Confinement of cosmic rays in molecular clouds

The consequences of cosmic ray production by a supernova in a molecular cloud are discussed. Self-trapping problems for a higher flux of cosmic rays in a molecular cloud are focused on. The column density of molecular clouds is probably too high to explain the majority of galactic cosmic ray sources, even allowing for fortuitous asymmetry in the placement of the supernova in the cloud, however, measurements of antiproton flux suggest that some cosmic ray sources do have a high column density. The large predicted gamma-ray luminosity of such a cloud invites comparison with COS-B sources.