Modeling and analysis of magnetic screening and other resistive sheath structure of wires in the Sanford effect range with improved conductivity models

Summary form only given, as follows. Because of array stability interest, individual Al wires in the range r=6 to 12 /spl mu/m and I/sub max/=8/spl times/10/sup 4/ to 1.6/spl times/10/sup 5/ Amp are studied by simulation with RAVEN and ALEGRA and by analysis, using I(t) forms of the Sandia Saturn generator both with and without prepulses. Qualitatively improved conductivities (/spl sigma/) are employed in the modeling. Radial motion of the expanded wires is found dominated by resistive quasi-static (RQS) magnetic field behavior (skin depths exceeding wire dimensions) because /spl sigma/ is greatly reduced by the Mott transition, giving approximately E/sub z/(r)=const. Then J(r) and Joule heating /spl sim//spl sigma/(r). The maximum current density, J/sub max/ moves from the core to the corona resulting in a screening of cores from Be and a drop in the voltage. A nearly hydrostatic balance with the RQS J/spl times/B forces is seen except when the rapidly rising current recompresses the wires.