A cryogenic submerged multi-stage pump assembly , comprising: a vertically oriented pump shaft ; an electrical motor comprising a rotor attached to the pump shaft and a stator disposed about the rotor , wherein the electrical motor comprises a permanent magnet electrical motor; a first-stage impeller assembly (STAGE 1) comprising a first impeller attached to the pump shaft , the first impeller configured to move a cryogenic fluid from a first impeller inlet to a first impeller outlet when the pump shaft is rotated by the electric motor , and a first impeller housing disposed about the first impeller and configured to channel the cryogenic fluid once it exits the first impeller outlet ; and a second-stage impeller assembly (STAGE 2) comprising a second impeller attached to the pump shaft , the second impeller configured to move the cryogenic fluid from the first impeller housing to a second impeller inlet and then to a second impeller outlet when the pump shaft is rotated by the electric motor , and a second impeller housing disposed about the second impeller and configured to channel the cryogenic fluid once it exits the second impeller outlet to a discharge tube or discharge outlet ; wherein the first-stage impeller assembly (STAGE 1) is disposed below the second-stage impeller assembly (STAGE 2), and where the second-stage impeller assembly (STAGE 2) is disposed below the permanent magnet electrical motor ; wherein the rotor comprises four magnetic poles, characterized in that the pump shaft comprises a magnetic stainless steel shaft, and in that the magnetic poles are secured to the magnetic stainless steel shaft by magnetic force and by a circumferential non-magnetic sleeve that prevents centrifugal forces of rotation from detaching the poles during motor operation. a vertically oriented pump shaft ; an electrical motor comprising a rotor attached to the pump shaft and a stator disposed about the rotor , wherein the electrical motor comprises a permanent magnet electrical motor; a first-stage impeller assembly (STAGE 1) comprising a first impeller attached to the pump shaft , the first impeller configured to move a cryogenic fluid from a first impeller inlet to a first impeller outlet when the pump shaft is rotated by the electric motor , and a first impeller housing disposed about the first impeller and configured to channel the cryogenic fluid once it exits the first impeller outlet ; and a second-stage impeller assembly (STAGE 2) comprising a second impeller attached to the pump shaft , the second impeller configured to move the cryogenic fluid from the first impeller housing to a second impeller inlet and then to a second impeller outlet when the pump shaft is rotated by the electric motor , and a second impeller housing disposed about the second impeller and configured to channel the cryogenic fluid once it exits the second impeller outlet to a discharge tube or discharge outlet ; wherein the first-stage impeller assembly (STAGE 1) is disposed below the second-stage impeller assembly (STAGE 2), and where the second-stage impeller assembly (STAGE 2) is disposed below the permanent magnet electrical motor ; wherein the rotor comprises four magnetic poles, characterized in that the pump shaft comprises a magnetic stainless steel shaft, and in that the magnetic poles are secured to the magnetic stainless steel shaft by magnetic force and by a circumferential non-magnetic sleeve that prevents centrifugal forces of rotation from detaching the poles during motor operation. <EOS>