We study plasma chemistry reactions over a broad range of conditions in order to understand the natural and perturbed atmosphere. Several state-of-the-art fast flow reactors allow studies over an unprecedented range of conditions. (1) The selected ion flow drift tube can study ion-molecule reactions over the temperature range from 80-700 K and an energy range from thermal to approximately 1 eV. These data are used to derive internal energy dependences of ion/molecule reactions and to study reactive species such as atoms and radicals. (2) A high-temperature flowing afterglow can study ion-molecule reactions from room temperature up to 1800 K and electron reactions up to 1200 K. Combining the HFTA with the SIFDT data allows us to study internal energy dependences over a broader range of vibrational frequencies. (3) A turbulent flow reactor allows us to study reactivity from 10-760 Torr from room temperature to 700 K. The combination of these instruments makes it possible to study atmospheric ion chemistry under all atmospheric conditions. (4) We can also study electron processes in a flowing afterglow Langmuir probe apparatus. We study ion-molecule, electron attachment, ion-ion mutual neutralization, and electron-ion recombination. We use the data to understand numerous systems of interest to the Air Force and DOD. Examples include the natural ionosphere, plasmas around a variety of hypersonic vehicles, plasma assisted combustion, laser development, and the HAARP facility. We also look to develop techniques for mitigating and exploiting the effects of such plasmas and are developing chemical ionization techniques for detecting trace neutrals in the atmosphere, most recently for sensitive detection of chemical agents.

 

key words

Atmospheric chemistry; Atmospheric particles; Ionosphere; Atmospheric plasmas; Turbulent flows;

Citizenship:  Open to U.S. citizens

Level:  Open to Postdoctoral and Senior applicants