Feature Photos
Two different types of photographs are in the database; they were obtained
by either:
- optical light microscopy or
- scanning electron microscopy
SEM images usually carry their own scale bar with them. Some SEM images
lacked this scale bar, though. In this case obviously no size information
can be determined from the image, unless the feature is a "standard" MOS
discharge. The central crater in these features is always 9-12 micrometers.
Optical micrographs were found to be taken at the following magnifications:
All images were scanned in such a way that the scanned area included the
white marging of the photograph. You can obtain
scale information from these three images showing a 10 micrometer scale:
Two different scanning electron microscopes
were used, which is reflected in the layout of the SEM scale bar and comment
displays.
Obviously not all MOS impact features were photodocumented. The MOS
discharge rings could easily be spotted and the SIMS analysis was usually
guided by scratchmarks so that there was no mandatory reason to obtain a
micrograph.
In case this entry indicates the presence of images but none is displayed
there might be two reasons this happened:
- Records said that a photo had been taken but no photograph could be
found and scanned
- The image was scanned but not converted to GIF format or the filename
of the scanned image does not match the entry in the
HTML page, which might happen as this process has to be done
manually and is thus highly sensitive to typing mistakes. If you
dare to search for a probably lost scanned image, look for an image
that does not match a pattern MnnnNnn.GIF,
MnnnNnn.TIF, TnnnNnn.GIF, MASSES.GIF,
or BOX.GIF with n standing for a digit.
Klaus G. Paul, 06-20-94