One of the most critical questions in planetary sciences is how the solar system evolved from a nebula of interstellar gas and dust into planets, moons and asteroids, all with markedly different…

This federal contract award, valued at $1,877,456.63, was granted by the National Aeronautics and Space Administration (NASA) to the University of Illinois, doing business as The Board of Trustees of the University of Illinois, to advance understanding of solar system formation. The project addresses two main goals of NASA's Laboratory Analysis of Returned Samples (LARS) program: developing instrumentation and methodology for analyzing samples from the Genesis mission, which collected solar wind, and applying those techniques using resonance ionization mass spectrometry (RIMS) to measure trace elements in the solar wind. The technical objective is to upgrade an existing time-of-flight mass spectrometry instrument with RIMS capability and new ion optics to enable high-sensitivity, high-resolution analyses. There is no set-aside designation for this grant. The University of Illinois, as the prime contractor, will perform this research project, which aims to provide insights into the early solar nebula and solar system evolution.

One of the most critical questions in planetary sciences is how the solar system evolved from a nebula of interstellar gas and dust into planets, moons and asteroids, all with markedly different compositions. To advance our understanding of solar system formation, the NASA genesis mission has collected samples of the solar material, represented by the solar wind (SW), and returned them for analyses in terrestrial laboratories. This project addresses two main goals of the NASA lars program, the development of instrumentation and methodology for analyses of genesis SW samples and their application to actual analyses by resonance ionization mass spectrometry (rims). The scientific objective of this project is to perform such analyses for SW MG, SE, SR, RB, ZR, and y. SW MG will be measured as a reference for comparison with other trace SW elements. Analyses for SE, SR and RB will aim at improved understanding of nonvolatile/ volatile element fractionation in the early solar nebula and testing the idea of preferential accretion of gas or dust by the sun. To this end, the abundances of KR will be obtained by interpolation from abundances of the neighboring elements (SE, SR and RB) measured by rims and compared to actual abundances of SW KR measured by others and corrected for first ionization potential fractionation. If, e.g., the measured KR abundance is higher than the interpolated KR abundance, this would be evidence that the sun preferentially accreted volatiles, possibly due to formation of outer solar system planetesimals. Analyses for ZR and y will aim at reinitiating a discussion of why the clear r- and s-process double peak structure in the solar system element abundance curve associated with the magic neutron numbers n=82 and n=126 is not apparent for the n=50 region. The technical objective of this project is to enable such analyses by major improvement of rims instrumentation. To this end, an existing time-of-flight mass spectrometry instrument in UIC department of chemistry will be upgraded with rims capability and new ION optics enabling high sensitivity analyses with high mass resolution. We will take advantage of two new approaches developed by the PI of this project earlier to enable reproducible quantitative analyses despite severe contamination of the genesis samples: the gentle dual beam depth profiling technique applicable to SI and DOS collectors and dry chemical etching of DOS collectors with XEF2 for backside depth profiling. Also, a planetary major equipment request will be attached to this project to implement the major instrumental upgrades needed for improving data quality, as follows. On the mass spectrometry side, (1) signal-to-noise ratios will be significantly improved - by modifying ION optics to more efficiently suppress secondary ions and to operate in orthogonal acceleration regime, thus creating two-stage noise filtering. (2) quality and reproducibility of depth profiling on both front and back sides of the SW collectors will be significantly improved as well - by installing brighter ION sources with enhanced stigmatic focusing capabilities and higher current output. This will also reduce the sample consumption and significantly shorten the overall analysis time. On the resonance ionization side, efficiency of the ionization will be significantly improved by implementing a new intra-cavity photo-ionization approach.