A. Morsad

A radioactive beam facility using a large superconducting solenoid

Abstract A facility for producing well-focussed (~ 5 mm diameter) secondary beams of ≤ 20 MeV 6 He, 7 Be, 8 Li, and similar ions has been implemented. The heart of the apparatus is a superconducting solenoid operating in an asymmetric lens configuration, with large solid angle (dΩ ≥ 100 msr) for the collection of reaction products. A beam of 15-MeV 8 Li ions ( ΔE ≤ 0.6 MeV) of intensity 5 × 10 4 ions/s, produced via the 9 Be( 7 Li, 8 Li) 8 Be reaction, was scattered from targets of CH 2 , CD 2 , 9 Be, 12 C, 27 l, and 197 Au. Elastic scattering and ( 8 Li, 7 Li) reaction products are unambiguously identified. Preliminary results of measurements on the 2 H( 8 Li, 9 Be)n reaction, as well as the status of a project to upgrade the 8 Li beam intensity to ≥ 1 ×10 6 ions/s, are reported. ft]∗|Permanent address: Physics Department, Oberlin College, Oberlin, OH 44074, USA.

Production and use of 6He, 7Be, 8Li, 12B and metastable nuclear beams

Abstract A low energy (few MeV/nucleon), modest flux ( 10 4 −10 7 s ) radioactive nuclear beam (RNB) facility has been in operation for approximately three years at the University of Notre Dame Van de Graaff accelerator. This facility utilizes a compact superconducting solenoid lens, designed at the University of Michigan, with adjustable apertures to produce momentum-analyzed secondary beams via the direct transfer and other methods. Useable beams of 6He, 7Be, 8Li, 12B, 18F and to our knowledge the first isomeric beam, 18mF, have been produced and a first generation of RNB experiments has been successfully completed.

Reaction rates for 8Li(p, α) and 8Li(p, n, α) and their effect on primordial nucleosynthesis

Abstract Differential-cross-section data are presented for the 8 Li(p, α) 5 He reaction at 1.5 MeV center-of-mass energy, measured with a (radioactive) 8 Li beam. The data are used to calculate one of the terms of the thermonuclear reaction rate for destruction of 8 Li. In addition, other data are used to estimate the total reaction rate for p+ 8 Li, which is found to be comparable to that used in previous calculations of abundances from primordial nucleosynthesis.

Production and use of radioactive 7Be beams

Abstract A beam of 7 Be 4+ ions having E = 20.7 MeV and intensity 1.5×10 4 s −1 has been produced via the 1 H ( 10 B, 7 Be) 4 He reaction. The beam had an energy resolution of 1.0 MeV FWHM, 1 cm spot size, and 3° angular divergence. The effect of a z -moveable secondary stop on beam purity was investigated. A 7 Be 4+ ion beam of E = 15.2 MeV, intensity 5×10 3 s −1 , and similar energy resolution and emittance characteristics was produced via 12 C( 3 He, 7 Be) 8 Be reaction. The maximum feasible 7 Be secondary beams from these two reactions are extrapolated to be 5×10 5 s −1 , respectively. Elastic scattering data for 7 Be from Au and C targets are presented as an example of the use of this radioactive beam in secondary scattering experiments.