What is size of copper bus bar for 1000 Amps capacity for a current density of 1.2 amps and 1 amp?

The following sizes of bus-bar will have the capacity to handle 1000 amps,

3/16 x 4", 1/4 x 3 1/2", 3/8 x 2 1/2", and 1/2 x 2".