COSMIC: a Compton telescope all-sky monitor for low-energy gamma-ray astronomy

The highly transient nature of cosmic low-energy gamma-ray sources offers unique insight into the astrophysics of extreme processes. Sensitive, long-term, all-sky monitoring is required to make sense of the variable emission. Instrumentation for such observations must have the combination of large effective collection area, wide field-of-view and good angular resolution. Recent advances in position-sensitive detectors and associated electronics make it possible to consider a multi-scatter Compton telescope, combined with a coded mask, as an all-sky monitor in the energy range ~10 keV to a few MeV. We present simulations of various configurations of such an instrument and show that it can provide a substantial improvement over other sky monitor strategies in this energy regime