Problem sem4160 SNF 2011-05-10 10:17:54: beam current instability and low resolution

[jwc at snf.stanford.edu]

FE-GUN extraction current rapidly falls in operation 
Poor resolution at any acceleration voltage -- much worse than the state of the tool before the PM was performed.
Possibly the column became contaminated during the PM?
Several Users report unacceptable performance on this tool.
Further measurements tomorrow.
James Conway and Paul Rissman