A low-energy compact electron beam irradiator for core-loss reduction of silicon steel

A new compact, low-energy electron beam irradiator has been developed. The core loss of silicon steels can be reduced by the magnetic-domain refinement method. The irradiator was developed for the application of core-loss reduction using the method. The beam energy of the irradiator can be varied from 35 to 80 keV and the maximum current is 3 mA. The irradiation area is designed to be 30/spl times/30 mm/sup 2/ now and will be upgraded to 30/spl times/150 mm/sup 2/ using a scanning magnet and scanning cone. The electron beam generated from 3 mm diameter LaB/sub 6/ is extracted to the air for the irradiation of the silicon steels in the air. A special irradiation port was developed for this low-energy irradiator. A havar foil with 4.08 /spl mu/m thickness were used for the window and a cold air-cooling system keeps the foil structure by removing heat at the window. The irradiator system and its operation characteristics are discussed.