HI Istvan--

There was some discussion earlier about source magnets.  You may want to 
double check them (orientation, or if someone cleaned/roasted them, 
magnetism). 

take care

gerry

Fórizs István wrote:
> Dear Andrew,
>
> thank you very much for your advice. I have checked the possible 90 
> degree off, but this is not the case.
> The problem must be something else. I will let you know - hopefully 
> soon - what the problem is.
>
> Best wishes
> Istvan
>
> Andrew Schauer írta:
>> With your 18 years, I hardly feel qualified to say anything at 
>> all...but I recently observed the very same thing on our DeltaPlus 
>> (Advantage) with my significantly less than 18 yrs experience 
>> (p<0.05). My problem was putting the source together 90 degrees off 
>> from correct. The ceramic posts make a square, and thus, it possible 
>> to put it together 90 degrees off. My signal was about 10% of normal 
>> and focusing was, of course, way off. I would be interested in 
>> hearing the fix.
>>
>> andy
>>
>>  Andrew Schauer
>> ISOLAB
>> Department of Earth and Space Sciences
>> University of Washington
>> Seattle, WA 98195
>>
>>
>> 206.543.6327
>> [log in to unmask]
>>
>>
>>
>> ----- Original Message ----
>> From: Fórizs István <[log in to unmask]>
>> To: [log in to unmask]
>> Sent: Monday, January 19, 2009 8:23:48 AM
>> Subject: [ISOGEOCHEM] ion-source
>>
>> Dear Colleagues,
>>
>> I have been mainatining stable isotope ratio mass spectrometers for 
>> 18 years. Usually I do the ion source cleaning, and untill now there 
>> have been no problem with it.
>> Recently (first week of January) together with one of my colleagues 
>> we cleaned the ion source of our Finnigan delta plus XP.
>> After the maintainance we noticed that the height of the peak of the 
>> reference gas CO2 is about half of that it was before the celaning. 
>> The same is true for the H2 reference gas. At the same time the 
>> focusing does work well. E.g. the Y Deflection 1 and 2 was around 
>> 40%, BUT now Y Deflection 1 is at 100%, and Y deflection 2 is 96%.
>> We tried to do measurements, but we got strage values.
>>
>> I think that when we assembled the ion source, we did something 
>> wrong. Therefore we took off the ion source, disassembled it, but we 
>> did not notice any unusual. We assembled again the ion source and the 
>> result is the same. Half peak and bad "focussing" values.
>>
>> I would appreciate very much if somebody can tell us good hints on 
>> what we did incorrectly.
>>
>> Best regards
>> Istvan
>>
>> -- 
>> ------------------------------------------------------------------------- 
>>
>> 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
>> ------------------------------------------------------------------------- 
>>
>>
>>
>>
>>   
>