Office: 245 Oceanography/Physics Building (683-4618)
Laboratory: 242 Oceanography/Physics Building (683-6020)
Research Sponsors: NASA Langley Research Center
NASA Johnson Research Center
E-mail: popovic@physics.odu.edu
Effects of weakly ionized gas on propulsion and aerodynamics. Dispersion and anomalous propagation of strong acoustic and shock waves in weakly ionized gas have drawn increasing attention in recent years, partly because of their potential for application in aerodynamics. We are studying the role of electronically excited states of atoms and molecules in coupling mechanisms based on energy-pooling processes, charge transfer processes between ions and neutral molecules contributing to the acceleration of neutral component, and multiple excitation processes which decay by autoionization. We also investigate the behavior of electronically excited particles in strong electric field created by the double electric layer associated with shock wave front in the ionized gas.
Oxygen Production from Martian Atmosphere. Research activity on in-situ resource utilization during Mars exploration is presently focused on finding an effective method for oxygen production. We are developing a method based on carbon dioxide dissociation and efficient extraction of oxygen in radio-frequency and microwave discharge plasmas. We are studying atomic and molecular processes involved in the kinetics of carbon dioxide dissociation, since the Martian atmosphere is composed mainly of carbon dioxide. The concept does not involve modifying the Martian atmosphere, does not require dust filtration, and no transport of reactive material from Earth is needed.
Ultraviolet Light Sources. We are studying atomic and molecular processes relevant for the development of new schemes of mercury-free ultraviolet light sources based on radio-frequency and microwave discharges. High pressure microwave-excited excimer light sources are a successful example of this research activity, which also includes low pressure discharges with efficient photon energy conversion into visible spectrum, or into a targeted spectral range. Work consists of a range of studies on molecular and gas-kinetic basis of the electric breakdown, stability and radiative transfer mechanisms in radio-frequency and microwave discharges.
"Electrical Breakdown of the Space Vacuum," E. E. Kunhardt, S. Popovi, and J. Bentson, IEEE Trans. Plasma Sci. 23, 970 (1995).
"Electrical Breakdown in Space Environment," E. E. Kunhardt, S. Popovi, and J. Bentson, in SPEAR II "High Power Space Insulation," ed. By H. A. Cohen, F. M. Lehr, and T. G. Engel, Lubbock, TX: Texas Tech Univ. Press, 1995.
"Radio-Frequency Discharge Reaction Cell for Oxygen Extraction from Martian
Atmosphere," L. Vukovi, R. L. Ash, Z. Shi, S. Popovi, and T. Dinh, SAE Paper 972499 (1997).
"Nd:YAG Laser-Based Dual-Line Rayleigh Scattering System," M. V. Ötügen, J. Kim, and S. Popovi, AIAA Journal 35, 776 (1997).
"Turbulent Temperature Measurements Using Nd:YAG Laser-Based Dual-Line Detection Rayleigh Scattering Technique," M. V. Ötügen, J. Kim, and S. Popovi, AIAA 97-0604 (1997).