Pulsed power hydrodynamics: applying pulsed power and high magnetic fields to produce extreme conditions

Summary form only given. Pulsed power hydrodynamics is a new application of pulsed high magnetic fields to explore advanced hydrodynamics, instabilities, fluid turbulences, and material properties in a highly precise, controllable environment at the extremes of pressure and material velocity. The Atlas facility designed and built by Los Alamos is the world´s first and only laboratory pulsed power system designed specifically to explore this relatively new family of pulsed power applications. Constructed in 2000 and commissioned in August 2001, Atlas is a 24-MJ high-performance capacitor bank delivering up to 30-megamperes with a current risetime of 5-6-musec. The high-precision, cylindrical, imploding liner is the tool most frequently used to convert electromagnetic energy into the hydrodynamic (particle kinetic) energy needed to drive the experiments. For typical liner parameters with an initial radius of 5-cm, the peak current of 30-MA delivered by Atlas results in magnetic fields just over 1-MG outside the liner prior to implosion. During the 5 to 10-musec implosion, the field outside the liner rises to several MG in typical situations. At these fields the rear surface of the liner is melted and it is subject to a variety of complex behaviors including: diffusion dominated and/or melt wave field penetration and heating; magneto Rayleigh-Taylor sausage mode behavior at the liner/field interface; and azimuthal asymmetry due to perturbations in current drive. The first Atlas liner implosion experiments were conducted in September 2001 and 16 experiments were conducted in the first year of operation. Immediate applications of the new pulsed power hydrodynamics techniques include material property topics such as: exploration of material strength at high rates of strain, material failure including fracture and spall, and-interfacial dynamics at high relative velocities and high interfacial pressures. A variety of complex hydrodynamic geometries will be explored and ex- - periments will be designed to explore unstable perturbation growth and transition to turbulence. Longer term applications include the study of the hydrodynamics and properties of strongly coupled plasmas and equation of state of materials at pressures above 10 Mbar. This paper will provide an overview of the Atlas system and of the range of problems to which pulsed power hydrodynamics can be applied and the issues associated with these techniques