A stator assembly for an electrical machine , said stator assembly comprising: a pressure vessel ; a substantially cylindrical stator core portion including: a substantially cylindrical yoke portion within the pressure vessel in thermal communication with said pressure vessel to facilitate heat removal from said stator assembly ; a substantially cylindrical teeth portion including a plurality of circumferentially adjacent stator teeth wherein the circumferentially adjacent stator teeth define a plurality of circumferentially adj acent stator winding slots ; the teeth portion includes a plurality of magnetic laminations having a predetermined magnetic permeability such that magnetic flux generation and conduction is facilitated within the stator core portion , and a plurality of thermally conductive laminations having heat transfer properties that facilitate heat removal from the stator core portion more efficiently than the magnetic laminations ; the yoke portion includes a plurality of thermally conductive laminations that are substantially similar to the thermally conductive laminations in the teeth portion ; the stator assembly being characterized in that the axial thickness of the thermally conductive laminations of the yoke portion is different than the axial thickness of the thermally conductive laminations of the teeth portion . a pressure vessel ; a substantially cylindrical stator core portion including: a substantially cylindrical yoke portion within the pressure vessel in thermal communication with said pressure vessel to facilitate heat removal from said stator assembly ; a substantially cylindrical teeth portion including a plurality of circumferentially adjacent stator teeth wherein the circumferentially adjacent stator teeth define a plurality of circumferentially adj acent stator winding slots ; the teeth portion includes a plurality of magnetic laminations having a predetermined magnetic permeability such that magnetic flux generation and conduction is facilitated within the stator core portion , and a plurality of thermally conductive laminations having heat transfer properties that facilitate heat removal from the stator core portion more efficiently than the magnetic laminations ; the yoke portion includes a plurality of thermally conductive laminations that are substantially similar to the thermally conductive laminations in the teeth portion ; the stator assembly being characterized in that the axial thickness of the thermally conductive laminations of the yoke portion is different than the axial thickness of the thermally conductive laminations of the teeth portion . a substantially cylindrical yoke portion within the pressure vessel in thermal communication with said pressure vessel to facilitate heat removal from said stator assembly ; a substantially cylindrical teeth portion including a plurality of circumferentially adjacent stator teeth wherein the circumferentially adjacent stator teeth define a plurality of circumferentially adj acent stator winding slots ; the teeth portion includes a plurality of magnetic laminations having a predetermined magnetic permeability such that magnetic flux generation and conduction is facilitated within the stator core portion , and a plurality of thermally conductive laminations having heat transfer properties that facilitate heat removal from the stator core portion more efficiently than the magnetic laminations ; the yoke portion includes a plurality of thermally conductive laminations that are substantially similar to the thermally conductive laminations in the teeth portion ; the stator assembly being characterized in that the axial thickness of the thermally conductive laminations of the yoke portion is different than the axial thickness of the thermally conductive laminations of the teeth portion . <EOS>