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Title: Understanding heterogeneity in Genesis diamond-like carbon film using SIMS analysis of implants

An amorphous diamond-like carbon film deposited on silicon made at Sandia National Laboratory by pulsed laser deposition was one of several solar wind (SW) collectors used by the Genesis Mission (NASA Discovery Class Mission #5). The film was ~1 μm thick, amorphous, anhydrous, and had a high ratio of sp 3–sp 2 bonds (>50%). For 27 months of exposure to space at the first We passively irradiated lagrange point, the collectors, with SW (H fluence ~2 × 10 16 ions cm -2; He fluence ~8 × 10 14 ions cm -2). The radiation damage caused by the implanted H ions peaked at 12–14 nm below the surface of the film and that of He about 20–23 nm. To enable quantitative measurement of the SW fluences by secondary ion mass spectroscopy, minor isotopes of Mg ( 25Mg and 26Mg) were commercially implanted into flight-spare collectors at 75 keV and a fluence of 1 × 10 14 ions cm -2. Furthermore, the shapes of analytical depth profiles, the rate at which the profiles were sputtered by a given beam current, and the intensity of ion yields are used to characterize the structure of the material in small areas (~200 × 200 ±more » 50 μm). Data were consistent with the hypothesis that minor structural changes in the film were induced by SW exposure.« less
Authors:
 [1] ;  [2] ; ORCiD logo [3] ;  [4] ;  [5] ;  [6] ;  [7] ; ORCiD logo [8]
  1. Arizona State Univ., Tempe, AZ (United States). Center for Meteorite Studies, School of Earth and Space Exploration
  2. California Inst. of Technology (CalTech), Pasadena, CA (United States). Dept. of Geology and Planetary Sciences
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). ISR-2
  4. Arizona State Univ., Tempe, AZ (United States). School of Earth and Space Exploration
  5. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Nanostructure and Semiconductor Physics
  6. Arizona State Univ., Tempe, AZ (United States). School of Molecular Science
  7. Dartmouth College, Hanover, NH (United States). Electron Microscope Facility, Geisel School of Medicine
  8. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Report Number(s):
LA-UR-17-27685
Journal ID: ISSN 0022-2461
Grant/Contract Number:
AC52-06NA25396; #NNX14AF26G
Type:
Accepted Manuscript
Journal Name:
Journal of Materials Science
Additional Journal Information:
Journal Volume: 52; Journal Issue: 19; Journal ID: ISSN 0022-2461
Publisher:
Springer
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
National Aeronautics and Space Administration (NASA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Planetary Sciences
OSTI Identifier:
1396142