A radial counter flow jet gas cooling system for a rotor of a dynamoelectric machine, said rotor comprising: a plurality of conductor bars axially positioned about a centering pin ; said radial counter flow jet gas cooling system comprising: a plurality of axial inlet ducts ; a plurality of radial outlet ducts in communication with the plurality of axial inlet ducts ; the plurality of axial inlet ducts and the plurality of radial outlet ducts being respectively positioned about and made in a plurality of the conductor bars ; an axial subslot positioned beneath the plurality of conductor bars ; and a radial flow duct in communication with the axial subslot , with the axial inlet ducts , and with a first radial outlet duct next to the centering pin , said radial flow duct extending along the centering pin ; wherein the cooling system is configured for a cooling gas to pass through the axial inlet ducts and the radial outlet ducts to cool the plurality of the conductor bars , as well as in series through the axial subslot and the radial flow duct , in a counter flow direction into the plurality of axial inlet ducts , and to be exhausted via a first radial outlet duct next to the centering pin to cool the centering pin . a plurality of conductor bars axially positioned about a centering pin ; said radial counter flow jet gas cooling system comprising: a plurality of axial inlet ducts ; a plurality of radial outlet ducts in communication with the plurality of axial inlet ducts ; the plurality of axial inlet ducts and the plurality of radial outlet ducts being respectively positioned about and made in a plurality of the conductor bars ; an axial subslot positioned beneath the plurality of conductor bars ; and a radial flow duct in communication with the axial subslot , with the axial inlet ducts , and with a first radial outlet duct next to the centering pin , said radial flow duct extending along the centering pin ; wherein the cooling system is configured for a cooling gas to pass through the axial inlet ducts and the radial outlet ducts to cool the plurality of the conductor bars , as well as in series through the axial subslot and the radial flow duct , in a counter flow direction into the plurality of axial inlet ducts , and to be exhausted via a first radial outlet duct next to the centering pin to cool the centering pin . a plurality of axial inlet ducts ; a plurality of radial outlet ducts in communication with the plurality of axial inlet ducts ; the plurality of axial inlet ducts and the plurality of radial outlet ducts being respectively positioned about and made in a plurality of the conductor bars ; an axial subslot positioned beneath the plurality of conductor bars ; and a radial flow duct in communication with the axial subslot , with the axial inlet ducts , and with a first radial outlet duct next to the centering pin , said radial flow duct extending along the centering pin ; wherein the cooling system is configured for a cooling gas to pass through the axial inlet ducts and the radial outlet ducts to cool the plurality of the conductor bars , as well as in series through the axial subslot and the radial flow duct , in a counter flow direction into the plurality of axial inlet ducts , and to be exhausted via a first radial outlet duct next to the centering pin to cool the centering pin . <EOS>