There is no strict definition of the term High Magnetic Field . It has been proposed to use this term for magnetic fields that are technically difficult to generate and therefore need special equipment or large resources. Static fields above 20 T are apparently high magnetic fields in this sense, but in the case of pulsed field 40 T is easy to obtain and any field lower than this approximate limit should not be considered as high . When a static field is used for materials processing, even 10 T is considered as high because the long-term use of a conventional superconducting magnet is difficult. Recently, there has been much technical progress in producing high mag­ netic fields, both pulsed and static; in large part this is due to the devel­ opment of new materials. Complicated poly-helix coils are now replaced by simple Bitter coils made with plates of CuAg alloy with high strength and high conductivity; these are used in both water-cooled and hybrid magnets (now up to 45 Tat NHMFL, the US National High Magnetic Field Labora­ tory at Tallahassee, Florida). By using CuAg wire, a nondestructive pulsed field record of 80 T has been achieved at Osaka University. For daily use in experiments, 70-75 T should soon become available. Major facilities for static high fields worldwide are planning to generate fields over 40 T by increasing the electric power. On the other hand, the use of static high magnetic fields is expanding.

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