|Title:||Accurate analysis of shallowly implanted solar wind ions by SIMS backside depth profiling|
|Authors:||V. S. Heber, K. D. McKeegan, D. S. Burnett, J. Duprat, Y. Guan, A. Jurewicz, C. T. Olinger, S. P. Smith|
|Publication:||Chemical Geology, v. 390, p. 61‐73.|
A method to quantitatively determine the fluences of shallowly‐implanted solar wind ions returned to Earth by the Genesis Discovery mission is described. Through backside depth‐profiling, we recover nearly complete depth profiles of implanted solar wind for several nonvolatile elements, including Mg,Al,Ca, Cr, and to a lesser extent, Na, in silicon targets that collected bulk solar wind and solar wind from specific velocity regimes. We also determine fluences of the volatile elements C, N, and O in silicon targets that collected bulk solar wind. By use of appropriately calibrated ion implanted standards, fluences as low as 2 × 1010 atoms cm −2 can be determined with precision and accuracy typically in the few percent range. Specific approaches to sample preparation, sputtering artifacts during depth profiling by secondary ion mass spectrometry, and quantification including production of ion implant standards are discussed.