First Measurement of a Weak r-Process Reaction on a Radioactive Nucleus

This Letter reports on the first cross-section measurements for the ^{94}Sr(α,n)^{97}Zr and ^{86}Kr(α,n)^{89}Sr reactions. In particular, our measurement of ^{94}Sr(α,n)^{97}Zr is the first weak r-process reaction cross section obtained using a radioactive ion beam. This experiment was enabled by the use of novel solid helium targets, comprised of silicon thin films with high helium incorporation obtained via a sputtering technique. Yield …