Reaction cross-section and reduced strong absorption radius measurements of neutron-rich nuclei in the vicinity of closed shells [formula omitted] and [formula omitted

Abstract

The energy-integrated reaction cross-sections of several neutron-rich nuclei ( 17−22N, 19−24O, 21−27F, 23−30Ne, 26−33Na, 28−35Mg, 31−38Al, 33−40Si, 36−42P, 39−44S, 42−45Cl, 45,46Ar), measured at intermediate energy (30–65 A MeV), via direct method, are presented. Silicon detectors have been used as the active target as well as for particles identification. The reduced strong absorption radii r 0 2 are extracted and compared to the data available from the literature. New measurements for 19 nuclei ( 27F, 27,30Ne, 33Na, 28,34–35Mg, 36−38Al, 38−40Si, 41−42P, 42−44S, 45Cl) are revealed. From the study of the isospin dependence of the reduced strong absorption radius, a new quadratic parameterisation of the nuclear radii in the closed shell regions N = 8 and N = 28 , is proposed. According to this parameterisation, the proton/neutron rich nuclei skin effect is well described and a new anomalous structure: halo-structure or large deformation is suggested for 35Mg and 44S nuclei.