  The cross sections of the 162Er(a,g,)166Yb and 162Er(a,n)165Yb reactions have
been measured for the first time. The radiative alpha capture reaction cross
section was measured from Ec.m. = 16.09 down to Ec.m. = 11.21 MeV, close to the
astrophysically relevant region (which lies between 7.8 and 11.48 MeV at 3 GK
stellar temperature). The 162Er(a,n)165Yb reaction was studied above the
reaction threshold between Ec.m. = 12.19 and 16.09 MeV. The fact that the
162Er(a,g)166Yb cross sections were measured below the (a,n) threshold at first
time in this mass region opens the opportunity to study directly the a-widths
required for the determination of astrophysical reaction rates. The data
clearly show that compound nucleus formation in this reaction proceeds
differently than previously predicted.
