Compositional analysis of projectile residues on LDEF instrument AO187-1

摘要: Impact craters greater than 30 microns and associated projectile residues were analyzed by Scanning Electron Microscopy (SEM) Energy Dispersive X-ray Analysis (EDXA). Objectives to analyze a statistically significant number of projectiles evaluate their chemical variability possible clustering into discrete particle types. Bay A11 exposed six collector surfaces anodized 1100-T4 (greater 99 percent pure) aluminum sheets, 0.32 cm thick, yielding an surface area 1.1 sq. m. Four the panels have been retained at JSC, optically scanned, one (A11E00E) was prepared for SEM/EDX analysis. A03 occupied high purity (99.99 percent) gold 0.5 mm 0.85 Sample processing included optical scanning (6X), labeling, dislodging (by punch-die device) each individual impact 75 gold. The 209 dislodged form A11E00E, having crater diameters up 3500 microns. Optical examination detected 238 craters, 198 which JSC via SEM/EDX. analytical procedures maximizing geometric efficiency (take-off angles), using relatively long count times (500-1000 sec) sufficiently accelerating currents (25-30Kev). Despite diligent examination, large did not exhibit measurable signals above background. Detectable resides classified as either micrometeoritic or man-made debris.