Total reaction cross sections, , of 20–60A MeV , , and were measured by injecting magnetically separated, focused, monoenergetic, identified secondary beams of those projectiles into a Si detector telescope and measuring their energy-deposition spectra. These ’s, accurate to about 3%, were compared with predictions of optical, strong absorption, and microscopic models. The latter gave the best overall fit to the data, providing long-tailed matter densities were assumed. The best available optical potentials generally overpredicted the data by about 10%. Strong absorption calculations, in which the isospin-dependent term is quite important, were often unsuccessful, especially for projectiles with large neutron excess. Two-neutron removal cross sections were measured for and ; the data were slightly overpredicted by a microscopic model which includes correlation effects for the valence neutrons. Both 2n and 4n removal from were observed, in about a 2:1 ratio. Subtraction analysis of the data indicates that is a good core within and , as is within . © 1996 The American Physical Society.
- Received 1 March 1996
- Published in the issue dated October 1996
© 1996 The American Physical Society