Coils for the Production of High-Intensity Pulsed Magnetic Fields

Abstract

The problem of producing extremely high magnetic fields is briefly reviewed in the light of modern technique. The design, performance, and application of a pulsed-field system capable of more than 750 000 gauss at room temperature is described. The coil comprises a suitably supported, machined, beryllium-copper, helix having an inside diameter of 316 in. and a length of about ½ in.; it is connected directly to a 2000 μf, 3 kv bank of surge capacitors by means of a triggered-spark gap. The discharge is oscillatory with a half-period of 120 μsec. Detailed design data and performance characteristics are presented for a large range of similarly constructed coils which afford increased volume and field uniformity at a sacrifice in field intensity. A coil providing transverse access to the field and one suitable for operation in liquid helium are also described. Characteristics of less durable coils constructed of a single strip of conductor are discussed. Brief comments on applications to a broad range of solid-state experiments and some inherent limitations are presented. Finally, the production of modulated pulsed fields, unidirectional fields, and the feasibility of extending the pulse duration are discussed.