either the so-called In-Flight or the Two-Accelerator method. The production techniques, as well as recent results with 44Ti(T1/2=60y) and 17F(T1/2=64s) beams, which are of interest to nucleosynthesis in supernovae and X-ray bursts, are discussed.