Problem raith 2003-08-16 20:44:27: EHT is OK with smaller Extractor V

[okilic at snf.stanford.edu]

EHT trips in about 2 minutes after running up. Vacuum end else conditions look OK.
Decreased Extractor from 5.40kV to 4.00kV. No trips any more, system stable (using 10kV, don't know if EHT would trip for highe EHT targets). 
As expected current decreased (from ~175pA to ~95pA).
Caution: Setting Extractor to 5.40kV trips the EHT again.