Low energy NaI detection

[Neon John <johngd@bellsouth.net>]

I was asked one of those simple little questions today that just
kinda stopped me cold and made me draw a blank.  The question was,
can a NaI/PM detector be used for 0.5 keV X-ray detection?  My
impulse answer was no.  My experience tells me that conventional
detectors as used in effluent monitors typically have a 50-60 keV
equiv noise floor.  But before I answered the question with a
possibly wrong answer, I thought I'd ask this esteemed list :-) to
see if there is some technique I'm not aware of.  There's no
particular context to this (vacuum, exposed crystal in a dry box,
etc.), just kind of a blue-sky question.

Thanks,
John
-- 
John De Armond
johngdSPAMNOT@bellsouth.net
RDS Inc.
Cleveland, TN
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