Chemically etched modulation in wire radius for wire array Z-pinch perturbation studies

A technique for manufacturing wires with imposed modulation in radius with axial wavelengths as short as 1 mm is presented. Extruded aluminum 5056 with 15 mum diameter was masked and chemically etched to reduce the radius by similar to20% in selected regions. Characterized by scanning electron microscopy, the modulation in radius is a step function with a similar to10 mum wide conical transition between thick and thin segments, with some pitting in etched regions. Techniques for mounting and aligning these wires in arrays for fast z-pinch experiments will be discussed. Axially mass-modulated wire arrays of this type will allow the study of seeded Rayleigh-Taylor instabilities in z pinches, corona formation, wire initiation with varying current density in the wire core, and correlation of perturbations between adjacent wires. This tool will support magnetohydrodynamics code validation in complex three-dimensional geometries, and perhaps x-ray pulse shaping. (C) 2004 American Institute of Physics.