CAREER: The Impact of Electrons on Laboratory Plasma Jets of Astrophysical Relevance

点击翻译按钮获取中文摘要

This CAREER award supports exploration of the underlying physics of the formation and stability of astrophysical plasma jets in a laboratory setting. Astrophysical jets are thought to be generated by supermassive black holes sweeping interstellar matter into a jet, intimately connecting the properties of the parent black hole and the jet itself. While black holes are difficult to observe, it is much easier to do so for astrophysical jets that can be hundreds of light years in length. The jet formation models benchmarked in this research could allow for precise determination of masses of black holes that give rise to astrophysical jets, leading to a better understanding of the distribution of dark matter throughout the Universe. While the deep gravitational well created by a black hole is missing in laboratory experiments, it is possible to form high energy density flows with very similar parameters. Thus, the basic mechanisms of jet formation can be studied in the laboratory using scaled-down versions of astrophysical flows. This research effort will also include and immerse students, including high school and undergraduate students, in an environment crossing over many scientific disciplines and continents, giving them new perspectives in high energy density physics and plasma astrophysics. The typical assumptions used to describe astrophysical jet dynamics tend to be oversimplified and often ignore the impact of electrons in astrophysical flows. While laboratory experiments cannot reproduce the gravitational well of a black hole, they can still generate flows of astrophysical relevance. This research program will investigate the impact of electrons on turbulent, supersonic jets generated by pulsed-power drivers focusing on three key questions: (1) Can electron effects improve collimation of turbulent jets? (2) Is it possible for electron flows to be a source of macroscopic instabilities? and (3) Can the physics models benchmarked in pulsed-power experiments be carried over to laser-driven jets and, ultimately, to astrophysical systems? The exceptional temporal and spatial accuracy of the diagnostics to be used in this study will allow not only to measure the electron density and magnetic field across space and time, but to also infer the electron flow velocity and electrical currents. All four quantities will be used to test electron effects across a wide range of scales. The main goal of this research is to clearly demonstrate when and where electron effects play an important role in high energy density plasmas and how these effects scale all the way to astrophysical systems. The experimental work will be conducted on the High Amperage Driver for Extreme States (HADES) facility constructed with support from the NSF Major Research Instrumentation program. The multi-disciplinary nature of the research will expose students to different scientific perspectives and nurture a culturally diverse research environment. Through mentoring, outreach, recruitment and experience abroad, this program will train students in becoming effective mentors and inspired scientists.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.