Measuring the fusion cross-section of $^{39,47}$K + $^{28}$Si at near barrier energies*

The outer crust of an accreting neutron star provides an interesting environment for nuclear reactions to occur. In particular, the enhancement of fusion between neutron-rich nuclei relative to their $\beta$-stable counterparts has been suggested as a trigger for an X-ray superburst. Recently, nuclei in the mass range of A=20-40 have been proposed as the most likely candidates for this process. To investigate this question, comparing the fusion excitation functions for both neutron-rich and $\beta$-stable nuclei at energies near the fusion barrier is necessary. The development of a $^{47}$K radioactive beam at NSCL’s ReA3 facility makes such a comparison possible for the first time. An approved experiment to measure the fusion excitation functions for $^{39,47}$K + $^{28}$Si will be described. This experiment utilizes a technique optimized for measuring the total fusion cross-section of reactions involving low-intensity (10$^{3}$ - 10$^{6}$ ions/s) radioactive beams. In addition, protons and $\alpha$ particles emitted by the compound nucleus as it de-excites are measured. Preliminary results will be presented.