A cryogenic ablation catheter includes a catheter shaft, a balloon and a connector respectively at the catheter shaft proximal and distal ends, a refrigerant delivery tube assembly including a refrigerant delivery tube translatable within the catheter shaft lumen, and a refrigerant delivery element with an outlet located inside the balloon which directs refrigerant outwardly against the balloon at different axial positions as it translates. A cryogenic balloon ablation system includes the cryogenic ablation catheter, a catheter coupler mating with the connector, a linear motion assembly, and a connection line fluidly coupled to a refrigerant fluid source for supplying refrigerant fluid to the refrigerant delivery tube.
