Spectroscopic Measurements of Plasmas in the Power Flow Regions on the Z Machine*

Pulsed power devices depend on the ability to deliver high voltages and currents to a variety of complex loads with minimal transmission losses.  The Z Machine at Sandia National Laboratories can deliver up to 26MA within a few 10’s of nanoseconds to multiple z-pinch type loads.  An effort is underway to measure plasma parameters such as temperatures and densities within the power flow regions on the Z Machine.  A proper physics understanding of efficient high current delivery is necessary to ensure that higher current devices such as Z-Next will perform as designed.  In the power flow regions, plasmas form on the electrode surfaces and propagate into the vacuum gap, providing a current loss mechanism.  These plasmas are measured spectroscopically using a 1m Czerny-Turner spectrometer with a fast (nanosecond) streak camera output.  Data is analyzed using detailed, time-dependent, collisional-radiative (CR) and radiation transport modeling.  Recent results will be presented.