Reactions induced beyond the dripline at low energy by secondary beams

Abstract

Reactions induced on protons at low incident energy (3.5 MeV/n) were measured with a 8He beam accelerated by Spiral at Ganil. The particles were detected in the active target Maya, filled with C4H10 gas. The beam was stopped in the detector, so energies from incident beam energy down to detector threshold were covered. Proton elastic scattering, one neutron pick-up (p; d) and (p; t) reactions were observed. In the (p; d) reaction very high cross-sections of the order of 1barn were observed, that could be reproduced using a direct reaction formalism. This is the first time that this strong increase of transfer reaction cross-sections at very low energy predicted for loosely bound systems was observed. Spectroscopic factors are in agreement with a simple shell model configuration. No evidence for a low lying excited state in 7He was found.