High Energy Recollision And Excitation Processes At Ultrahigh Light Intensities

University Of Delaware, Newark DE

Investigators

Abstract

This award investigates how very intense lasers excite atoms and molecules, using laboratory experiments and theoretical modeling. The work supports three thrust areas that affect intellectual merit and the broader impact: applied optical technology, fundamental high intensity laser science, and next generation global competitiveness for individuals in science, technology, engineering, and mathematics (STEM) in the United States. Applied optical technology is addressed with the unique, trillion watt peak power lasers in the research. These lasers generate some of the highest intensities of visible and ultraviolet light realized in the lab. The contribution to scientific knowledge comes about by addressing how intense light excites elements (e.g. lithium, carbon, nitrogen, oxygen) and polymer hydrocarbons (e.g. methane, propane). Specifically, the research probes high energy electron dynamics and ion fragmentation in intense laser-matter interactions. Special attention is given to quantifying how many of the electrons most tightly bound to the nucleus are excited. The measurements are made possible by the investment in new scientific laboratory apparatus designed to probe highly accelerated (e.g. million volt) electrons and record the complex ion fragmentation. The theory effort uses large scale (supercomputer) trajectory ensembles to model excitation and relativistic effects in the interaction. The outcomes are relevant to disciplines including plasma physics, fusion energy, physical chemistry, atomic physics, and optical science. The research addresses efforts to develop new laser sources and attosecond science, which directly measure how electrons move in atoms and molecules. The high field research in the award is pursued by the international community; students involved in this research are exposed to international efforts in optics and laser science. As part of a broader impact, the award strives to improve global competitiveness for the next STEM generation in the United States. The experiments and theory in the award provides intensive training for graduate and undergraduate students on applied and fundamental topics including ultrafast optics, laser pulse diagnostics, computer programming, data acquisition hardware, laser alignment, opto-mechanical design, collision physics, and electron dynamics in atomic and molecular systems. The research provides skills helpful across science and technology disciplines from national defense contracting to medical physics to the laser material processing industry.