Proposed research: 1. ION microprobe measurements of o isotopes from ldef AL targets. We will measure D17O and D18O on 3 sets of AL ldef targets: i) ~10 targets from d. Humes experiment (ldef…

This is a $106,000 grant award from the National Aeronautics and Space Administration (NASA) Shared Services Center to Arizona State University (ASU) for research related to the analysis of oxygen isotopes from samples returned from the Long Duration Exposure Facility (LDEF) mission. The research involves using ion microprobe measurements to analyze oxygen isotope ratios (D17O and D18O) in aluminum targets from different LDEF experiments. It also includes modeling the implantation of oxygen ions into the aluminum oxide layer using the SRIM code, and applying the results to atmospheric models for Mars in the context of the upcoming MAVEN mission. No set-aside designation is mentioned. ASU, a comprehensive public research university, is known for its expertise in space and planetary sciences research and often receives prime and subcontract awards from NASA and other federal agencies to conduct scientific studies and support space exploration initiatives.

Proposed research: 1. ION microprobe measurements of o isotopes from ldef AL targets. We will measure D17O and D18O on 3 sets of AL ldef targets: i) ~10 targets from d. Humes experiment (ldef S0001), together with an unflown piece of identical AL (from d. Humes); II) several targets from f. Horz experiment (ldef A0187-1), using the backside of a target as a standard; 3) several samples of ldef AL support structure (so-called intercostals), again using backside as a standard. The intercostals sample all locations on the spacecraft. 2. Srim code modeling of o ION implantation into AL oxide layer. We will use the srim code (freeware available from j. F. Ziegler) to calculate the penetration of o atoms of known kinetic energy into an ldef AL target, and to calculate mixing effects due to the ION microprobe CS+ ION beam, allowing US to determine the peak depletion of D18O. 3. Modeling of results and implications for mars. Although the focus of this proposal is on the measurements from the ldef targets, and on the srim modeling, we will interpret the results using an atmospheric model that includes diffusive separation, and we will apply the results to a similar model for mars for comparison with eventual maven data.