  The design, construction, and characterization of the Multi-Sampling
Ionization Chamber, MuSIC@Indiana, are described. This detector provides
efficient and accurate measurement of the fusion cross-section at near-barrier
energies. The response of the detector to low-intensity beams of $^{17,18}$O,
$^{19}$F, $^{23}$Na, $^{24,26}$Mg, $^{27}$Al, and $^{28}$Si at E$_{lab}$ =
50-60 MeV was examined. MuSIC@Indiana was commissioned by measuring the
$^{18}$O+$^{12}$C fusion excitation function for 11 $<$ E$_{cm}$ $<$ 20 MeV
using CH$_{4}$ gas. A simple, effective analysis cleanly distinguishes proton
capture and two-body scattering events from fusion on carbon. With
MuSIC@Indiana, measurement of 15 points on the excitation function for a single
incident beam energy is achieved. The resulting excitation function is shown to
be in good agreement with literature data
