CAREER: Theory, Techniques and Simulations of RF Impedance Probes for Plasma Characterization

University Of South Alabama, Mobile AL

Investigators

Abstract

This research will be the first effort to use Radio Frequency Impedance Probes to measure and characterize a wide range of ambient plasma environments. The potential to use RF impedance probe techniques for measuring plasma parameters, such as temperatures and collision frequencies, has not yet been demonstrated due to lack of a sufficiently rigorous scientific model of the probe plasma interaction. Nonlinear properties of the probe plasma interaction are poorly understood and these properties have not been exploited. The first component of this research is to develop novel RF Impedance Probe techniques to obtain the probe-plasma frequency response in space plasmas. Graduate and undergraduate students will use the Universal Software Radio (USRP) hardware architecture together with open source software as a platform for the instrument related research. The second component of the project is the development of a theoretical and computational tool called RFPIC-PROBE that accurately simulates the interaction of the RF Impedance Probe with the surrounding plasma environment in order to analyze the frequency response data. The design of electronic circuits for space based measurements of plasma properties requires creative techniques to compensate for the quickly changing ambient plasma environment and to mitigate the effects of plasma interaction with a spacecraft. The research also develops mathematical and computational techniques to account for the gradual transition from collisional to fully collisionless interactions in ionospheric plasmas. The applications of this research range from space plasma diagnostics to laboratory plasma measurements and control of industrial plasma processes. The RF Impedance probe will provide a powerful means to measuring the properties of these plasmas. The RFPIC-PROBE software will be made available in the public domain under General Public License for use by researchers in different areas of plasma diagnostics. Graduate and undergraduate students will use readily available open source game engines to develop a real time space exploration strategy game where players choose instruments for missions to explore and probe the environments of different planets. As part of outreach, a workshop session will be introduced through the Alabama Science in Motion program to allow high school students and teachers to try out computer experiments to measure the properties of a hypothetical plasma medium. All results and data from this research project will be hosted on the world wide web, and made freely available for public or industrial use and collaboration.