by air blown through jacket 40 as shown in fig1 3 compressed air for cooling inductor 10 may be fed into and out of jacket 40 via air inlet 42 and air outlet 44 referring to fig4 and 5 an other embodiment of an electromagnetic pump constructed in accordance with the present invention is shown pump 300 includes a magnetic circuit or inductor 310 and a helical channel 350 inductor 310 may preferably include ferroceramic elements 320 and a plurality of rmf excitation coils 330 made of any suitable type of thermo stable ceramic boxes for example inside the boxes helical channels may be provided and filled with solid or liquid metal whose melting temperature is lower than the temperature of the lining surrounding the inductor and whose boiling temperature is higher than the temperature of the lining electrodes for electric current supply are preferably fixed at the ends of the helical channel in other embodiments of the present invention inductor 310 may be made in the form of boxes of thin carbon steel filled with iron or cobalt powder for example helical channel 350 may preferably include a pipe 360 similar to pipe 60 of fig1 3 having a longitudinal axis 365 and a helical rod 370 similar to.