Kendra,

I had this problem on my VG PRISM last year.  I had run on one filament for
more than two years, so I was very surprised when I suddenly went through
the last few filaments I had in just a few days. As it turns out, my trap
current had increased to 1000 microamps, even though the computer  readout
said it was at 800 uamps.  I don't understand what had caused it to creep
up, and the only explanation I could get out of Micromass was a known
problem with the electronics.  I now run at 600 uamps (on computer) which
corresponds to about ~700 uamps on the gauge---and I am no longer blowing
filaments. However, I now monitor the trap current and emission current daily.

Best Regards

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Gail F. Eaton
Analytical & Nuclear Chemistry Division
Lawrence Livermore National Laboratory
P.O. Box 808, L-231
Livermore, CA 94550
FedEx & Packages: 7000 East Avenue
Phone: 925-422-9546
Fax:  925-422-3160
e-mail:  [log in to unmask]
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