  The absolute cross section of the $^{13}$C($\alpha$,n)$^{16}$O reaction has
been measured at E$_{\alpha}$ = 0.8 to 8.0 MeV with an overall accuracy of 4%.
The precision is needed to subtract reliably a background in the observation of
geo-neutrinos, e.g. in the KamLAND detector.
