A motivated experimentalist is sought to focus on the study of direct reactions between energetic ions and surface adsorbates. Topics of interest include bond formation, leading to the production of vibrationally excited exotic molecules, as well as collision-induced dissociation of molecular ions. Electronic excitations and other energy loss mechanisms during these collisions are also of interest. A background in Chemical Physics is optimal for this position. The successful applicant will be required to operate a unique ion-beam surface scattering apparatus, where monoenergetic beams of generic ions with translational energy in the range between 1-1000eV, are generated, transported, and directed towards solid surfaces covered with reactive adsorbates. Reaction products and their energetics are subsequently analyzed using mass spectrometry and hemispherical energy analyzers. Good knowledge of UHV techniques, mass spectrometry, surface analysis, and some understanding of low-pressure plasmas are important background. The initial appointment is for one year, but is renewable depending on funding and performance. The starting salary depends on experience and qualifications. The position includes standard Caltech Postdoctoral Scholar benefits.
1) Experimental studies of Eley-Rideal reactions in astrochemical environments
We seek to understand the role of such reactions in cometary and proto-planetary environments, where solar wind interactions with surface-emitted neutral molecules produce ions, which are accelerated in the solar wind electric field to gain translational energy. Collisions with dust grains or the cometary nucleus can then lead to the formation of unusual molecular products. Specifically, we are interested in energetic interactions of water, carbon monoxide, and carbon dioxide ions with interplanetary dust and cometary nucleus surfaces.
2) Computational studies of moderate energy (20eV - 200eV) ion-surface dynamics
We seek to understand energy partitioning and reactivity in energetic projectile collisions with surfaces containing adsorbates. Interactions of interest include energy and charge transfer, orientation effects, electronic and ro-vibrational excitations, bond breaking and new bond formation. Exotic reactions at surfaces driven by kinetic energy represent a new area of chemical physics. We want to explore non-minimum energy reaction pathways, such as those mediated by excited (Rydberg) states, that lead to surprising products.