Tsutomu Iimura

Development of a high performance core snubber for high power neutral beam injectors

A high performance core snubber using Fe-based soft magnetic alloys composed of ultrafine grain structure cores has been developed to protect an ion source accelerator from electrical breakdowns. Dimension of each core is 900 mm in outer diameter, 400 mm in inner diameter, and 25.4 mm in thickness. Basic characteristics of the core has been investigated and confirmed that the core has a saturation magnetic flux density of 1.35 T with a high relative permeability of about 3500 for a high frequency pulse of 1 MHz. A total magnetic flux of the core snubber is 0.15 Wb with 13 cores and a biasing current. The size of the core snubber could be reduced to about 1/3 from the conventional one composed of Ni–Zn ferrite cores.