Recent astrophysical measurements at NSCL

The A1200 projectile fragment separator at the NSCL has been used to produce secondary beams for a series of experiments with astrophysically interesting nuclei far from stability. Studies of A≤20 nuclei include measurements of the β-decay branching ratios of 15B, β-delayed neutron emission from 18N and 17,18C, and β-delayed proton emission from 20Mg. In the 60<A<100 region, several experiments have been performed to map out the proton drip-line. By measuring the half-lives and binding energies of nuclei such as 65As and 69Br, the path and extent of the rapid proton capture (rp) process can be determined. Recently the performance of the A1200 separator was enhanced by installing a quadrupole doublet just upstream of the target position. The smaller beam spot size provides a larger brightness for secondary beams and a higher resolution for the chromatic modes. A summary of some recent experiments and a description of the separator upgrade will be presented. (orig.)