High Magnetic Field Research

A magnetic field is said to possess an energy density which is analogous to the thermal energy density of a gas. When a region of magnetic field is compressed or distorted, its energy content is raised. A magnetic field of 1 megagauss has an energy density of 40 x 10/sup 3/ ergs, or 1000 cal per cc, which is comparable to the chemical energy density of high explosives. The achievement of very high magnetic fields has obvious uses in pure and applied research. In high energy physics, the most common use is that of guiding energetic particles along paths that are more or less strongly curved, depending on the field strength and panticle momentum. An analogy of the magnetic field is given as a two-dimensional in which the flux lines take the place of gas molecules. This analogy becomes exact for systems that are infinite and uniform along the direction of the field. The technological avenues being followed to produce high magnetic fields are reduction of input current requirement by means of a tubular coil wound of insulated wire, use of motional effects in solid tube design with a straight or helical slit, use of motional effects in solidmore » but nonrigid tubes, use of conductive fluids, and reduction of magnetic forces by means of forcefree geometric designs. (B.O.G.)« less