Experimental study of plasma evolution in a single post-hole convolute on a 1 MA linear transformer driver

Summary form only given. Post-hole convolutes are commonly used in large scale pulsed power devices to combine the current from several sources. The primary examples of convolute use are Load Current Multipliers (LCMs) and current combination from multiple Self-Magnetically Insulated Transmission Lines (MITLs). Sandia National Laboratory´s Z-Machine utilizes a double post-hole convolute to combine the current from four MITLs to one load. Current losses in the convolute region on large scale pulsed power devices range from 5-20%. The Michigan Accelerator for Inductive Z-pinch Experiments (MAIZE) is a Mega-Ampere class fast Linear Transformer Driver (LTD) with a modular load design. A single post-hole convolute load has been designed for MAIZE. Diagnostic access for the post-hole convolute load includes: spatially- and temporally-resolved, fiber optically-coupled visible and UV spectroscopy and an array of calibrated b-dot monitors. The goal of these experiments is to examine plasma gap closure in the post-hole region. By using different materials for the anode and cathode, the source of the plasma (and thus the source of gap closure) can be determined by the ion composition of the plasma. Additionally, spectroscopic measurements of the plasma temperature and density are on interest to the simulation community. Material presented will include Particle-In-Cell simulations using MAGIC PIC 3D, experimental design, and preliminary results.