The source magnets on every one of Deltas prior to the V have had the S pole of the filament side pointing in towards the center of the source.  It is easy to remember “the filament is going south”.


But the magnet poles on our Delta V are opposite of prior models, with the N pole on the filament side going towards the center of the source.


I have always left the magnet poles pointing the same way as originally supplied and shown in the manuals.


Cheers, Ben


From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf Of Jen McKay
Sent: Wednesday, January 31, 2018 2:18 PM
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] Stability Issues - Delta Plus Source - continued.


Hi Michelle,


This is Jennifer responding.  What you describe about turning the source off and then back on (…although on a much shorter timescale) did work when the problematic source was in the other mass spec.  We also discussed a possible problem with the magnets but then just confirmed that they were in the proper way according to the manual and how we have always put them in.  Switching them seems very strange but at this point we are ready to try anything.  We will let you know how it goes.









Jennifer McKay
Assistant Professor (Senior Research)
Stable Isotope Lab Manager
CEOAS, Oregon State University
Corvallis, Oregon 97331


On Jan 31, 2018, at 12:31 PM, Chartrand, Michelle <[log in to unmask]> wrote:


In the Delta+XP operating manual I have, in Figure 8-3 (Ion Source), the position of the magnets is south towards the filament, north towards the trap, and is the orientation I always thought was correct.  When I switched them (i.e. north towards the filament, south towards the trap), my signal magically recovered and all was good in my world again.  However, with all the fiddling I did with the source, I cannot rule out that I had a little misalignment that magically fixed itself.