A cryogenic ablation catheter (12) includes a catheter shaft (16), a balloon (24) and a connector (22) respectively at the catheter shaft proximal and distal ends (18, 20), a refrigerant delivery tubeassembly including a refrigerant delivery tube (30) translatable within the catheter shaft lumen, and a refrigerant delivery element (36, 44) with an outlet (40) located inside the balloon which directs refrigerant outwardly against the balloon at different axial positions as it translates. A cryogenic balloon ablation system (10) includes the cryogenic ablation catheter, a catheter coupler (78)mating with the connector, a linear motion assembly (120), and a connection line (118) fluidly coupled to a refrigerant fluid source (100) for supplying refrigerant fluid to the refrigerant delivery tube.