||Kirtland Air Force Base, NM 871175776
|Ryan Carl Hoffmann
Space is complex and a hostile environment. It consists of vacuum, large temperature fluctuations, and bombardment by energetic particles, including atomic oxygen, electrons, ions, vacuum ultraviolet light (VUV), all of which act to alter the materials spacecraft are constructed from. Our research effort focuses on the modification of spacecraft material properties caused by exposure to the space environment, predominantly bombardment by high energy electrons, ions, and VUV light.
Previously, experiments on common spacecraft polymers such as polyimide (Kapton®), or polytetrafluoroethylene (Teflon®) have shown dramatic changes in the electrical conductivity, an important parameter for spacecraft survivability, when radiated with high energy electrons. Current research is underway to understand the chemical underpinnings of these changes and extend that understanding to other material properties especially optical. We are searching for an Associate to undertake experiments and/or modeling to provide chemical understanding of polymer degradation and prediction of the material properties after exposure to a known radiation environment.
Optical properties of materials provide an exciting link to understand the state of a satellite using remote sensing. The end goal is to use various photometric measurements generated during this work to determine the material composition of a satellite and the state of each material.
The Associate will have access to a large vacuum chamber (2m diameter) equipped with a high energy electron gun, VUV lights, a temperature regulated plate, and several characterization tools. In addition the lab has access to AFM, SEM, UV/VIS and IR spectrometers, and optical characterization facilities, either in the lab or with collaborators on base. Ongoing collaborations with the University of New Mexico, other research universities, and the materials branch of AFRL provide access to practically any material characterization technique.
Cooper R, et al: Effects of Radiation Damage on Polyimide Resistivity. Journal of Spacecraft and Rockets, 2016, accepted, DOI: http://dx.doi.org/10.2514/1.A33541
Material science; Polymer; Space weather; Computation; Degradation; Radiation; Optics; Charge transport; Remote sensing;