Several times in the last 4 months I have had an intermittent problem during stage-scan mapping on our Cameca SX100 using Probe Image.
As may be seen in the attached JPGs, one line has vastly higher intensity than the rest of the map.
Because of auto-scaling, this leads to the rest of the map appearing to be black.
Recently, the problem occurred simultaneously on Spectrometers 1 and 2 (LTAP and PET), under the following conditions:
20 kV, 80 nA, 1500 x 1500 pixels, 0.4 x 0.4 microns/pixel, 20 msec dwell, fully focused beam.
Interestingly, Spectrometers 3, 4 and 5, and the BSE signal were not affected.
Previously, a similar error had occurred on Spectrometers 1, 2, and 3 but not 4 nor the SEI signal.
And a couple of days later, on Spectrometers 1, 3 and 5, but not the SEI signal.
Each day the error has occurred, it is at a different line position, but for the spectrometers affected in that particular session, is in the identical position.
I have ruled out a systemic power spike, as I would expect all of the detectors to be affected.
Does anyone have an explanation, or observations of similar behavior? Or better yet, a solution to this occasional problem?
Thanks,
Andrew