Optical measurement of multi-MA current in ultrahigh magnetic fields explosion generator

The magnetic field amplified in the magnetic explosive generator MC-1 is produced by a closed ring-electric current over the cylindrical metal shell of the generator (A.D. Sakharov, Sov. UFN, vol. 88, no. 4, pp. 3-11, 1966). Values traditionally measured in experiments with MC-1 generators are the initial and amplified magnetic field derivative and integral, sometimes the diameter of an imploding shell (since these measurements are very difficult), and, very rarely, seed current of the initial magnetic field source (mainly to control the state of the power circuit and the initial field source). The paper describes an optical technique for the MC-1 shell total current measurement during initial magnetic flux generation and on its subsequent compression. A similar technique was first implemented in the first American-Russian set of experiments performed at Los Alamos late in 1993, with VNIIEF developed MC-1 cascade generator (C.M. Fowler and B.L. Freeman, LANL Report LA-UR-94-2892, 1994). These are additional measurements to those of the generator basic parameters, which also improve adequacy of the latter and contain data on evolution of the generator´s shell longitudinal section shape during implosion.