NSF-BSF: Multi-ion Transport, Rotation, and Turbulence in Hydrodynamic Compression of Z-pinch

Princeton University, Princeton NJ

Investigators

Abstract

This award supports a collaborative effort between Princeton University and the Weizmann Institute of Science to study turbulence in a magnetized plasma - an ionized gas permeated by magnetic fields - confined in a laboratory experiment called a Z-pinch. Recent theoretical work has predicted new fundamental phenomena in a multi-ion magnetized plasma, or partially ionized plasma, on timescales characteristic of the turbulent plasma evolution. On these timescales, the transport of heat and particles may vary among ion species, with energy residing in the thermal motion of one ionic species or another, or in electrons, or in the turbulent flows. The Weizmann Z-pinch experiment is distinctively positioned to explore these theoretical predictions in the laboratory and to distinguish their unusual features through precision spectroscopic measurements. The Princeton-Weizmann collaboration aspires both to validate the theoretical predictions and to understand any unexpected phenomena uncovered. The fundamental understanding of a magnetized Z-pinch plasma could underpin applications to x-ray generation and nuclear fusion energy development. Precision spectroscopic measurements of a turbulent, imploding Z-pinch plasma at the Weizmann Institute of Science uncovered fundamental, new, and curious plasma effects. Inviscid on time and space scales of interest in ways that usual fluids tend not to be, the Z-pinch plasma at Weizmann serves as a virtual laboratory for unusual viscid and inviscid plasma dynamics. These dynamics, which include the compression of plasma laden with turbulent kinetic energy, have led to the prediction of the sudden viscous dissipation effect in compressing plasma. Further important plasma effects have been predicted by the Princeton team in magnetized multi-species plasma and partially magnetized plasma, including the charge incompressibility heat pump effect and the partial ionization deconfinement effect. These effects can be important: trace impurities can quickly poison fusion reactions or quench radiation generation in an imploding plasma -- and using too many trace impurities can surprisingly render invalid inferences of plasma parameters. Thus, this project's objective is to theoretically refine and experimentally validate the theoretical predictions of charge state profiles in a turbulent Z-pinch plasma. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.