Hello Matt,
As far as I'm aware, the first person to do HV switching in noble gas mass
spectrometry was Bob Pepin at the University of Minnesota, around 1970. He
found it quite successful, though this was for general noble gas (Ne through
Xe) work, so minor discrimination effects may not have been as significant
as for 40/39. I'm sure this was with a Nier source (what else, at
Minnesota!). There may be some details in his papers in the first two or
three years of Lunar Science Conference volumes. I don't know who may have
done it since; your query may well pull some others out of the woodwork.
Bob is still on staff in physics at Minnesota, at [log in to unmask]
Best regards,
Norm Evensen
=========================================
Norman M. Evensen
Department of Physics
University of Toronto
[log in to unmask]
(416) 978-3159 Office [voice mail]
(416) 978-2947 Lab
(416) 978-7606 Fax
----- Original Message -----
From: "matt heizler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, April 12, 2005 11:30 AM
Subject: High voltage peak jumping on MAP-215-50
> Hi all,
>
> Bill and I are considering fixing our magnet at approximately mass 38
> and going to voltage peak switching for 40 thru 36. Anyone with
> experience doing this? Obvious concern would be related to messing
> with source characteristics, however there are also potential
> benefits related to not driving the magnet.
>
> Thanks,
>
> Matt
>
>
> --
> Matt Heizler
> NM Bureau of Mines and Mineral Resources
> NM Tech
> 801 Leroy Place
> Socorro, NM 87801
>
> Office 505-835-5244
> Argon Lab 505-835-5271
> Main Office 505-835-5420
> FAX 505-835-6333
> http://geoinfo.nmt.edu/staff/mheizler/home.html
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