0000000000343891
AUTHOR
L. Johannsen
The decay of $^{31}$Ar
10 pages, 1 table, 4 figures.
Emission of neutrons and the neutron halo of $^{11}$Li
The matter distribution of the neutron drip-line nuclei has been a subject of intense interest since pioneering radioactive-beam experiments at Berkeley1). Unusually large interaction cross-sections measured at relativistic energies for 11Li,14Be and 17B nuclei were translated into effective matter radii. It was found that these were significantly larger than for other p-shell nuclei. In particular, the root-mean-square (rms) mass radius of 11Li was found to be 3.2fm, which was considerably larger than the 2.4fm radius of 9Li. At the same time, no signatures for significant deformation of 11Li were found in measurements of electric quadrupole moment by means of laser spectroscopy2).
Two-neutron removal reactions for very neutron-rich nuclei
Abstract The two-neutron removal reactions of beams of 11 Li, 14 Be and 8 He upon Be, Ni and Au targets were studied at 30 MeV/u. The cross sections and the neutron forward angular distributions were measured; they correlate strongly with the two-neutron separation energy of the projectile. Even though the coverage of the neutron detectors was limited, a rough neutron-neutron distribution could be extracted. A simplified interpretation of the data is presented.
Neutron momentum distributions from "core break-up" reactions of halo nuclei
Neutron angular distributions from violent break-up reactions of Li-11 and Be-11 have been measured at 28 MeV/u and 280 MeV/u and at 41 MeV/u and 460 MeV/u, respectively. The derived neutron momentum distributions show a narrow component in transverse momentum that is within uncertainties independent of beam energy and target charge. This component is suggested to be simply related to the momentum distribution of the loosely bound halo neutron(s) in the projectiles.
Dissociation of 8He into 6He + n + X at 240 MeV/u
4 pages, 3 figures, 2 tables.
First observation of beta-delayed deuteron emission
5 pages, 2 figures.
Longitudinal and transverse momentum distributions of 9Li fragments from break-up of 11Li
7 pages, 3 figures, 1 table.