US/Russian collaboration in high-energy-density physics using high-explosive pulsed power: ultrahigh current experiments, ultrahigh magnetic field applications, and progress toward controlled thermonuclear fusion

A collaboration has been established between the All-Russian Scientific Research Institute of Experimental Physics (VNIIEF) and the Los Alamos National Laboratory (LANL), the two institutes which designed the first nuclear weapons for their respective countries. In 1992, when emerging governmental policy in the United States and Russia began to encourage "lab-to-lab" interactions, the two institutes quickly recognized a common interest in the technology and applications of magnetic flux compression, the technique for converting the chemical energy released by high-explosives into intense electrical pulses and intensely concentrated magnetic energy. In a period of just over three years, the two institutes have performed more than fifteen joint experiments covering research areas ranging from basic pulsed power-technology to solid-state physics to controlled thermonuclear fusion. Using magnetic flux compression generators, electrical currents ranging from 20 to 100 MA were delivered to loads of interest in high-energy-density physics. A 20-MA pulse was delivered to an imploding liner load with a 10-90% rise time of 0.7 /spl mu/s. A new, high-energy concept for soft X-ray generation was tested at 65 MA. More than 20 MJ of implosion-kinetic energy was delivered to a condensed matter imploding liner by a 100-MA current pulse. Magnetic flux compressors were used to determine the upper critical field of a high-temperature superconductor and to create pressure high enough that the transition from single particle behavior to quasimolecular behavior was observed in solid argon. A major step was taken toward the achievement of controlled thermonuclear fusion by a relatively unexplored approach known in Russia as MAGO (MAGnitnoye Obzhatiye, or "magnetic compression") and in the United States as MTF (Magnetized Target Fusion). Many of the characteristics of a target plasma that produced 10/sup 13/ fusion neutrons have been evaluated. Computational models of the target plasma suggest that the plasma is suitable for subsequent compression to fusion conditions by an imploding pusher.