I'd sudjest that u shouldn't chase off the coons, they r known to attack, & they can kill a large dog.

A friend of mine put mothballs about 6 feet around the cage to keep cats away, it worked for the cats, u can try it for coons.

At my college, they put up rows of long nails (not pointed) along the edges of the roofs & on window ledges, so birds wont land on it & poop everywhere.
You can try to make a removible one & put it around & ontop of the cage at night, the coons arn't stupid enough to jump on it, they r smart. Give it a shot & tell us if it worked.