Istvan,

I have a similar problem with my Delta Plus XP.  My solution was to set the
HV to 2.2kV then turn on the source.  Once the emission is on reset the HV
to 3.0kV.  Using ISODAT v2.0, the HV setting can be change when you
right-click the mouse within the HV display frame of the ISODAT user
interface.

This idea may get the Delta running again but it does not solve the root
problem with your source.

Mark Haught
Stable Isotope Laboratory
University of Washington
School of Oceanography



-----Original Message-----
From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf
Of Fórizs István
Sent: Wednesday, January 13, 2010 7:28 AM
To: [log in to unmask]
Subject: [ISOGEOCHEM] ionsource, Finnigan delta plus XP

Dear Finnigan User Colleagues,

recently we have cleaned the ionsource of our Finnigan delta plus XP mass
spectrometer (as ususally at the beginning of the year). But the ionsource
does not want to work properly after switching on.
1) the HV is 0.33 kV instead of 2.9 kV.
2) The current on the anode (trap) is 0 mA, while on the ionization box it
is the maximum, 1.5 mA. There should be some 0.7 mA current on the trap. We
have checked the positions of both anode and cathod and found them to be
good.

We have disassembled  and checked the ionsource two times, but have not
found any unusual. The anode (trap) connection is good (and all the other
connections) and there is no shortcut in the ionsource (on the front panel
of the MS the green LED of "Accel Voltage" is on).
The green LED "Emission" on the front panel is on for a moment just after
switching on the source, then turns off. Why?

If any of you has met with this symptome and has an idea about it, I would
appreciate very much his/her help.

Best regards
István
-- 

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Dr. FÓRIZS István  ..........  Istvan FORIZS Ph.D.
Magyar Tudományos Akadémia Geokémiai Kutatóintézet Institute for Geochemical
Research, Hungarian Academy of Sciences
Cím/Address: H-1112 Budapest, Budaörsi út 45.   Hungary
Tel./Phone: (36-1)-309-2600/ mellék/extension 1151
Fax: (36-1)-319-3137
Http://www.geokemia.hu/people/forizs_hu.html
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