  A solid state mechanism for cooling high-current cables is proposed based on
the Ettingshausen effect, i.e. the transverse thermoelectric cooling generated
in magnetic fields. The intense current running in the cable generates a strong
magnetic field around it, that can be exploited by a small current running in a
coating layer made out of a strong "thermomagnetic" material to induce a
temperature difference between the cable core and the environment. Both
analytical calculations and realistic numerical simulations for Bismuth
coatings in typical magnetic fields are presented. The latter yield temperature
drops ~60K and >100K for a single- and double-layer coating respectively. These
encouraging results should stimulate the search for better thermomagnetic
materials, in view of applications such as self-cooled superconducting cables
working at room temperature.
