  We report on a new measurement of the strength of the superallowed 0+->0+
transition in the beta-decay of 10C: 10C(0+,g.s.)->10B(0+,1.74MeV)+e+nu. The
experiment was done at the LBNL 88-inch cyclotron using forty seven GAMMASPHERE
germanium detectors. Precise knowledge of this branching ratio is necessary to
compute the superallowed Fermi ft, which gives the weak vector coupling
constant and the u to d element of the Cabibbo-Kobayashi- Maskawa quark mixing
matrix.
