Friday, October 4, 2019
Dr. Christopher Annesley
Air Force Research Laboratory
Kirtland Air Force Base
Satellite thruster plumes undergo a variety of reactions as they propagate through the space environment. We are conducting a series of investigations to better understand the effects of these reactions on the chemical makeup of the plume. These investigations have focused on the effects of ultraviolet and vacuum ultraviolet light on both conventional plume products and those of electrospray thrusters. For example, we have investigated photofragment fluorescence of key plume species after vacuum ultraviolet excitation. Additionally, we have looked at the photophysics of ionic liquid ion pairs. Here, we find that ultraviolet excitation can cause electron transfer to occur and that ionic liquid ion pairs then dissociate through neutrals. These species are implicated in the electrochemical breakdown of these possible electrolytes. Lastly, we have studied ionic liquid clustering and declustering using ion traps and collision induced dissociation.
Dr. Christopher Annesley is a research chemist at the Air Force Research Laboratory (AFRL). He earned his Ph.D. in physical chemistry at the University of Wisconsin – Madison studying vibrationally mediated reaction dynamics. He then completed a postdoc at Argonne National Laboratory studying high temperature pyrolysis of gas-phase fuels. At AFRL, Dr. Annesley has been using physical chemistry techniques in order to better understand thruster plume products and how the space environment, particularly ultraviolet and vacuum ultraviolet photons, change these products.
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