Proposal Number: CTS-0613277 Principal Investigator: Lawler, James E. Affiliation: University of Wisconsin-Madison Proposal Title: The Power Balance of Plasmas at Extreme High Pressure
This project was funded through the NSF/DOE Partnership in Basic Plasma Science and Engineering. The project will attempt an experimental and theoretical study of plasma science in the Extreme High Pressure (EHP) range of 1 kbar (1000 atmospheres pressure). The primary research goal is the development of a quantitative, microscopic understanding of the power balance of steady-state kbar plasmas in mercury (Hg). Radiation controls the power balance of EHP plasmas, and thus an understanding of the interaction of electromagnetic radiation with such plasmas is crucial to the primary goal. Low pressure plasmas in Hg and other atomic gases emit primarily atomic line radiation. As the total pressure in the plasma is increased, atomic lines become broader and continuum processes contribute a larger fraction of the radiation. As the pressures approaches a kbar, there will be few recognizable atomic lines and continuum processes will dominate. Intellectually, the project's main contributions will be to advance the field of low temperature or non-fusion plasma science into a little studied region of parameter space. With respect to the Broader Impacts of the work, the benefits will be in the important technology and science of lighting. Lighting consumes ~25% of all electrical energy. Improved light sources are of great value to U. S. society by helping address economic and national security problems from our increasing reliance on oil & gas imports, and are of greater value to humanity by helping address major energy and environmental problems. Modern fluorescent and Metal Halide HID lamps (120 lumen/Watt) are at least six times as efficient as incandescent lamps (< 20 lumen/Watt). Low pressure sodium lamps achieve 200 lumen/Watt but have very low Color Rendering Indices. There are no known theoretical barriers to the development of discharge plasma light sources with good color and with efficacies in the 200 to 300 lumen/Watt range. Specialty lamps operating at 200 bar are in use today. An EHP Hg lamp operating in the kbar range could have potential as an efficient white light source. The project will involve graduate students and/or post docs in important plasma science research. Outreach activities under this program will include talks on lighting science and energy efficiency at primary and secondary schools.
